Docstoc

22-06-0005-01-0000-etri-ft-philips-samsung-proposal

Document Sample
22-06-0005-01-0000-etri-ft-philips-samsung-proposal Powered By Docstoc
					January 2006                                                                                                              doc.: IEEE 802.22-06/0005r1

          A PHY/MAC Proposal for IEEE 802.22
                  WRAN Systems
                         IEEE P802.22 Wireless RANs                                                                      Date: 2006-01-17
Authors:
Name                                 Company                                                Address              Phone                            Email

Martial Bellec                       France Telecom                                         France               +33-2-99-124806                  Martial.bellec@francetelecom.com

Yoon Chae Cheong                     SAIT                                                   Korea                +82-31-280-9501                  Yc.cheong@samsung.com

Carlos Cordeiro                      Philips                                                USA                  +1-914-945-6091                  Carlos.Cordeiro@philips.com

Chang-Joo Kim                        ETRI                                                   Korea                +82-42-860-1230                  cjkim@etri.re.kr

Hak-Sun Kim                          Samsung Electro-mechanics                              Korea                +82-31-210-3500                  hszic.kim@samsung.com

Joy Laskar                           Georgia Institute of Technology                        USA                  +1-404-894-5268                  joy.laskar@ece.gatech.edu

Notice: This document has been prepared to assist IEEE 802.22. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in
this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein.

Release: The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE
Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit
others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.22.

Patent Policy and Procedures: The contributor is familiar with the IEEE 802 Patent Policy and Procedures http://standards.ieee.org/guides/bylaws/sb-bylaws.pdf including the
statement "IEEE standards may include the known use of patent(s), including patent applications, provided the IEEE receives assurance from the patent holder or applicant with respect to
patents essential for compliance with both mandatory and optional portions of the standard." Early disclosure to the Working Group of patent information that might be relevant to the standard
is essential to reduce the possibility for delays in the development process and increase the likelihood that the draft publication will be approved for publication. Please notify the Chair
Carl R. Stevenson as early as possible, in written or electronic form, if patented technology (or technology under patent application) might be incorporated into a draft standard being
developed within the IEEE 802.22 Working Group. If you have questions, contact the IEEE Patent Committee Administrator at patcom@iee.org.
>
Submission                                                                                  Slide 1                                 ETRI, France Telecom, Philips, Samsung
January 2006                                                     doc.: IEEE 802.22-06/0005r1

Co-Authors
        Name              Company           Address          Phone                         email
   Myung-Sun Song           ETRI            Korea        +82-42-860-5046             mssong@etri.re.kr
     Soon-Ik Jeon           ETRI            Korea        +82-42-860-5947             sijeon@etri.re.kr
   Gwang-Zeen Ko            ETRI            Korea        +82-42-860-4862             gogogo@etri.re.kr
  Sung-Hyun Hwang           ETRI            Korea        +82-42-860-1133             shwang@etri.re.kr
    Bub-Joo Kang            ETRI            Korea        +82-42-860-5446            kbj64370@etri.re.kr
   Chung Gu Kang            ETRI            Korea        +82-2-3290-3236           ccgkang@korea.ac.kr
   KyungHi Chang            ETRI            Korea        +82-32-860-8422            khchang@inha.ac.kr
     Yun Hee Kim            ETRI            Korea        +82-31-201-3793            yheekim@khu.ac.kr
     Moon Ho Lee            ETRI            Korea        +82-63-270-2463          moonho@chonbuk.ac.kr
   HyungRae Park            ETRI            Korea        +82-2-300-0143        hrpark@mail.hangkong.ac.kr

   Denis Callonnec    France Telecom        France       +33-4-76-764412    Denis.Callonnec@francetelecom.com

     Luis Escobar     France Telecom        France       +33-2-45-294622     Luis.Escobar@francetelecom.com

    Francois Marx     France Telecom        France       +33-4-76-764109    Francois.Marx@francetelecom.com

     Patrick Pirat    France Telecom        France       +33-2-99-124806       Ppirat.ext@francetelecom.com
                     Georgia Institute of
     Kyutae Lim                              USA         +1-404-385-6008           ktlim @ece.gatech.edu
                           Technology
                     Georgia Institute of
    Youngsik Hur                             USA         +1-404-385-6008           yshur @ece.gatech.edu
                           Technology
Submission                                     Slide 2                ETRI, France Telecom, Philips, Samsung
January 2006                                                      doc.: IEEE 802.22-06/0005r1

Co-Authors
         Name              Company           Address           Phone                         email
   Dagnachew Birru          Philips           USA         +1-914-945-6401       Dagnachew.Birru@philips.com
   Kiran Challapali         Philips           USA         +1-914-945-6357       Kiran.Challapali@philips.com
   Vasanth Gaddam           Philips           USA         +1-914-945-6424       Vasanth.Gaddam@philips.com
    Monisha Ghosh           Philips           USA         +1-914-945-6415        Monisha.Ghosh@philips.com
    Gene Turkenich          Philips           USA         +1-914-945-6370        Gene.Turkenich@philips.com
   Duckdong Hwang            SAIT            Korea         +82 31 280 9513     duckdong.hwang@samsung.com
 Ashish Pandharipande        SAIT            Korea        +82 010-6335-7784            pashish@ieee.org
                        Samsung Electro-
     Jeong Suk Lee                           Korea        +82-31-210-3217          js0305.lee@samsung.com
                             Mechanics
                        Samsung Electro-
     Chang Ho Lee                            Korea        +82-31-210-3217         changholee@samsung.com
                             Mechanics
                        Samsung Electro-
   Wangmyong Woo                             Korea        +82-31-210-3217           wmwoo@samsung.com
                             Mechanics
                           Samsung
                                                                                  d.mazzarese@samsung.com
   David Mazzarese         Electronics Co.   Korea        +82 10 3279 5210
                                Ltd.
                        Samsung Telecom
       Baowei Ji                              USA         +1-972-761-7167          Baowei.ji@samsung.com
                              America




Submission                                      Slide 3                ETRI, France Telecom, Philips, Samsung
January 2006                                  doc.: IEEE 802.22-06/0005r1


                    Presentation Outline

 • Introduction
       – A Glimpse of IEEE 802.22


 • The PHY Proposal

 • The MAC Proposal

 • Conclusions




Submission                          Slide 4      ETRI, France Telecom, Philips, Samsung
January 2006                                  doc.: IEEE 802.22-06/0005r1


                    Presentation Outline

 • Introduction
       – A Glimpse of IEEE 802.22


 • The PHY Proposal

 • The MAC Proposal

 • Conclusions




Submission                          Slide 5      ETRI, France Telecom, Philips, Samsung
January 2006             doc.: IEEE 802.22-06/0005r1




Submission     Slide 6      ETRI, France Telecom, Philips, Samsung
January 2006                                doc.: IEEE 802.22-06/0005r1


                       The IEEE 802.22
 • From 18 Mbps to 24 Mbps                                RAN
                                                         < 100 km
                                              802.22 (proposed) - 18 to 24 Mbps

                                                          WAN
 • Propagation delays in excess                           < 15 km

                                                    802.20 (proposed)
   of 300 µs                                 GSM, GPRS, CDMA, 2.5G, 3G – 10
                                                    kbps to 2.4 Mbps
                                                          MAN
                                                           < 5 km
 • Operates in TV bands                             802.16a/d/e - 70 Mbps
                                                      LMDS - 38 Mbps
       – 54 to 862 MHz                                     LAN
                                                          < 150 m
       – 6 MHz, 7 MHz and 8 MHz                         11 – 54 Mbps

         channel bandwidth                              802.11a/b/e/g
                                                        HiperLAN/2
                                               802.11n (proposed) > 100 Mbps

                                                           PAN
                                                           < 10 m

                                                802.15.1 (Bluetooth) – 1 Mbps
                                                     802.15.3 > 20 Mbps
                                                802.15.3a (UWB) < 480 Mbps
                                                 802.15.4 (Zigbee) < 250 kbps



Submission                        Slide 7       ETRI, France Telecom, Philips, Samsung
January 2006                                              doc.: IEEE 802.22-06/0005r1


                    Deployment Scenario
                                                                                                           CPE



 • Master/Slave relationship                                                     CPE




                                                                                                      BS




 • Entities
                                                                     CPE

                                                                                                                      CPE

                                                       33 - 100 Km


       – Base Station (BS)                      CPE
                                                                                                CPE




       – Consumer Premise Equipment                                         BS



         (CPE)                                                                                                         CPE




                                                                                         CPE

                                                                                                                 BS
                                                 CPE



 • 4W CPE transmit power                                               BS



                                                                                                                             CPE



                                                                                         CPE
                                                CPE




                                                                             Backbone Network




Submission                            Slide 8                        ETRI, France Telecom, Philips, Samsung
January 2006                                  doc.: IEEE 802.22-06/0005r1


                    Presentation Outline

 • Introduction
       – A Glimpse of IEEE 802.22


 • The PHY Proposal

 • The MAC Proposal

 • Conclusions




Submission                          Slide 9      ETRI, France Telecom, Philips, Samsung
January 2006                               doc.: IEEE 802.22-06/0005r1


                        PHY Outline
 • Overview

 • Channel bonding

 • Supper-frame, preamble, spreading

 • Preliminary OFDM parameters, data rates

 • Sub-Channelization, pilot insertion

 • Error Correction Coding

 • Multiple antenna

 • Sensing
Submission                      Slide 10      ETRI, France Telecom, Philips, Samsung
January 2006                                                           doc.: IEEE 802.22-06/0005r1

                                 WRAN Hierarchy
                                             Public IP Network



                            SD




                                         Service Provider IP Network

                        AAA                                                          HA




                                 ACR                                         ACR




         집




       CPE           WRAN                                                                            집


                      BS



                                  집                                      집




• AAA : Authentication, Authorization and Account Server
• ACR : Access Control Router HA : Home Agent

Submission                                         Slide 11                  ETRI, France Telecom, Philips, Samsung
        January 2006                                                                                                                  doc.: IEEE 802.22-06/0005r1

                                                       Deployment Scenario
                                        집




                                                                                                                                집


                                                                                       집




                집

                                                  WRAN
                    집
                                                Base Station
    집                                                                          집




                                                                                                                   집




                                                                                                                   Wireless
                                                                                                                    MIC
                                                집                          집



                                                               집                                                                                           집

                                                                                                                                                   집




                                                                                                                                                                   집




                                    집


            집
                                                                                                                                                           집

                                                                                                                                             집



                                                          TV Transmitter
                            집                                                                                            WRAN
                                                                                                                       Base Station                                                            집




                                집


                        집




                                                                                                                                         집                             집



                                                                                                                                                        WRAN
                                                                                                                                                       Repeater                        집



                                            집




                                                                                                                                      Typical ~33km                                                    집




                           Wireless                                집
                                                                                                                                      Max. 100km
                            MIC                                                                                                                                            집
                                                                                                                                                                               집           집




        : WRAN Base Station
                                                                                           집           집



                                                                                                                   집
                                                                       집



                                                                                                                                                                                   집


                                                                                                                                                                                                   집
                                                                                   집               집
                                                                                                           집




집
        : CPE                                                                                                                                                  집



                                                                                               집


                                                                                                               집




        Submission                                                                                     Slide 12                              ETRI, France Telecom, Philips, Samsung
 January 2006                                           doc.: IEEE 802.22-06/0005r1


                            PHY Overview

• OFDMA both in uplink and downlink
• QPSK, 16-QAM, and 64-QAM, spreaded-QPSK
    – OQAM is also being considered, but it has been submitted as a separate
      contribution
• More than 30 sub channels per TV channel
• Contiguous channel bonding upto 3 TV channels (and beyond in a
  stack manner)
• Data rate range from 5Mbps to 70Mbps
• TDD, FDD

                                                                          Modulation
    Randomizer               FEC                   Interleaver           (constellation
                                                                           mapping)


 Submission                             Slide 13            ETRI, France Telecom, Philips, Samsung
January 2006                              doc.: IEEE 802.22-06/0005r1


               What We Have Proposed ….

      Adaptive           Known and proven technology
      OFDMA              for broadband fixed/mobile wireless access
                         (e.g., IEEE 802.16d/e – WiBro in Korea)
         •   Adaptively scalable to spectrum availability
         •   New frame structure for CR-enabled operation
         •   Enhanced PHY features
           - Adaptive sub-carrier allocation
           - Adaptive pilot insertion
           - Enhanced channel coding (e.g., LDPC or Turbo Code)
           - Multiple antenna system
         • channel bonding
Submission                     Slide 14      ETRI, France Telecom, Philips, Samsung
January 2006                                       doc.: IEEE 802.22-06/0005r1

  Advantages of Adaptive OFDMA Proposal

 • Flexible Bandwidth Allocation
       – To use the partial bandwidth (1, 2, 3, 4, 5, 6, 7, 8 MHz) adaptively,
         depending on the channel state information (availability)
       – To fully utilize available bandwidth under a unified PHY framework


 • Single Sampling Frequency
       – Sampling frequency is the same for all FFT modes.


 • Constant Subcarrier Spacing
       – The subcarrier spacing is constant for all different channel
         bandwidths  Robust to the frequency offset

Submission                            Slide 15        ETRI, France Telecom, Philips, Samsung
       January 2006                                                                      doc.: IEEE 802.22-06/0005r1

                      PHY (Baseband) Architecture


                                                   Preamble                                                                         Binary
                                                                                               Puncturer
                               Guard                   &        Subcarrier                                                           Data
                    P/S                     IFFT                               S/P   Mapper        &        Encoder   Randomizer
                             Insertion               Pilot       Allocator
                                                                                              Interleaver
                                                   Insertion



          Channel




AWGN


                                                                                                  De-                              Recovered
                              Guard                 Channel     Subcarrier            De-     interleaver                 De-        Data
                    S/P                     FFT                                P/S                          Decoder
                             Removal               Estimation   Deallocator          mapper        &                  randomizer
                                                                                              Depuncturer




                          Synchronization




       Submission                                                   Slide 16                  ETRI, France Telecom, Philips, Samsung
  January 2006                                                         doc.: IEEE 802.22-06/0005r1

                      System Parameters: Proposed
    Parameters                            Specification                                    Remark

Frequency range        54~862 MHz
Service coverage       Typical range 33 km,
                       • Mandatory: 6, 7, 8 MHz with channel bonding         Allows the fractional use of TV
Bandwidth                                                                    channel and channel bonding up
                       • Optional: fraction BW                               to 3 TV channels
                       • Maximum: 70 Mbps                                    Maximum of 23 Mbps for 6 MHz
Data rate
                       • Minimum: 4.5 Mbps
                       • Maximum: 3.94 bits/s/Hz
Spectral Efficiency                                                          Single TV channel BW of 6 MHz
                       • Minimum: 0.75 bits/s/Hz
Modulation             QPSK, 16QAM, 64QAM
Transmit power         Default 4W EIRP
Multiple Access        Adaptive OFDMA                                        Partial bandwidth allocation
FFT Mode               1024, 2048, 4096, 6144
Cyclic Prefix Mode     1/4, 1/8, 1/16, 1/32
Duplex                 TDD or FDD
Network topology       Point-to-Multipoint Network



  Submission                                         Slide 17             ETRI, France Telecom, Philips, Samsung
January 2006                                                 doc.: IEEE 802.22-06/0005r1


                 Channel Bonding: Motivation

 • Spectrum occupancy measurements conducted by Shared
   Spectrum Company from January/2004 to August/2005 have
   shown that:
             • “There is a significant amount of spectrum available in continuous blocks that
               are 1 MHz and wider ”
             • “A dynamic spectrum sharing radio with a low agility, contiguous waveform
               will provide high utility”

 • The November 18, 2005, study from Freepress and New America
   Foundation (entitled “Measuring the TV “White Space” Available
   for Unlicensed Use”) reveals that there exists a considerable
   amount of contiguous vacant TV channels (especially in the upper
   UHF band)

 • More can be expected in other countries
Submission                                   Slide 18             ETRI, France Telecom, Philips, Samsung
January 2006                                 doc.: IEEE 802.22-06/0005r1


         Contiguous open spectrum available!
      Example: Jackson, Mississippi




Source: “Measuring the TV ‘White Space’ Available for Unlicensed
  Wireless Broadband”, Nov 18, 2005, New America Foundation
Submission                        Slide 19      ETRI, France Telecom, Philips, Samsung
January 2006                                                 doc.: IEEE 802.22-06/0005r1


                              Channel Bonding
 • Make opportunistic and simultaneous use of multiple contiguous
   TV channels

 • Benefits:
       – More data rate or range
             • Initial link-budget analysis showed that single-TV channel can not support full
               data rate (e.g., 18Mbps) upto 30 Km range


       – Multi-path Diversity
             • Small BW signal can have deep fade or flat fade
             • Wider-bandwidth signal provides more frequency/multipath diversity


       – Interference
             • Wider-band reduces the amount of interference
Submission                                    Slide 20            ETRI, France Telecom, Philips, Samsung
January 2006                                          doc.: IEEE 802.22-06/0005r1


                Channel Bonding: Capacity

 • Aggregate TV channels to get more capacity
       – Shannon: C = B.log2(1+S/N)
       – capacity proportional to BW, but logarithmic with SNR or signal
         power

 • If S/N is fixed, then capacity increases linearly with
   bandwidth

 • If signal power is fixed, but bandwidth is increased
       – C = B.log2(1+S/(BNo))
       – Capacity still increases as bandwidth is increased


Submission                              Slide 21          ETRI, France Telecom, Philips, Samsung
January 2006                    doc.: IEEE 802.22-06/0005r1
  Capacity of aggregated channels as a given
  signal power is spread over more channels




Submission           Slide 22      ETRI, France Telecom, Philips, Samsung
January 2006                                                  doc.: IEEE 802.22-06/0005r1


                  Channel Bonding Scheme
 • 6, 12, 18 MHz channels

 • Constant inter-carrier                               TV
                                                                                     TV


   spacing                                                            WRAN
                                                  N-3   N-2    N-1      N      N+1   N+2   N+3   N+4




 • Depends on availability
                                                        TV
                                                                                            TV




 • Several receiver techniques to                 N-3   N-2    N-1      N
                                                                            WRAN
                                                                               N+1   N+2   N+3   N+4

   deal with flexible BW
       – Selectable analog filters
                                                  TV

       – Up sampling digital filters
                                                                                            TV



                                                                       WAN
                                                  N-3   N-2    N-1      N      N+1   N+2   N+3   N+4




Submission                             Slide 23                      ETRI, France Telecom, Philips, Samsung
January 2006                                              doc.: IEEE 802.22-06/0005r1


                  Channel bonding structure
 • 6K FFT over 3 TV channels                      • Fixed inter-carrier spacing
       – 2K per TV channel                            – Several implementation
       – Null out the outer carriers for 1              possibilities
         or 2 TV channels

                                                                                          Data
                                             DC
                                                                                        Sub-carrier
                                           MHz
                                         6 6 MHz
                                                                                          Pilot
                                                                                        Sub-carrier

                                             DC
                                                                                        Guard/Null
                                                                                        Sub-carrier
                                         12 MHz
                                          12 MHz




                                             DC

                                         18 MHz
                                          18 MHz


Submission                               Slide 24            ETRI, France Telecom, Philips, Samsung
January 2006                                           doc.: IEEE 802.22-06/0005r1

                 FFT Mode for WRAN Systems

                        No. of Bonded Channel
                                                  1          2           3
             Basic FFT Mode


                              1K                  1K        2K          NA


                              2K                  2K        4K          6K


                              4K                  4K        NA          NA


                              6K                  6K        NA          NA




Submission                             Slide 25           ETRI, France Telecom, Philips, Samsung
January 2006                                                                                               doc.: IEEE 802.22-06/0005r1


                                           Superframe Structure
                                                                                                                                        Time
   ...                 Superframe n-1                      Superframe n                              Superframe n+1               ...




         Preamble    SCH                 frame 0                           frame 1                   ...              frame m




                                                                            Occupied by Incumbent


                                                                                                    Occupied by Incumbent


               TV Channel
                          Preamble SCH
                   t-1
   Frequency




                                                                 Frame
               TV Channel                  Frame   Frame                      Frame
                          Preamble SCH                     ...    m-2                               Preamble SCH
                   t                         0       1                         m-1
                                                                 (Quiet)                 Frame
                                                                                                                   ... Frame    Frame          Frame
                                                                                           m                            0         1              n
               TV Channel
                          Preamble SCH                                                              Preamble SCH
                   t+1




                                                                            Occupied by Incumbent




                                                                                                                                               Time
Submission                                                                 Slide 26                            ETRI, France Telecom, Philips, Samsung
  January 2006                                                doc.: IEEE 802.22-06/0005r1


                                       Preamble
   • Superframe preamble
         –     Over 1512 sub-carriers (every fourth or second non-zero),
         –     5 MHz BW
         –     Simply duplicate for additional TV channels
         –     1 MHz gap between adjacent channels to relax filtering
         –     2 symbol duration (1 more for data)
   • Frame preamble: 1-3 TV channels
         – 1728*N sub-carriers
         – Short preamble is optional

Example structure
 ST1           ST2    ST3      ST4      ST5              GI        LT1                       LT2


                             (short)                                             (long)
  Submission          TSYM                    Slide 27
                                                                          TSYM
                                                                 ETRI, France Telecom, Philips, Samsung
January 2006                          doc.: IEEE 802.22-06/0005r1

                       Preamble
 • Preamble has the repetition pattern in the time domain:
    – Time synchronization
    – Frequency synchronization
    – Channel estimation
    – Cell ID detection



 • Preamble is modulated using a boosted BPSK modulation




Submission                 Slide 28      ETRI, France Telecom, Philips, Samsung
January 2006                                            doc.: IEEE 802.22-06/0005r1


                   Spreaded QPSK/OFDMA
 • Spread data over some sub-
   carriers (QPSK only)
       – Hadamard
       – Two-carrier
       – FFT based unitary pre-coding
 •    Depending on the receiver                              Time (in OFDM symbol unit)
      structure, this can
       – Increase capturing of multipath
         diversity                                1     dev 1
                                                                          Dev2 (16QAM)
                                      subchannels 2   (64QAM)                                     Dev8
       – Increase resiliency                      3                                             (64QAM)
         to interferers                               dev3        Dev4 (S-QPSK)
                                                  4
 •    Receiver structure                                 dev5 (16QAM)
       – MMSE                                                                         Dev7 (S-QPSK)
       – Approximate ML                                  dev6 (64QAM)



Submission                               Slide 29                ETRI, France Telecom, Philips, Samsung
January 2006                                                   doc.: IEEE 802.22-06/0005r1

                 Fractional Bandwidth Usage
   •
   • If wireless microphones are in operation in TV channel, the WRAN
     systems may be clear the entire TV channel
   • The number of used sub-carriers is proportional to the fractional
     bandwidth
   • More details in this coming March meeting
   • Example:
                                  Incumbent or other CR user
             TV channel            (except microphone user)              Microphone user




                                                                                                f

             6 MHz        6 MHz                          Unused(6 MHz)
                                        Fractional use
                                        of TV channel

Submission                                   Slide 30              ETRI, France Telecom, Philips, Samsung
    January 2006                                                   doc.: IEEE 802.22-06/0005r1


                   Preliminary Link Budget (LOS)
modulation                  QPSK      64-QAM        16-QAM
coding rate                     1/2        2/3           1/2
Throughput/channel                5         19            29     Mb/s
center frequency                0.7        0.7           0.7     GHz
bandwidth                         6          6            18     MHz
Distance                      30000       6000         30000     m                     • Difficult to
Tx power                          4          4             4     W
Tx averg power                 36.0       36.0          36.0     dBm                   achieve 19Mbps
TX antenna gain                 0.0        0.0           0.0     dBi                   over 30Km
Rx power
free space path loss            119         105            119   dB
Rx antenna gain                  12          12             12   dBi
cable and other losses            3           3              3   dB
Total received avrg power       -74         -60            -74   dBm                   • channel bonding
Receiver noise figure             4           4              4   dB
Noise power                    -106        -106           -101   dBm
                                                                                       needed to achieve
Interference allowance            3           3              3   dB                    long range
Received SNR                     25          39             21   dB
Required SNR                      4          25             10   dB
Implementation/OFDM loss        6.0         6.0            6.0   dB
Link Margin                    15.4         8.3            4.6   dB




    Submission                                 Slide 31                 ETRI, France Telecom, Philips, Samsung
January 2006                        doc.: IEEE 802.22-06/0005r1
        Spectrum of the signal (before further
                      filtering)

                                                         Produced using a
                                                             6K FFT
                                                          for a single TV
                                                             channel




Submission               Slide 32      ETRI, France Telecom, Philips, Samsung
                                      January 2006                                                  doc.: IEEE 802.22-06/0005r1


                                                802.22 proposed relative RF emission
                                                               Proposed Relative RF Emission Mask
                                                                      (Output filter requirement)


                                        0

                                       -10                                                                              Mask w ith TPC cap
                                                                                                                        Part 15.209a at min. dist.
Required Out-of-band Rejection (dB)




                                       -20                                                                              Proposed Base RF Mask
                                                                                                                        Equivalent 1stAdj. Ch.
                                       -30

                                       -40

                                       -50

                                       -60

                                       -70

                                       -80

                                       -90

                                      -100
                                          -20      -15   -10         -5              0              5            10             15                   20

                                                                            Channel Spacing

                                      Submission                              Slide 33                  ETRI, France Telecom, Philips, Samsung
  January 2006                                                       doc.: IEEE 802.22-06/0005r1

        OFDMA Parameters/Single Channel (6MHz)
              Mode                    1K                     2K                  4K                     6K

         FFT Size                    1024                2048                   4096                  6144
        Bandwidth
                                                                    k MHz
      (k = 1, 2, …, 6)
     Sampling Factor                                                 8/7
   No. of Used Subcarriers
                                    140 * k             280 * k                560 * k               840 * k
(including pilot, but not DC)
   Sampling Frequency                                              48/7 MHz
    Subcarrier Spacing           6.696 kHz(***)       3.348 kHz               1.674 kHz             1.116 kHz
   Occupied Bandwidth           6.696 kHz*140*k   3.348 kHz*280*k       1.674 kHz*560*k         1.116 kHz*840*k
  Bandwidth Efficiency(*)                                          93~94 %
         FFT Time                  149.33 us           298.66 us              597.33 us               896 us
   Cyclic Prefix Time(**)          37.33 us            74.66 us               149.33 us               224 us
  OFDMA Symbol Time                186.66 us           373.33 us              746.66 us              1120 us

 (*) Bandwidth Efficiency = Subcarrier Spacing * (Number of Used Subcarriers + 1)/BW
 (**) It is assumed that cyclic prefix mode is 1/4.
 (***) Italics indicate an approximated value.
 Submission                                       Slide 34                  ETRI, France Telecom, Philips, Samsung
   January 2006                                                                doc.: IEEE 802.22-06/0005r1


         OFDMA parameters – channel bonding
                                         3 TV bands                       2 TV bands                       1 TV bands
        Parameter
                                 18         21         24           12         14          16        6          7          8
   Inter-carrier spacing,
                                3348       3906       4464         3348       3906       4464      3348       3906      4464
          DF (Hz)
   FFT period, TFFT (ms)        298.66     256.00     224.00   298.66        256.00     224.00    298.66     256.00     224.00
 Total no. of sub-carriers,
                                           6144                               4096                            2048
            NFFT
No. of guard sub-carriers,
                                   1104 (552,1,551)                      736 (368,1,367)                 368 (184,1,183)
      NG (L, DC, R)
 No. of used sub-carriers,
                                           5040                               3360                            1680
       NT = ND + NP
No. of data sub-carriers, ND               4680                               3120                            1560

No. of pilot sub-carriers, NP               360                               240                             120

Occupied bandwidth (MHz)        16.884     19.698     22.512   11.256        13.132     15.008     5.628     6.566      7.504

Bandwidth Efficiency (%)                                                      93.8

   Submission                                           Slide 37                      ETRI, France Telecom, Philips, Samsung
January 2006                                                      doc.: IEEE 802.22-06/0005r1


                                        Data Rate
 •     Bandwidth = 6 MHz
 •     FFT size = 2048
 •     Cyclic prefix mode = 1/4
 •     No pilot, no quiet periods assumed

                                                                                                Unit: Mbps
                  Code Rate
                                     7/8            5/6            3/4              2/3             1/2
     Modulation
             64QAM                  23.63          22.50         20.25             18.00           13.50

             16QAM                  15.75          15.00         13.50             12.00            9.00

             QPSK                   7.88           7.50           6.75              6.00            4.50

  Data Rate = No. of used subcarriers * code rate * no. of bits per modulation symbol/OFDM symbol time




Submission                                       Slide 38                ETRI, France Telecom, Philips, Samsung
January 2006                                                      doc.: IEEE 802.22-06/0005r1


                  Data Rate – Channel Bonding
 •     Bandwidth = 3*6 MHz
 •     FFT size = 2048
 •     Cyclic prefix mode = 1/4
 •     No pilot, no quiet periods assumed

                                                                                                Unit: Mbps
                  Code Rate
                                     7/8            5/6            3/4              2/3             1/2
     Modulation
             64QAM                  70.89          67.50         60.75             54.00           40.50

             16QAM                  47.25          45.00         40.50             36.00           27.00

             QPSK                   23.64          22.50         20.25             18.00           13.50

  Data Rate = No. of used subcarriers * code rate * no. of bits per modulation symbol/OFDM symbol time
            * no. of channel bonded


Submission                                       Slide 39                ETRI, France Telecom, Philips, Samsung
January 2006                                                     doc.: IEEE 802.22-06/0005r1

                             Spectral Efficiency
•    Single channel bandwidth = 6 MHz
•    FFT size = 2048
•    Cyclic prefix mode = 1/4
•    No pilot, no quiet periods assumed
•    The spectral efficiency is same for all fractional BW mode
                                                                                            Unit : bps/Hz
                 Code Rate
                                    7/8           5/6            3/4             2/3              1/2
    Modulation
             64QAM                 3.94           3.75          3.38             3.00            2.25

             16QAM                 2.63           2.50          2.25             2.00            1.50
             QPSK                  1.31           1.25          1.13             1.00            0.75
Spectral Efficiency = No. of used subcarrier*code rate*no. of bits per modulation symbol/OFDM symbol time/BW



Submission                                      Slide 40               ETRI, France Telecom, Philips, Samsung
January 2006                                                                doc.: IEEE 802.22-06/0005r1

         Minimum Peak Throughput per CPE
•    Bandwidth = 6 MHz
•    FFT size = 2048
•    Cyclic prefix mode = 1/4
•    No. of CPE’s = 512 CPE’s/oversubscription ratio 50 ~ 11 CPE’s
•    No pilot, no quiet periods assumed
                                                                                                        Unit : Mbps
                  Code Rate
                                         7/8              5/6              3/4              2/3             1/2
    Modulation
             64QAM                      2.15             2.05             1.84             1.64             1.23

             16QAM                      1.43             1.36             1.23             1.09             0.82

             QPSK                       0.72             0.68             0.61             0.55             0.41
Min. Peak Throughput = No. of used subcarriers*code rate*no. of bits per modulation symbol/OFDM symbol time/no. of CPE’s



Submission                                              Slide 41                 ETRI, France Telecom, Philips, Samsung
January 2006                                                   doc.: IEEE 802.22-06/0005r1

                             Subchannelization
                            Subcarrier Allocation

     Uniformly Distributed                        Adjacent
     Subcarrier permutation                 Subcarrier Permutation

                                    Band type                                    Scattered type
                              BIN                                          BIN
                                                                Band #1
                  Band #1
                                                                Band #2

                                                                Band #3
                  Band #2
                                                                Band #4

                                                                Band #5
                  Band #3                            …                                                    …
                                                                                                              User 0


                                                      User 0                                                  User 1




                                                                   …
                    …




                                                      User 1                                                  User 2


                 Band #24                             User 2                                                  User 3
                                                                Band #48

                                                     Symbol                                               Symbol




Submission                                Slide 42                   ETRI, France Telecom, Philips, Samsung
 January 2006                                                doc.: IEEE 802.22-06/0005r1


                      Subchannelization (cont.)

• Type of subchannelization is determined by channel quality information
                    Adjacent                                    Distributed
              Subcarrier Permutation                       Subcarrier permutation
        • Each subchannel consists of a                 • Each subchannel consists of
           group of adjacent subcarriers                  distributed subcarriers within an
        • Bands in good state are selected                OFDM symbol
           for data transmission                        • Only the average CINR over all
        • Multiuser diversity                             subcarriers is required
        • Require more feedback                         • For users with high frequency
          information than distributed                    selectivity or far distant users
          subcarrier allocation type




 Submission                                  Slide 43             ETRI, France Telecom, Philips, Samsung
January 2006                                          doc.: IEEE 802.22-06/0005r1

                 Subchannelization (cont.)
• Band-Type Adjacent Subcarrier Allocation
     – To achieve the multi-user diversity gain
     – Multiple bins allocated to each user
       (Bin denotes a group of adjacent subcarriers).
                                                BIN


                                     Band #1



                                     Band #2



                                     Band #3                                             …


                                                                                          User 0
                                        …




                                                                                          User 1

                                     Band #24                                             User 2



                                                                                         Symbol



Submission                          Slide 44             ETRI, France Telecom, Philips, Samsung
January 2006                                          doc.: IEEE 802.22-06/0005r1

                 Subchannelization (cont.)
• Scattered-Type Adjacent Subcarrier Allocation
     – To achieve the multi-user diversity gain
     – Only one bin allocated to each user

                                                BIN
                                      Band #1

                                      Band #2

                                      Band #3

                                      Band #4

                                      Band #5
                                                                                          …
                                                                                           User 0


                                                                                           User 1
                                         …



                                                                                           User 2


                                                                                           User 3
                                     Band #48

                                                                                          Symbol




Submission                          Slide 45             ETRI, France Telecom, Philips, Samsung
January 2006                                               doc.: IEEE 802.22-06/0005r1

                 Subchannelization (cont.)
• Distributed Subcarrier Allocation
     – Subcarriers are pseudo-randomly selected for frequency diversity




                                       Subcarriers                        Number of used subcarriers
                                  Pilot subcarriers                                        ...
                                  Data subcarriers                                         ...
                                          Groups      G0   G1        G2                 ...               GN
                                                                                        ...
                                     Subchannels      S0        S1                                        SM




Submission                           Slide 46                    ETRI, France Telecom, Philips, Samsung
January 2006                                                                                                              doc.: IEEE 802.22-06/0005r1

                                                                                           Pilot Pattern
 • Pilot pattern is varied with channel condition:
      - Adaptively rotated pilot pattern
      - Channel estimation by preamble or pilot, depending on power boosting
 • Pilot subcarriers are modulated using a boosted BPSK
   modulation
                                                                                                                                             Preamble

                                                                                                                                            Boosted Pilot
                                                       Pilot Period(variable)
                                                              Pilot Period(variable)
                                               Pilot SymbolSymbolSymbol Period(variable)         OFDMA Symbol Direction
                                                                                                                                             Data
           Pilot Subcarrier Period(variable)
         Pilot Subcarrier Period(variable)
         Subcarrier Direction
         Subcarrier Direction




Submission                                                                                      Slide 47                     ETRI, France Telecom, Philips, Samsung
January 2006                                      doc.: IEEE 802.22-06/0005r1

                    Channel Coding Scheme
 • Coding Scheme
       – Convolutional Code -> similar to the 802.16
       – Optional:
             • LDPC Code
             • Duo Binary Turbo Code
             • Concatenated code


 • Code Rates
       – CC , R = 1/2, 2/3, 3/4, 5/6, 7/8
       – LDPC, R = 1/2, 2/3, 3/4, 5/6, 7/8
       – DTC, R = 1/3, 1/2, 2/3, 3/4, 5/6, 7/8



Submission                             Slide 48      ETRI, France Telecom, Philips, Samsung
January 2006                                                 doc.: IEEE 802.22-06/0005r1

                        Channel Encoder
 • DB-CTC Encoder                                   • LDPC Encoder
       – Same to 802.16e                                          ST
                                                                                                  p1
       – Puncturing pattern and       Information bits
                                            ST
                                                                                                                         p2
         CTC interleaver are also                        A             ET-1         1       B                    T-1




         same to 802.16e
                                                             C




                                                                              H matrix
                                                                 n  m               m  p                p



                                                                  A                       B
                                                                                                       T  I   p         p




                                                                   C                      D               E              m  p




Submission                          Slide 49                           ETRI, France Telecom, Philips, Samsung
January 2006                                                                     doc.: IEEE 802.22-06/0005r1

                                 Channel Decoder
 • CTC Decoder                                                                       DEINT
                                                                          Le2 (u )
                                          2
                                            yp
                                          2 1
                       2                                   MAP
                                                                          INT
                        2                                 decoder L (u )
                                                                    e1
                                     2
              yk                          ys
                             S/P    2                                                MAP
                                                              INT                                ˆ
                                                                                                 uk
                                                                                      decoder
                                               2       p
                                                      y2
                                                 2



 • LDPC Decoder
                                                                    B
                             memQ                                                         memR
                             _even                                  B                     _even
        A
                             memQ                                   B                     memR
                             _odd                                                         _odd
                                                                    B
 A: Bit_to_Check block ; memQ(even,odd):implement a pair of message buffers alternating between R/W
 B: Check_to_Bit block ; memR(even,odd): implement a pair of message buffers alternating between R/W

Submission                                                    Slide 50               ETRI, France Telecom, Philips, Samsung
January 2006                                    doc.: IEEE 802.22-06/0005r1


                  Duo-Binary Turbo-code

 • Duo-Binary input: two decoded bit output at a time
       – Reduction of latency and complexity per decoded bit (compared to
         Binary TC)
       – Better convergence


 • Circular (tail-biting) encoding
       – No trellis termination overhead


 • Original interleaving scheme
       – Larger minimum distances
       – Improved asymptotic performances


Submission                          Slide 51       ETRI, France Telecom, Philips, Samsung
    January 2006                                           doc.: IEEE 802.22-06/0005r1


                           Internal Interleaver
•    Algorithmic permutation
        –One equation, 4 parameters (P0, P1, P2,
         P3)
                                                       i = 0, …, N-1, j = 0, ...N-1
        –Parameters selected such that interleaver
                                                       level 1: if j mod. 2 = 0, let (A,B) = (B,A) (invert the
         is contention-free                            couple)
                                                       level 2:

•    Adjusting the TC to a blocksize only              -               if j mod. 4 = 0, then P = 0;
                                                       -               if j mod. 4 = 1, then P = N/2 + P1;
     requires modification of the 4
                                                       -               if j mod. 4 = 2, then P = P2;
     parameters                                        -               if j mod. 4 = 3, then P = N/2 + P3.
                                                       i = P0*j + P +1 mod. N

•    Quasi-regular permutation (easy
     connectivity)

•    Inherent parallelism
    Submission                              Slide 52              ETRI, France Telecom, Philips, Samsung
January 2006                                          doc.: IEEE 802.22-06/0005r1


                                   Flexibility
•      Can be easily adjusted to any blocksize
             –Storage of the 4 parameters for all blocksizes considered
             –Possibility of a generic approach (default parameters)
•      All coding rates are possible
             –Through puncturing patterns
             –Natural coding rate is ½: increased robustness to puncturing
•      Performance vs complexity: several adjustments are
       possible
             –Number of iterations, Decoding algorithm, …
•      Implementation: interleaver enables different degrees
       of parallelism
             –Can be adjusted to meet complexity/throughput requirements


Submission                                Slide 53        ETRI, France Telecom, Philips, Samsung
January 2006                                     doc.: IEEE 802.22-06/0005r1


      Advantages of Duo-binary Turbo-codes

 • Good performance for a very wide range of blocksizes

 • Highly flexible scheme, enabling a very fine granularity
       – Same encoder/decoder for all blocksizes/coding rates.
       – Several trade-off in performance (number of iterations, decoding
         algorithm), implementation complexity (degrees of parallelism).


 • Reasonable complexity
       – Approximately 35% decrease in complexity per decoded bit
         compared to Binary TC.



Submission                           Slide 54        ETRI, France Telecom, Philips, Samsung
January 2006                                   doc.: IEEE 802.22-06/0005r1


                           State of the art

 • Duo-binary Turbo-code is a mature technology

 • This technology has already been selected by several
   standardization groups
       –     IEEE 802.16 / WiMAX;
       –     DVB-RCS;
       –     DVB-RCT;
       –     ETSI HIPERMAN




Submission                          Slide 55      ETRI, France Telecom, Philips, Samsung
January 2006                           doc.: IEEE 802.22-06/0005r1
                     Summary:
               Gains brought by DTC

 • Duo-binary TC offers 3.5 to 4 dB over CC

 • When combined the gain is at least 4.5 dB that allows
   to increase the radius by 7.6 km (17%) with QPSK
   modulation in a Gaussian channel.




Submission                  Slide 56      ETRI, France Telecom, Philips, Samsung
January 2006                          doc.: IEEE 802.22-06/0005r1
     Multiple Antenna Techniques for 802.22
                    Systems

• Transmit Diversity Techniques
• Adaptive Beam-Forming Techniques
• Feasibility of the two techniques in 802.22 environments
  will be investigated.




Submission                 Slide 57      ETRI, France Telecom, Philips, Samsung
January 2006                                         doc.: IEEE 802.22-06/0005r1
     Multiple Antenna Techniques for 802.22
        Systems : Transmit Diversity (1)
 • Advantages of Transmit Diversity
       –     Easily increases spectral efficiency by utilizing diversity gain
       –     Simple detection algorithm unlike spatial multiplexing schemes
       –     No limit on the number of Rx antennas ==> highly flexible
       –     No substantial increase in hardware complexity in both CPE and
             BS: the same antennas for receive diversity at BS can be used.

 • Open Loop: STC
       – Orthogonal code algorithms: Alamouti’s scheme (2Tx), Tarokh’s
         scheme (3, 4Tx)
       – Quasi-orthogonal code algorithm (4Tx)
       – STTC, etc.


Submission                              Slide 58        ETRI, France Telecom, Philips, Samsung
January 2006                                   doc.: IEEE 802.22-06/0005r1
     Multiple Antenna Techniques for 802.22
        Systems : Transmit Diversity (2)
 • Closed Loop:
       – Most effective in fixed environments
       – Eigen-beamforming at base-station: best performance, however
         requires down-link channel information at transmitter.
       – Reduced-feedback methods: number of feedback bits can be
         reduced, with ~ 1dB performance loss
       – No feedback from the CPE for TDD due to reciprocity property

 • Considering the spectrum bands to be used for 802.22
   systems, transmit diversity with two antennas seems
   most applicable.


Submission                         Slide 59       ETRI, France Telecom, Philips, Samsung
January 2006                                                   doc.: IEEE 802.22-06/0005r1


                         STBC-OFDM System


                                                        IFFT         Cyclic prefix             h 1~ 4
         Binary      Data              STBC
       input data   mapping
                                S/P
                                      Encoding                     Cyclic prefix
                                                                                   
                                                        IFFT




                Cyclic
                                       Linear                         Data             Binary
                prefix        FFT                       P/S
                                      Combiner                      demapping        output data
               Removal




                    Figure. Block diagram of an STBC-OFDM system


Submission                               Slide 60                    ETRI, France Telecom, Philips, Samsung
January 2006                                     doc.: IEEE 802.22-06/0005r1

        Performance Evaluation : Simulation
                   Conditions
 •    Two Tx antennas
 •    2K mode system used for simulation
 •    Delay profiles defined for 802.22
 •    Fixed Doppler spectrum defined for 802.16a
 •    Channel estimation
       – Partitioned MMSE estimation performed by using the preamble
       – SNR in MMSE: 20dB
       – RMS delay parameter in MMSE: 9ms
 • Others
       – Two OFDM symbols used for forward link preamble
       – Preamble symbol strength set to the average signal strength
       – No channel coding employed

Submission                           Slide 61        ETRI, France Telecom, Philips, Samsung
January 2006                                                                  doc.: IEEE 802.22-06/0005r1

                     Performance Evaluation : STBC (1)
                          0
                     10
                                                                              Modulation = QPSK
                                                                              No. of Rx Ant = 1
                                                                              r = 0.7

                      -1
                     10
       Uncoded BER




                      -2
                     10

                                                                                                   Performance gain:
                      -3
                     10           Alamouti case
                                                                                                    3.7dB ~ 7.5dB at
                                        Profile A                                                   10-2 ~ 10-3 BER
                                        Profile B
                                        Profile C
                                        Profile D
                      -4          No diversity case
                     10
                                        Profile A
                                        Profile B
                                        Profile C
                                        Profile D
                      -5
                     10
                              0                  5    10      15         20           25
                                                           Eb/No
     Figure. BER performance of Alamouti’s scheme in 802.22 environments
                     (QPSK, degree of correlation r = 0.7)
Submission                                                    Slide 62              ETRI, France Telecom, Philips, Samsung
January 2006                                                                   doc.: IEEE 802.22-06/0005r1

                     Performance Evaluation : STBC (2)
                          0
                     10
                                                                              Modulation = 16QAM
                                                                              No. of Rx Ant = 1
                                                                              r = 0.7

                      -1
                     10
       Uncoded BER




                      -2
                     10
                                                                                                    Performance gain:
                      -3
                                                                                                     3.4dB ~ 7.0dB at
                     10           Alamouti case                                                       10-2 ~ 10-3 BER
                                        Profile A
                                        Profile B
                                        Profile C
                                        Profile D
                      -4
                     10           No diversity case
                                        Profile A
                                        Profile B
                                        Profile C
                                        Profile D
                      -5
                     10
                              0                  5    10      15         20            25
                                                           Eb/No

    Figure. BER performance of Alamouti’s scheme in 802.22 environments
                   (16QAM, degree of correlation r = 0.7)
Submission                                                    Slide 63                ETRI, France Telecom, Philips, Samsung
January 2006                                                                  doc.: IEEE 802.22-06/0005r1

                  Performance Evaluation : STBC (3)
                           0
                      10
                                                                              Modulation = 64QAM
                                                                              No. of Rx Ant = 1
                                                                              r = 0.7

                       -1
                      10
        Uncoded BER




                       -2
                      10

                                                                                                   Performance gain:
                       -3                                                                           3.1dB ~ 6.0dB at
                      10           Alamouti case
                                         Profile A                                                   10-2 ~ 10-3 BER
                                         Profile B
                                         Profile C
                                         Profile D
                       -4
                      10           No diversity case
                                         Profile A
                                         Profile B
                                         Profile C
                                         Profile D
                       -5
                      10
                               0                  5    10      15        20            25
                                                            Eb/No
    Figure. BER performance of Alamouti’s scheme in 802.22 environments
                   (64QAM, degree of correlation r = 0.7)
Submission                                                    Slide 64              ETRI, France Telecom, Philips, Samsung
January 2006                                                                            doc.: IEEE 802.22-06/0005r1

             Performance Evaluation : STBC (4)
                                 0
                            10
                                                                                                 Modulation = QPSK
                                                                                                 No. of Rx Ant = 1


                             -1
                            10
              Uncoded BER




                             -2
                            10



                             -3
                            10


                                               No diversity case
                             -4
                            10           Alamoti case(Profile A)
                                               Correlation = 0.0
                                               Correlation = 0.4
                                               Correlation = 0.7
                                               Correlation = 0.9
                             -5
                            10
                                     0                 5           10              15    20              25
                                                                           Eb/No

      Figure. BER performance vs. degree of correlation in 802.22 environments
                                (Profile A, QPSK)
Submission                                                              Slide 65              ETRI, France Telecom, Philips, Samsung
January 2006                         doc.: IEEE 802.22-06/0005r1


             Transmit Diversity Performance




Submission                Slide 66      ETRI, France Telecom, Philips, Samsung
January 2006                                                                            doc.: IEEE 802.22-06/0005r1

     Degree of Correlation vs. Antenna Separation
                                     1.0

                                     0.9
                                                                                                              o
                                                                                        Angular spread = 0.5
                                     0.8
             Degree of Correlation




                                     0.7

                                     0.6
                                                                                                         o
                                                                                     Angular spread = 1
                                     0.5

                                     0.4

                                     0.3                                                            o
                                                                              Angular spread = 2
                                     0.2
                                                                                         o
                                                                      Angular spread = 4
                                     0.1

                                     0.0
                                           0   2   4    6      8        10      12           14     16       18    20
                                                       Antenna Separation (wavelengths)

             Figure. Degree of correlation vs. antenna separation for various
                          angular spreads (Laplacian model)
Submission                                                         Slide 67                       ETRI, France Telecom, Philips, Samsung
January 2006                          doc.: IEEE 802.22-06/0005r1


             Summary : Transmit Diversity

 • About 3 –7dB downlink gain with 2 transmit antennas
   for r=0.7, when employing open loop transmit diversity.
 • Additional 2.0 –2.5dB gain for r=0.7, when employing
   closed loop transmit diversity.
 • Even in a highly correlated case of r=0.9, the
   performance improvement is rather acceptable.




Submission                 Slide 68      ETRI, France Telecom, Philips, Samsung
January 2006                                       doc.: IEEE 802.22-06/0005r1


             Open Issues : Transmit Diversity
 • Does sufficient diversity always exist to realize the
   gains?
       – Further investigation is necessary but seems obtainable for higher
         frequency bands!
       – The angular spread due to local scattering will be less than 0.5o in
         802.22 environments.
       – However, the scattering due to remote objects may increase the
         angular spread, which in turn decreases the degree of correlation.
       – Selective usage according to the spectrum band will be necessary.

 • Signaling format and pilot patterns to allow transmit
   diversity options need to be specified at very start of
   standardization process.

Submission                            Slide 69        ETRI, France Telecom, Philips, Samsung
January 2006                                      doc.: IEEE 802.22-06/0005r1
     Multiple Antenna Techniques for 802.22
     Systems : Adaptive Beam-Forming (1)
 • Why adaptive beam-forming for 802.22 systems?
       – Adaptive beam-forming can mitigate the effect of co-channel
         interference (CCI) inherent to OFDMA systems, thereby
         increasing frequency reuse factor close to unity.
       – Since all CPEs are fixed at known locations, their directions-of-
         arrival (DOAs) may easily be obtained and incorporated for
         adaptive beam-forming without need to be tracked.
       – Large cell in 802.22 networks also makes beam-forming problem
         simple from 2D to 1D problem: easy DOA estimation (if
         necessary) or beam-forming using an array with simple
         configuration.
       – In conjunction with the transmit diversity in the forward link
         and/or receive diversity in the reverse link, adaptive beam-forming
         may significantly increase cell radius, as required for 802.22
         systems.
Submission                           Slide 70        ETRI, France Telecom, Philips, Samsung
January 2006                                                    doc.: IEEE 802.22-06/0005r1
     Multiple Antenna Techniques for 802.22
     Systems : Adaptive Beam-Forming (2)
 • Adaptive array vs. Fixed-beam array
       – More Efficient CCI Suppression: Adaptive array system steers the
         main beam to the direction of a desired signal, while steering nulls
         to the directions of undesired signals.
                                    1st co-channel interferer




                                        desired signal




                   fixed-beam                                        adaptive array



                                    2nd co-channel interferer


                      Figure. Adaptive array vs. fixed-beam array
Submission                                Slide 71                 ETRI, France Telecom, Philips, Samsung
January 2006                                        doc.: IEEE 802.22-06/0005r1


         Adaptive Beam-Forming Algorithms

 • DOA Based Sample Matrix Inversion (SMI) Algorithm
                    w  R u 1a q 
                    ˆ ˆ

     where a q  is the steering vector for incident angle q and R u is the
                                                                  ˆ
     estimated interference-plus-noise covariance matrix.

 • Reference Signal Based SMI Algorithm
                    ˆ ˆx ˆ
                    w  R1rxd
              ˆ                               ˆ
      where rxd is the correlation vector and R x is the estimated covariance
      matrix.
       – Reference signal is required!

Submission                            Slide 72          ETRI, France Telecom, Philips, Samsung
January 2006                                              doc.: IEEE 802.22-06/0005r1

        Performance Evaluation : Simulation
                   Conditions
 • Antenna Array
       – Array type: Linear equi-spaced array with half wavelength spacing
         consisting of 8 antenna elements.
       – Root-MUSIC is used to estimate the DOAs of incident signals.
       – All incident signals are assumed to have zero elevation angle.
 • Angular Spread
       – Laplacian model
       – All clusters are assumed to have the angular spread of 0.3o.
 • Others
       –     No. of OFDM symbols for reverse link preamble is 1.
       –     No. of sub-carriers assigned to users is 256.
       –     No. of sub-carriers per sub-band is 16 for reference signal method.
       –     No channel coding employed

Submission                                  Slide 73          ETRI, France Telecom, Philips, Samsung
 January 2006                                              doc.: IEEE 802.22-06/0005r1


        Channel Parameters for Simulation (1)
                                                            (* : defined for adaptive beam-forming)

PROFILE A            Path 1    Path 2             Path 3     Path 4        Path 5         Path 6
Excess delay           0       3 msec             8 msec     11 msec       13 msec        21 msec
Relative amplitude     0       -7 dB              -15 dB     -22 dB        -24 dB         -19 dB
Doppler frequency      0       0.10 Hz            2.5 Hz     0.13 Hz      0.17 Hz        0.37 Hz
Incident angles*       0o       2.6o              -6.9o       9.5o         -11.2o          18.0o
rms delay                                             0.68 msec

PROFILE B            Path 1    Path 2             Path 3     Path 4        Path 5         Path 6
Excess delay         -3 msec     0                2 msec     4 msec        7 msec         11 msec
Relative amplitude   -6 dB       0                -7 dB      -22 dB        -16 dB         -20 dB
Doppler frequency    0.1 Hz      0            0.13 Hz        2.5 Hz       0.17 Hz        0.37 Hz
Incident angles*       0o       2.6o              -4.3o       6.0o          -8.6o          12.0o
rms delay                                             0.83 msec


 Submission                            Slide 74               ETRI, France Telecom, Philips, Samsung
 January 2006                                            doc.: IEEE 802.22-06/0005r1


        Channel Parameters for Simulation (2)
                                                            (* : defined for adaptive beam-forming)

PROFILE C            Path 1    Path 2           Path 3     Path 4       Path 5          Path 6
Excess delay         -2 msec     0              5 msec     16 msec      24 msec        33 msec
Relative amplitude   -9 dB       0              -19 dB     -14 dB       -24 dB          -16 dB
Doppler frequency    0.13 Hz     0          0.17 Hz        2.5 Hz       0.23 Hz        0.10 Hz
Incident angles*       0o      -0.86o           -3.0o       7.7o         -11.2o          15.0o
rms delay                                           1.07 msec

PROFILE D            Path 1    Path 2           Path 3     Path 4       Path 5          Path 6
Excess delay         -2 msec     0              5 msec     16 msec      22 msec        28 msec
Relative amplitude   -10 dB      0              -22 dB     -18 dB       -21 dB          -7 dB
Doppler frequency    0.23 Hz     0              0.1 Hz     2.5 Hz       0.17 Hz        0.13 Hz
Incident angles*       0o      -0.86o           -3.0o       7.7o         -10.3o          13.0o
rms delay                                           5.36 msec


 Submission                          Slide 75               ETRI, France Telecom, Philips, Samsung
January 2006                                                                           doc.: IEEE 802.22-06/0005r1

     Performance Evaluation : ABF Algorithms (1)
                                0
                           10




                            -1
                           10
             Uncoded BER




                            -2
                           10




                            -3              Single Antenna
                           10
                                        DOA Based         Reference
                                                Profile A
                                                Profile B
                                                Profile C
                            -4
                                                Profile D
                           10
                                    0              5              10              15      20           25
                                                                        SNR (dB)

         Figure. Comparison of BER performance for reverse link (INR = 25dB,
            interference DOAs =(20o, 30o), relative amplitude = (0dB, -3dB) )
Submission                                                             Slide 76           ETRI, France Telecom, Philips, Samsung
January 2006                                                                        doc.: IEEE 802.22-06/0005r1

     Performance Evaluation : ABF Algorithms (2)
                                 24


                                 22
      Average Output SINR (dB)




                                 20
                                                                                                    Perfect interference
                                 18                                                                 cancellation :
                                                                                                    Output SINR = 24dB
                                 16


                                 14
                                                                     DOA Based Algorithm
                                                                     Reference Signal Method
                                 12
                                   10   15   20      25      30     35       40     45         50
                                                  Azimuth Difference (Deg)

    Figure. Average output SINR vs. azimuth difference for reverse link ( Profile A,
             SNR = 15dB, INR = 25dB, relative amplitude = (0dB, -3dB) )
Submission                                                        Slide 77               ETRI, France Telecom, Philips, Samsung
January 2006                                                                               doc.: IEEE 802.22-06/0005r1

     Performance Evaluation : ABF Algorithms (3)
                        0
                   10




                    -1
                   10
                                                                                                        • Error distribution:
     Uncoded BER




                                                                                                          truncated Gaussian
                    -2
                   10
                                                                                                        • Ref. signal method:
                                                                                                          insensitive due to
                    -3
                                      No Errors                                                           self-healing nature
                   10                 Amp Error = 10%, Phase Error = 10
                                                                       o

                                                                       o
                                      Amp Error = 20%, Phase Error = 20
                                      Amp Error = 30%, Phase Error = 30
                                                                       o
                                                                                                        • DOA based method:
                                Dashed line : DOA Based Algorithm
                    -4
                                Solid line : Reference Signal Method                                      relatively insensitive
                   10
                            0            5              10                 15         20        25
                                                             SNR (dB)

   Figure. Channel mismatch effect for reverse link ( Profile A, INR = 25dB,
      interference DOAs = (20o, 30o), relative amplitude = (0dB, -3dB) )
Submission                                                                 Slide 78           ETRI, France Telecom, Philips, Samsung
January 2006                                                                                   doc.: IEEE 802.22-06/0005r1

     Performance Evaluation : ABF Algorithms (4)
                          0
                     10




                      -1
                     10

                                                                                                            • Error distribution:
       Uncoded BER




                                                                                                              truncated Gaussian
                      -2
                     10
                                                                                                            • Ref. signal method:
                                       No Errors                                                              extremely sensitive
                                                                           o
                      -3               Amp Error = 0.1%, Phase Error = 0.1
                     10                Amp Error = 0.2%, Phase Error = 0.2
                                                                           o


                                       Amp Error = 0.3%, Phase Error = 0.3
                                                                           o

                                                                           o
                                                                                                            • DOA based method:
                                       Amp Error = 0.5%, Phase Error = 0.5
                                  Dashed line : DOA Based Algorithm                                           relatively insensitive
                                  Solid line : Reference Signal Method
                      -4
                     10
                              0               5                10              15         20        25
                                                                    SNR (dB)

     Figure. Effect of channel mismatch for forward link ( Profile A, INR = 25dB,
          interference DOAs = (20o, 30o), relative amplitude = (0dB, -3dB) )

Submission                                                                     Slide 79           ETRI, France Telecom, Philips, Samsung
January 2006                                    doc.: IEEE 802.22-06/0005r1


         Summary : Adaptive Beam-Forming
 • Efficient CCI cancellation by simple adaptive beam-
   forming algorithms
 • In the reverse link, the reference signal method seems
   more effective due to
       – Simplicity in implementation
       – Robustness to channel mismatch or self-healing nature
       – However, in the case of a very large delay spread, the DOA based
         approach seems more preferred.
       – Selective usage may be necessary.
 • In the forward link, the DOA based method seems
   more desirable.
       – Robustness to the channel mismatch in the forward


Submission                          Slide 80        ETRI, France Telecom, Philips, Samsung
January 2006                           doc.: IEEE 802.22-06/0005r1


       Open Issues : Adaptive Beam-Forming

 • A relevant vector channel model is necessary for reliable
   performance evaluation.

 • Reverse link preamble may be necessary to differentiate
   a desired signal from CCIs, which should be considered
   at very start of standardization process.




Submission                  Slide 81      ETRI, France Telecom, Philips, Samsung
January 2006                           doc.: IEEE 802.22-06/0005r1

             Additional Physical Layer Features

 • Ranging

 • TPC




Submission                  Slide 82      ETRI, France Telecom, Philips, Samsung
January 2006                    doc.: IEEE 802.22-06/0005r1




               Spectrum Sensing




Submission           Slide 84      ETRI, France Telecom, Philips, Samsung
January 2006                       doc.: IEEE 802.22-06/0005r1


               Distributed Sensing




                         CSDU: Central Sensing Decision Unit
Submission             Slide 85        ETRI, France Telecom, Philips, Samsung
January 2006                                                           doc.: IEEE 802.22-06/0005r1


             Proposed Spectrum Sensing Scheme
 •    Dual Sensing Strategy: Energy detection and Fine/Feature detection
 •    Energy Detection
       –     To meet the speed and power requirement
       –     Power spectrum distribution in the entire band is obtained
       –     On request basis, detect the power level of selected channel in very short time
       –     Examples are MRSS, RSSI
 •    Fine/Feature Detection
       –     To meet the minimum sensitivity requirement
       –     Fine sensing is applied for the selected channel
       –     Feature Detection: detecting digital modulated signals
       –     Examples include CSFD, field-sync detection
       –     FFT based spectral analysis: detecting narrowband analog modulated signals, most of part 74
             devices
 •    Distributed Sensing Strategy : Frequency usage information is collected and
      managed at Base-station
 •    Either the BS makes the detection decision based on the collective measurement
      results or CPE’s can make the decision
 •    Can be implemented as a stand alone sensing block with an omni-directional
      antenna
Submission                                           Slide 86                ETRI, France Telecom, Philips, Samsung
January 2006                               doc.: IEEE 802.22-06/0005r1


             Spectrum Sensing Architecture

   Omni Antenna


                        Fine/Feature




                  RFE         Control        MAC




                        Energy Detection




Submission                  Slide 87          ETRI, France Telecom, Philips, Samsung
January 2006                                       doc.: IEEE 802.22-06/0005r1


                   Spectrum Sensing Strategy


             Select candidates via
               Energy Detection        •Sensing active channel during quite period
                                       •Sensing non-active/candidate/backup channels
                                       •Scanning during initial startup


             Fine/Feature detection
             for a selected channel




Submission                            Slide 88         ETRI, France Telecom, Philips, Samsung
January 2006                                           doc.: IEEE 802.22-06/0005r1


                   Energy Detection Method
 •    Received signal strength within a given bandwidth is detected after the RF
      receiver
 •    Decision can be made by many different ways
       – Analog/digital integration, MRSS, RSSI, FFT
 •    Full range of spectrum profile can be obtained quickly with low power
      consumption
 •    Integration time and threshold is very important
 •    BS sets essential parameters (constant)




                Filter     LNA                                               Decision



Submission                               Slide 89         ETRI, France Telecom, Philips, Samsung
      January 2006                                                                                              doc.: IEEE 802.22-06/0005r1


                 Cyclostationarity based signal detection

                                                                                                                           Signal attributes
                                    Sliding                                                                                –Power
                    x(n)                                                Correlate and                Feature               –Modulation
                                     N-pt
                                                                        average sum                  detector              –Symbol frequency
                                     FFT
                  N / 2 1
                                                                                      1 M / 21             mfs                 mfs 
X T ( n, f )      
                 p  N / 2
                              x ( n  p )e    j 2  f ( n  p ) / fs    
                                                                        S ( n, f ) 
                                                                         x Dt               / 2 X T (n, f  N  2 ) X T* (n, f  N  2 )
                                                                                     MN m  M


• Cyclic spectrum domain reveals signal specific features at
        – Modulating frequency
        – Carrier frequency
        – … (signal frequencies specific to modulation parameters)
• Various forms of detectors can be derived from cyclic power spectrum
  density


      Submission                                                                          Slide 90                 ETRI, France Telecom, Philips, Samsung
   January 2006                                                                doc.: IEEE 802.22-06/0005r1

                   Local detection at each CPE
• Signal detection
    – Signal x(k), that is transmitted over channel h(k), to be detected in presence of
      AWGN n(k)
                      [signal absent hypothesis] H 0 : x( k )  n( k )
                      [signal present hypothesis] H 1 : x( k )  h( k ) * s( k )  n( k )
         • h(k) is the impulse response of channel between Tx and CPE Rx
• Measure received cyclic power spectrum at specific cycle frequencies
    – Specific cycle frequencies could be VSB Nyquist frequency (5.38 MHz), WRAN
      OFDM symbol frequency (x MHz), etc.
    – Declare signal sj present if spectral component detected at corresponding cycle
      frequencies { j} (decision fusion)
                                    Sn ( f ),
                                      0
                                                                              0, signal absent
                                   
                                   | H ( f ) | S s ( f )  Sn ( f ),
                                               2  0          0
                                                                              0, signal present
                                  
                       S x ( f ) = 0,                                        0, signal absent
                                   
                                    H ( f   ) H * ( f   ) S  ( f ),     0, signal present
                                   
                                              2             2
                                                                   s



   Submission                                            Slide 91                   ETRI, France Telecom, Philips, Samsung
 January 2006                                          doc.: IEEE 802.22-06/0005r1


                  Detection algorithm modes

• Basic mode of detection algorithm
    – Detection of signal energy (from alpha = 0 spectral content)
    – Used in high SNR regimes for pilot/carrier/signature detection type schemes
    – Eg., pilot about 11 dB below at 310 KHz carrier offset from lower end frequency


• Enhanced mode of detection algorithm
    – Detection of spectral features (spectral content at signal symbol frequency,
      carrier frequency, …)
    – Used in low SNR regimes
    – Especially useful during initialization procedures where BS is looking for an
      empty channel in possibly low SNR conditions



 Submission                              Slide 92          ETRI, France Telecom, Philips, Samsung
  January 2006                                                                 doc.: IEEE 802.22-06/0005r1


        Advantages of cyclostationary detection
• Cyclic spectrum domain a richer domain for signal analysis than
  conventional power spectrum
• Robust to noise
    – Stationary noise exhibits no cyclic correlations
                     Sn ( f ),
                       0
                                                               0, signal absent
                    
                    | H ( f ) | S s ( f )  S n ( f ),
                                2  0           0
                                                               0, signal present
                   
        S x ( f ) = 0,                                        0, signal absent
                    
                     H ( f   ) H * ( f   ) S  ( f ),     0, signal present
                    
                               2             2
                                                     s




• Better detector performance even in low SNR regions
• Signal classification ability
    – Different signals have different cycle frequencies and exhibit distinct spectral
      characteristics
• Can be used as an energy detector in alpha = 0 mode
    – Flexibility of operation
  Submission                                                  Slide 93               ETRI, France Telecom, Philips, Samsung
January 2006                                     doc.: IEEE 802.22-06/0005r1
      DTV signal feature detection using field
                 sync/correlation

 • Should not be sensitive to frequency selective fading,
   and receiver impairments (e.g., frequency error)

 • Use field sync correlation detection for ATSC, similar
   correlation for other standards
       – Compare correlation peak to the mean of the standard deviation of
         the correlation

       – Characterized the theoretical performance
       – Experimental tests

Submission                          Slide 94         ETRI, France Telecom, Philips, Samsung
January 2006                              doc.: IEEE 802.22-06/0005r1

             Experimental Setup for DTV Detection
              8VSB_SOURCE                 MULTIPATH SIMULATOR




                            RECEIVER


                                                     ATTENUATOR




Submission                     Slide 95       ETRI, France Telecom, Philips, Samsung
January 2006                                                        doc.: IEEE 802.22-06/0005r1
             Experimental Test Results for DTV
                      Detection (1)
                              Based on DTV Laboratory Test Plan (Group C.1)
                                       “Static Echoes at various delays”.


                                                    ENERGY SENSOR,    VSB SENSOR,
                                                    DETECTION RATE, % DETECTION RATE, %
                      DELAY, ATTEN, DOPPLER,
                       usec       dB       Hz
                                                    PATH 1 POWER, dBm       PATH 1 POWER, dBm
                                                    -107     -100   -90     -107     -100    -90
             PATH 1     0         0         0

                       -5.0       0        0.05      100     100    100      95       100    100
             PATH 2   +3.0        0        0.05      100     100    100      95       100    100
                      +15.0       0        0.05      100     100    100      100      100    100
                      +30.0       0        0.05      100     100    100      100      100    100




Submission                                        Slide 96                ETRI, France Telecom, Philips, Samsung
January 2006                                                   doc.: IEEE 802.22-06/0005r1
             Experimental Test Results for DTV
                      Detection (2)
                       Based on DTV Laboratory Test Plan (Group D.1)
                                “Static multipath with AWGN”.




                                            ENERGY SENSOR,    VSB SENSOR,
                       DELAY, PHASE, ATTEN, DETECTION RATE, % DETECTION RATE, %
                        usec    dB     dB
                                            PATH 1 POWER, dBm PATH 1 POWER, dBm
                                              -107       -100 -90 -107 -100      -100
              PATH 1      0      0      0
              PATH 2    0.066   326    5.6
              PATH 3    0.073   151    6.1     100       100 100   100    100     100
              PATH 4    0.091   299    6.9
              PATH 5    0.026   298    14.8
              PATH 6    0.088   235    12.2



Submission                                    Slide 97             ETRI, France Telecom, Philips, Samsung
January 2006                                                    doc.: IEEE 802.22-06/0005r1
             Experimental Test Results for DTV
                      Detection (3)

                              Based on Doc.: IEEE802.22-05/0055r7.
                                               Profile A.

                                             ENERGY SENSOR,    VSB SENSOR,
                      DELAY, DOPPLER, ATTEN, DETECTION RATE, % DETECTION RATE, %
                       usec     Hz      dB
                                             PATH 1 POWER, dBm PATH 1 POWER, dBm
                                                  -107 -100 -90 -107          -100    -90
             PATH 1      0       0       0
             PATH 2     3.0     0.1     7.0
             PATH 3     8.0     2.5     15.0      100       100 100   100      100     100
             PATH 4    11.0    0.13     22.0
             PATH 5    13.0    0.17     24.0
             PATH 6    21.0    0.37     19.0



Submission                                      Slide 98              ETRI, France Telecom, Philips, Samsung
January 2006                                                   doc.: IEEE 802.22-06/0005r1
             Experimental Test Results for DTV
                      Detection (4)

                         Based on Doc.: IEEE802.22-05/0055r7.
                                         Profile B.


                                        ENERGY SENSOR,              VSB SENSOR,
                 DELAY, DOPPLER, ATTEN, DETECTION RATE, %           DETECTION RATE, %
                  usec     Hz       dB
                                            PATH 1 POWER, dBm PATH 1 POWER, dBm
                                              -107 -100 -90         -107    -100     -90
        PATH 1      0       0       0
        PATH 2    -3.0     0.1     6.0
        PATH 3     2.0    0.13     7.0       100        100   100   100      100     100
        PATH 4     4.0     2.5     22.0
        PATH 5     7.0    0.17     16.0
        PATH 6    11.0    0.37     20.0


Submission                                   Slide 99                ETRI, France Telecom, Philips, Samsung
January 2006                                                      doc.: IEEE 802.22-06/0005r1


                             Part 74 detection

 • Part 74 devices occupy a small portion of the spectrum
 • Thus, use spectral estimation and statistics of the
   estimated signal
    – Spectral estimation using FFTs (windowing techniques can alsoFFT
                                                                   be
             employed to better localize the spectrum)
                                                           K 1
                                                       1
              • Perform FFT               P ( k , m)       Y ( k  i , m)
                                                                              2

                                                       K   i 0
                                                                                                  avg
              • Average each freq bin                        N 1
                                                  m k   P ( k , m)
              • Average across freq bin                      m 0                                  W.F.
                                                             N 1
                                                   k   P ( k , m)  m k
                                                             m 0                             V>k*avg
       – Compute mean and “variance”

Submission                                   Slide 100               ETRI, France Telecom, Philips, Samsung
January 2006                                            doc.: IEEE 802.22-06/0005r1
                     Part 74 detection (cont.)

 • Detection
   max( P(k , m))  k1 m k  k 2  k

 • Theoretical performance

   Pr ob _ miss            ( K , K ) M
   Pr ob _ det ection  1  ( K , K ) M
   Pr ob _ false _ alarm.  1  ( K , K ) N




Submission                                  Slide 101      ETRI, France Telecom, Philips, Samsung
January 2006                         doc.: IEEE 802.22-06/0005r1

     Narrow-band detection (Part 74): Theoretical
            and simulated performance




Submission               Slide 102      ETRI, France Telecom, Philips, Samsung
January 2006                          doc.: IEEE 802.22-06/0005r1

      Probability of miss detection and false alarm




Submission                Slide 103      ETRI, France Telecom, Philips, Samsung
January 2006                          doc.: IEEE 802.22-06/0005r1


 MRSS: Multi-Resolution Spectrum Sensing

 • MRSS detect spectral components of incoming signal
   by the Fourier Transform.

 • Fourier Transform is performed in analog domain.

 • MRSS may utilize wavelet transforms as the basis
   function of the Fourier Transform.

 • Bandwidth, resolution and center frequency can be
   controlled by wavelet function

Submission                Slide 104      ETRI, France Telecom, Philips, Samsung
January 2006                                                                                                 doc.: IEEE 802.22-06/0005r1


                                          MRSS Schematics
                                Higher Layers: IP, ATM, 1394, etc.


                           Convergence Sublayer / Bridge (e.g., 802.1d)




                  MAC                       MAC                           MAC     Spectrum Manager
                                                          ...
                     PHY                    PHY                           PHY

                 PHY/MAC 1                PHY/MAC 2                   PHY/MAC n




 x(t)
                                                              X
                                                                                  z(t)                             y(t)
                                                                                                                              ADC

        Driver Amp                                    w(t)                                                 CLK#2


                                                                                         CLK#1
                                                                                                     Timing
                                              v(t)*fLO(t)                                                                                    MAC
                                                                                                      Clock

                                           Wavelet
                                          Generator
Submission                                                                              Slide 105                  ETRI, France Telecom, Philips, Samsung
January 2006                                    doc.: IEEE 802.22-06/0005r1


                     Advantage of MRSS

 • Full analog signal process
       – Drastically reduce power consumption
       – Faster recognition
 •    Flexibility in sensing resolution and speed
 •    Filter is not required on the sensing path
 •    Wideband operation
 •    Relaxing RF components constraint (Noise,
      Linearity…)




Submission                        Slide 106        ETRI, France Telecom, Philips, Samsung
January 2006                           doc.: IEEE 802.22-06/0005r1


               Non-linear effect of MRSS

 • Effect of the RF Mixer for MRSS is simulated and
   compared with Ideal multiplier

 • Three input tone (240MHz, 470MHz, 600MHZ) is
   assumed

 • Hann window with 5MHz bandwidth is selected as the
   wavelet

 • RF circuit model of double balanced mixer is used as
   multiplier
Submission                 Slide 107      ETRI, France Telecom, Philips, Samsung
January 2006                     doc.: IEEE 802.22-06/0005r1


               Ideal Multiplier




Submission           Slide 108      ETRI, France Telecom, Philips, Samsung
January 2006                    doc.: IEEE 802.22-06/0005r1


               LOmax = 10 dBm




Submission          Slide 109      ETRI, France Telecom, Philips, Samsung
January 2006                     doc.: IEEE 802.22-06/0005r1


               LOmax = -30 dBm




Submission           Slide 110      ETRI, France Telecom, Philips, Samsung
January 2006                            doc.: IEEE 802.22-06/0005r1


                   Result of MRSS

 • Mixer non-linear effect is significantly depend on the
   LO power level

 • RF mixer can be used as the multiplier, if operating in
   the linear mode

 • By adjusting LO power for wavelet generator can
   suppressing the unwanted harmonic component




Submission                  Slide 111      ETRI, France Telecom, Philips, Samsung
                        January 2006                                                                                                                doc.: IEEE 802.22-06/0005r1

                                                                    MRSS Simulation Results
                                                                     Wireless Microphone (FM) Signal


                                 40                                                                                               -50


                                 20                                                                                               -60
Power Spectrum Magnitude (dB)




                                  0                                                                                               -70


                                 -20                                                                                              -80




                                                                                                                      PSD (dB)
                                 -40                                                                                              -90


                                 -60                                                                                             -100


                                 -80                                                                                             -110


                                -100                                                                                             -120
                                       0    0.2   0.4   0.6   0.8        1    1.2   1.4   1.6   1.8          2                          0   0.2   0.4   0.6     0.8     1     1.2   1.4   1.6   1.8          2
                                                                    Frequency                                6                                                   Frequency (Hz)                              6
                                                                                                      x 10                                                                                            x 10




                                           The spectrum of the wireless                                                The corresponding signal spectrum
                                                microphone signal                                                      detected with the MRSS technique


                    Submission                                                                                   Slide 112                                    ETRI, France Telecom, Philips, Samsung
              January 2006                                                                                 doc.: IEEE 802.22-06/0005r1

)
B
d
                                                                    OFDM
(
e
d
u   40                                                                                     20
t
i
n
g   30
                                                                                           10
a
M
    20
m
u                                                                                     )     0
r                                                                                     B
t   10                                                                                d
c                                                                                     (
e                                                                                          -10
p                                                                                     D
S    0                                                                                S
                                                                                      P
r                                                                                          -20
e
w -10
o
P
                                                                                           -30
  -20


    -30                                                                                    -40
          0      0. 5   1   1.5   2       2.5   3   3.5   4   4.5          5                     0   0.5     1     1.5   2     2.5     3   3.5   4   4.5          5
                                      Frequency                        7                                                 Frequenc y (Hz)                      7
                                                                    x 10                                                                                   x 10

                                      Original                                                                            MRSS




              Submission                                                       Slide 113                         ETRI, France Telecom, Philips, Samsung
    January 2006                                                               doc.: IEEE 802.22-06/0005r1

      Feedback of sensing result and fusion rules
•    Option 1: Data fusion
     –    Each sensing element makes raw observations but does not make a decision as to whether a
          signal is present or not
     –    It processes the raw observations and sends the processed information to the CSDU. For eg.,
          each CPE may feed back quantized values of energy when in energy detector mode
     –    At the CSDU, the sensing reports from the Q reporting CPEs is fused using the decision:
                                                         Q
                 Declare signal present ( H 1) if  Ei  Tg ; else declare H 0
                                                         i 1
          •      Thresholds chosen so as to meet a pre-specified probability of false-alarm


•    Option 2: Decision fusion
     –    Each sensing element makes raw observations, processes these observations and makes a
          detection decision as to whether a signal is present or not
     –    It then sends the decision bit Di (1/0) to the CSDU
     –    At the CSDU, the individual decisions Di are fused into a final decision based on the following
                                                         Q

                                                                 D  T ; else declare H
          rule:
                   Declare signal present ( H 1) if                    i   g                      0
                                                                i 1
          •      Parameters chosen so as to meet a pre-specified probability of false-alarm
    Submission                                          Slide 114                 ETRI, France Telecom, Philips, Samsung
January 2006                                    doc.: IEEE 802.22-06/0005r1


                    Presentation Outline

 • Introduction
       – A Glimpse of IEEE 802.22


 • The PHY Proposal

 • The MAC Proposal

 • Conclusions




Submission                          Slide 115      ETRI, France Telecom, Philips, Samsung
January 2006                                             doc.: IEEE 802.22-06/0005r1


                     MAC Presentation Outline
 • Introduction

 • The MAC Protocol
       – Protocol architecture
       – MAC layer data communication
             • Superframe and Frame Structures
             • Network entry and initialization
             • Downstream and Upstream scheduling
       – Coexistence
             •   Incumbents
             •   Self-Coexistence
             •   Synchronization of overlapping BSs
             •   Clustering
       – Security

 • Performance Evaluation
Submission                                   Slide 116      ETRI, France Telecom, Philips, Samsung
January 2006                                                doc.: IEEE 802.22-06/0005r1


                                   Introduction
 • A MAC layer is proposed to be used for future IEEE 802.22
   WRANs

 • Some aspects of MAC have been inspired by the IEEE 802.16
   MAC standard

 • However, major enhancements have been made
       – Support of multiple channel operation;
       – Coexistence with both incumbents and itself (self-coexistence);
             •   Incumbent user avoidance and Measurements (incumbents and itself)
             •   Channel classification and Management
             •   Dynamic resource sharing, Coexistence Beacon Protocol (CBP), and Etiquette
             •   Synchronization of overlapping BSs
             •   Embedded wireless microphone beacon mechanism
       – Clustering support; etc.

Submission                                   Slide 117           ETRI, France Telecom, Philips, Samsung
January 2006                                             doc.: IEEE 802.22-06/0005r1


                     MAC Presentation Outline
 • Introduction

 • The MAC Protocol
       – Protocol architecture
       – MAC layer data communication
             • Superframe and Frame Structures
             • Network entry and initialization
             • Downstream and Upstream scheduling
       – Coexistence
             •   Incumbents
             •   Self-Coexistence
             •   Synchronization of overlapping BSs
             •   Clustering
       – Security

 • Performance Evaluation
Submission                                   Slide 118      ETRI, France Telecom, Philips, Samsung
January 2006                                     doc.: IEEE 802.22-06/0005r1


                            Overview
 • Given the very long
   propagation delays
   in WRANs, the BS
   regulates the
   medium access (for
   TDD/FDD)
       – Downstream: TDM
         (Time Division
         Multiplexing)
       – Upstream: DAMA
         (Demand Assigned
         Multiple Access)
         TDMA


                              Packet Size: 50 bytes                    Packet Size: 1500 bytes
Submission                    Slide 119               ETRI, France Telecom, Philips, Samsung
January 2006                                    doc.: IEEE 802.22-06/0005r1


                        Overview (cont.)

 • Combination of polling, contention and unsolicited
   bandwidth grants mechanisms

 • Support of Unicast/Multicast/Broadcast for both
   management and data

 • Connection-oriented MAC
       – Connection identifier (CID) is a key component
       – Defines a mapping between peer processes
       – Defines a service flow (QoS provisioning)


Submission                         Slide 120       ETRI, France Telecom, Philips, Samsung
January 2006                                                            doc.: IEEE 802.22-06/0005r1


               Protocol Stack Architecture

 • Flexibility, scalability and efficiency are core elements
       – Easy support of channel aggregation
       – Channel grouping and matching
 • Spectrum manager could be implemented in many ways
                             Higher Layers: IP, ATM, 1394, etc.


                        Convergence Sublayer / Bridge (e.g., 802.1d)




                 MAC                     MAC                           MAC             Spectrum Manager
                                                        ...
                  PHY                    PHY                           PHY

                PHY/MAC 1              PHY/MAC 2                   PHY/MAC n
Submission                                         Slide 121                   ETRI, France Telecom, Philips, Samsung
January 2006                                                                                  doc.: IEEE 802.22-06/0005r1


             Protocol Stack Architecture (cont.)

 • Flexible and scalable channel assignment
       – Implementers decide on the algorithm
             Used by another 802.22 cell




                                                                Used by another 802.22 cell
                                               Allocated




                                                                                                   Allocated


                                                                                                   Allocated
                                                to PHY/




                                                                                                    to PHY/


                                                                                                    to PHY/
                                                 MAC 1




                                                                                                     MAC 2


                                                                                                     MAC 3
             1                             2     3         4    5                                    6      7
                                                                                                                     Frequency

                      Used by incumbents (e.g., TV stations)

                     Vacant and available for use by 802.22



Submission                                                     Slide 122                         ETRI, France Telecom, Philips, Samsung
January 2006                                                                               doc.: IEEE 802.22-06/0005r1

                     Channel Grouping and Matching
• Multi-CH Resource Allocation
                                        DS                                                            US

                    1               2      3                       N           1’          2’        3’                 N’
                                                                 Multi-CH Resource Allocation (FDD case):             6MHz
                                                                 In order to scan all channel properly,
                    MAP                   MAP                    SM (Spectrum Manager) allocates to CPE
                                                                 some redundant channel information
                                                  Burst#5
                               DS




                                                            DS
                    Burst #1
         Burst #3




                                        Burst#4                  in both FA-1 MAP and FA-3 MAP.
                    Burst#2
 time                                     Burst #6
                                                                          BS                       MAP overhead for
                                                                                                   Specifying multi
                                                                                                   channel allocation

                                                                 1’ 3’
                                                                 1 3                         3’ 1’
                                                                                    3’       3 1
                                                                                    3 1’                             CPE 3
                                                     CPE 1                            1
                                                                                                    CPE 2

Submission                                                         Slide 123                    ETRI, France Telecom, Philips, Samsung
January 2006                                                                                    doc.: IEEE 802.22-06/0005r1

              Channel Grouping and Matching (cont.)

                                                                              Multi-CH Resource Allocation by CH Grouping:
                 CH-1 MAP                     CH-3 MAP                        The size of both FA-1 MAP and FA-3 MAP can be reduced
                                                                              by using the Channel Grouping and Matching




                                                         Burst#5
                             Burst #1
                  Burst #3




                                        DS




                                                                   DS
                                               Burst#4
                                                                              which is managed by SM (Spectrum Manager)
                             Burst#2
                                                 Burst #6
 time
                After Matching
                and Grouping
                                                                               BS                CH
                                                                                               Matching          CH Grouping:
                                               CH                                                              To select a group of
                                             Matching                   1’                                    CPE’s that are assigned
                                                                                                    3’         to the same channel
  CH-1MAP                                                               1
                                                                                          3’        3
              Burst #1
   Burst #3




                                               CPE 1                                      3
              Burst#2
                                                          CH Matching:
Before Matching
                                                         To select (US and                                               CPE 3
and Grouping                                             DS) active set 1 for
                                                          individual CPE                            CPE 2




Submission                                                                   Slide 124              ETRI, France Telecom, Philips, Samsung
January 2006                                             doc.: IEEE 802.22-06/0005r1


                     MAC Presentation Outline
 • Introduction

 • The MAC Protocol
       – Protocol architecture
       – MAC layer data communication
             • Superframe and Frame Structures
             • Network entry and initialization
             • Downstream and Upstream scheduling
       – Coexistence
             •   Incumbents
             •   Self-Coexistence
             •   Synchronization of overlapping BSs
             •   Clustering
       – Security

 • Performance Evaluation
Submission                                   Slide 125      ETRI, France Telecom, Philips, Samsung
January 2006                                         doc.: IEEE 802.22-06/0005r1


                Basic Terms and Definitions
 • Superframe
       – Defined and delimited by a preamble and the SCH (superframe control
         header). It is comprised of a number of Frames
 • Frame
       – Comprised of one DS and one US Subframe, where BS and CPEs use to
         communicate with each other
 • Subframe
       – Formed by a number of Bursts
 • Burst
       – Defined by a two dimensional segment of logical channel (frequency) and
         MAC slot (time). It may comprise of multiple MAC PDUs belonging to
         multiple CPEs
 • MAC PDU
       – The smallest unit of transmission/reception by the MAC. It is comprised
         of the MAC header, the payload, and CRC

Submission                             Slide 126         ETRI, France Telecom, Philips, Samsung
January 2006                                      doc.: IEEE 802.22-06/0005r1


                        Channel Bonding

 • Channel bonding offers enhanced capacity/data
   rate/range

 • To support channel bonding, we introduce a
   superframe structure that
       – Allows opportunistic and simultaneous use of multiple contiguous
         TV channels
       – Is dynamic and changes channel usage as channels become
         (un)available
       – Incorporates features that enable a multitude of mechanisms such
         as quiet period synchronization, better self-coexistence, and so on


Submission                           Slide 128        ETRI, France Telecom, Philips, Samsung
January 2006                                                                                         doc.: IEEE 802.22-06/0005r1


                                           Superframe Structure
                                                                                                                                            Time
     ...                  Superframe n-1                       Superframe n                              Superframe n+1               ...




           Preamble    SCH                 frame 0                             frame 1                  ...               frame m


                                                Superframe Control Header (SCH)

                                         • TV channels being bonded
                                         • Quiet period schedule
                                                                    Occupied by Incumbent
                                         • Coexistence and superframe information
                                               • Number and size of frames                Occupied by Incumbent
                                               • Information on periodic quiet periods
                 TV Channel
                     t-1
                            Preamble   SCH     • ID an transmit power of transmitter
     Frequency




                 TV Channel
                                         •Location configuration information
                                            Frame   Frame
                                                              Frame
                                                                      Frame
                            Preamble SCH                       ...    m-2                               Preamble SCH
                     t                         0        1                          m-1
                                                                     (Quiet)                 Frame
                                                                                                                       ... Frame    Frame          Frame
                                                                                               m                            0         1              n
                 TV Channel
                            Preamble SCH                                                                Preamble SCH
                     t+1




                                                                                Occupied by Incumbent




                                                                                                                                                   Time
Submission                                                              Slide 129                             ETRI, France Telecom, Philips, Samsung
January 2006                                doc.: IEEE 802.22-06/0005r1


                      Frame Structure

 • MAC is based on TDD/FDD frame structure

 • The MAC frame structure is comprised of two parts
       – A downstream (DS) subframe
       – An upstream (US) subframe




Submission                      Slide 130      ETRI, France Telecom, Philips, Samsung
January 2006                                                                                                                        doc.: IEEE 802.22-06/0005r1
                                         Time/Frequency Structure of a MAC
                                                      Frame
                                                                                                                                                                                            Time
                                  ...                       frame n-1                                frame n                                     frame n+1                      ...



                                                                                               MAC Slot Number

                                         k         k+1       k+3        k+5       k+7   k+9   k+11      k+13        k+15         k+17   k+20       k+23    k+26   k+29
                              s                    FCH                                                                                     Ranging
                                                                        Burst CPE #1
                        s+1
                                                                                                                                        UCS Notification
                        s+2
                                                                                                     Burst CPE #3                        BW Request
                                                                        Burst CPE #2




                                                                                                                                                                  coexistence
                                                                                                                                         Burst CPE #1




                                                                                                                                                                     Self-
                                                                                                                                                                                       TV Channel N
                                                                                                                                         Burst CPE #2
 Logical MAC Channel Number




                                                                                                                                         Burst CPE #3
                                                   DS-MAP




                                                                   Burst CPE #4                Burst CPE #5


                                                                                                                                         Burst CPE #4
                                        Preamble




                                                                                                                                         Burst CPE #5
                                                                                               Burst CPE #7




                                                                                                                                                                  coexistence
                                                                                                                                                                     Self-
                                                                   Burst CPE #6                                                          Burst CPE #6                                 TV Channel N+1

                                                                                               Burst CPE #8
                                                   US-MAP




                                                                                                                                         Burst CPE #7

                                                                                               Burst CPE #9
                                                                                                                                         Burst CPE #8
                        s+L

                                                                                                                           TTG
                                                                                  DS                                                                 US

Submission                                                                                            Slide 131                           ETRI, France Telecom, Philips, Samsung
January 2006                                                     doc.: IEEE 802.22-06/0005r1


             Network Entry and Initialization

 • BS and CPE initialization are key problems

                                                                   Radio range of
                                                                     TV station
                          Radio range of
                           802.22 BS

                                                                                                      TV
                                                                                                  station on
                                                                                                   channel
                                                         CPE 4
                                                                                                     #52
                 CPE 1

                                              BS on
                                           channel #52




                  CPE 2


                                   CPE 3


                                                                                Grade B contour
                                                                                 of TV station



Submission                                        Slide 132          ETRI, France Telecom, Philips, Samsung
January 2006                           doc.: IEEE 802.22-06/0005r1


        Network Entry and Initialization (BS)

 • BS consults TV usage database and regional WRAN
   information base to find potentially empty channels

 • BS performs sensing over these channels to check if
   they are indeed empty




Submission                 Slide 133      ETRI, France Telecom, Philips, Samsung
January 2006                                   doc.: IEEE 802.22-06/0005r1


      Network Entry and Initialization (CPE)
 1.    Scan channels searching for a BS.
 2.    Once SCH is received, ascertain that the use of the channel(s) is
       permitted (i.e., does not interfere with incumbents).
 3.    Synchronize to the BS.
 4.    Obtain the transmit parameters from the BS, which are
       contained in the UCD message.
 5.    Perform ranging and Negotiate basic capabilities.
 6.    Authorize CPE and Perform key exchange.
 7.    Perform registration.
 8.    If indicated as desired by the CPE during registration (REG-
       REQ message), perform other optional initialization procedures
       such as establish IP connectivity, establish time of day, and
       transfer operational parameters.
 9.    Set up connections.

Submission                         Slide 134      ETRI, France Telecom, Philips, Samsung
January 2006                                             doc.: IEEE 802.22-06/0005r1


                     MAC Presentation Outline
 • Introduction

 • The MAC Protocol
       – Protocol architecture
       – MAC layer data communication
             • Superframe and Frame Structures
             • Network entry and initialization
             • Downstream and Upstream scheduling
       – Coexistence
             •   Incumbents
             •   Self-Coexistence
             •   Synchronization of overlapping BSs
             •   Clustering
       – Security

 • Performance Evaluation
Submission                                   Slide 140      ETRI, France Telecom, Philips, Samsung
January 2006                                                 doc.: IEEE 802.22-06/0005r1


                                   Coexistence
 • Two primary types
       – With incumbents (TV service and Part 74 devices)
       – With other overlapping 802.22 cells
             • Self-Coexistence


 • Measurements can be classified as:
       – In-band
             • In case of incumbents, requires quiet periods (QP)
       – Out-of-band
             • No need for quiet periods


 • Coexistence is achieved by a joint application of:
       – Spectrum management (frequency and power)
       – “Interference-free” traffic scheduling (time)

Submission                                   Slide 141              ETRI, France Telecom, Philips, Samsung
January 2006                                    doc.: IEEE 802.22-06/0005r1


                          Measurements

 • Measurements form a key component of the MAC
       – Protection of incumbents and self-coexistence


 • The BS may request multiple measurements in a single
   management message
       – E.g., ATSC, DVB, Wireless Microphone, 802.22


 • Measurement messages may be transmitted through
   multicast
       – Allows the implementation of advanced features such as clustering
       – Bandwidth efficient

Submission                          Slide 142       ETRI, France Telecom, Philips, Samsung
January 2006                                           doc.: IEEE 802.22-06/0005r1


              Measurements: Messages (cont.)
 • Bulk Measurement Request (BLM-REQ)
       – Transmitted by the BS to CPEs
       – Includes information such as
             • Channels to measure
             • Multiple single measurement requests
 • Bulk Measurement Response (BLM-RSP)
       – Transmitted by CPE to BS
       – If needed, acknowledges the receipt of the BLM-REQ message
 • Bulk Measurement Report (BLM-REP)
       – Transmitted by CPE to BS
       – Returns multiple single measurement reports
 • Bulk Measurement Acknowledgement (BLM-ACK)
       – Transmitted by BS to CPE
       – Acknowledges receipt of measurement report

Submission                                 Slide 143      ETRI, France Telecom, Philips, Samsung
January 2006                                                            doc.: IEEE 802.22-06/0005r1


              Measurements: Requests (cont.)
 • Single measurements requests can be of various types
       – Signal specific measurement request
             • TV system and Wireless microphones
       – Beacon measurement request
             • CBP, BS, and Wireless microphone beacons
       – CPE statistics measurement request
       – Stop measurement request
       – Location configuration measurement request
 • A range of parameters can be specified
                                                     n measurement
                                                       repetitions




                            1                            2            . . .         n

                                                                                        Time

                         Duration   Restart Delay     Randomization
                                                         Interval
Submission                                          Slide 144                 ETRI, France Telecom, Philips, Samsung
January 2006                                            doc.: IEEE 802.22-06/0005r1


               Measurements: Reports (cont.)

 • Can be either regular or urgent

 • Some of the individual reports are:
       – Signal specific measurement report
             • TV/Wireless Microphone system type, measured value, precision, etc.
       – Beacon measurement report
             • Information on any CBP, BS, or Wireless microphone beacons
               received
       – CPE statistics measurement report
             • E.g., Packet error rate
       – Location configuration measurement report
             • If known, location information (GPS, triangulization, and so on)

Submission                               Slide 145          ETRI, France Telecom, Philips, Samsung
January 2006                                        doc.: IEEE 802.22-06/0005r1


                     Channel Management
 • Channel management is key to effective network coordination,
   coexistence and sharing

 • Included in two modes
       – Embedded
       – Non-embedded


 • A set of messages are defined to allow flexible management of
   channels, including:
       – Add/remove channel(s) to/from current set of channels
       – Switch channel(s) of operation
       – Quiet selected channel(s) – possibly to perform in-band measurement


Submission                             Slide 146        ETRI, France Telecom, Philips, Samsung
January 2006                                                   doc.: IEEE 802.22-06/0005r1


                   Channel Management (cont.)
 • Channel Set: Definitions
       -     Active set 1: a set of used channels for a certain CPE
       -     Active set 2: a set of used channels for a certain BS
       -     Candidate set: a set of clean channels available for a certain CPE and BS
       -     Occupied set: a set of occupied channels by incumbent user which a certain CPE finds
       -     Disallowed Set: a set of channels whose access are not allowed by regulation
       -     Null set : a set of channels that are not classified as one of above five sets

             * Note: The allowed set is defined by union of candidate set and null set depending on
                   channel’s SIR level

• Channel Set: Maintenance
      - Each BS maintains five channel sets: Active 1, Active 2, Occupied, Candidate, Null
      - Each CPE maintains four channel sets: Active 1, Active 2, Candidate, Occupied
      - If needed, each set is updated every quiet period (periodic or aperiodic)



Submission                                     Slide 147           ETRI, France Telecom, Philips, Samsung
January 2006                                                          doc.: IEEE 802.22-06/0005r1


                  Channel Management (cont.)
     Transition diagram for channel set
 ①    The channel in null, active or candidate set
      becomes a member of occupied set as incumbent
      user appears.
 ②    Incumbent service releases the channel and its                                    Null Set
      quality is better than an existing member of the
      candidate set, then it is classified as a member of
      candidate set.
 ③    Incumbent service releases the channel and its
      quality is worse than all member of the candidate
                                                                                           8
      set, then it is classified as a member of null set.
 ④    If the channel quality is better than an existing
      member of the candidate set, then it replaces the
                                                                  6       4                              3        1
      member of candidate set.
 ⑤    The channel becomes active by new allocation to a
      WRAN service.                                                                    Active Set
 ⑥    The poorest channel in candidate set goes to a
      member of null set as its quality is worse than a
      new member of candidate set, which comes from
      null(4), active(7) or occupied(2) sets                                   5   7                 1
 ⑦    The channel is released due to the termination of its
      usage and its quality is better than an existing
      member of the candidate set.
 ⑧    The channel is classified as a member of null set as                                1
      the WRAN service releases the channel and its            Candidate Set                             Occupied Set
      quality is worse than all member of the candidate                                   2
      set.

Submission                                         Slide 148             ETRI, France Telecom, Philips, Samsung
January 2006                                              doc.: IEEE 802.22-06/0005r1


                 Coexistence with Incumbents

 • Accomplished through the following steps:
       – Measurements (discussed earlier)

       – Detection
             • TV: For more info, please see PHY proposal.
             • Wireless Microphones
                – PHY solution: For more info, please see PHY proposal.
                – MAC solution: See next slide.


       – Incumbent Notification

       – Incumbent Detection Recovery

Submission                                 Slide 149          ETRI, France Telecom, Philips, Samsung
January 2006                                              doc.: IEEE 802.22-06/0005r1


                 Coexistence with Incumbents

 • Accomplished through the following steps:
       – Measurements (discussed earlier)

       – Detection
             • TV: For more info, please see PHY proposal.
             • Wireless Microphones
                – PHY solution: For more info, please see PHY proposal.
                – MAC solution: See next few slides.


       – Incumbent Notification

       – Incumbent Detection Recovery

Submission                                 Slide 150          ETRI, France Telecom, Philips, Samsung
January 2006                                               doc.: IEEE 802.22-06/0005r1
             MAC Layer Detection of Wireless
                    Microphones
 • From the transmitter perspective, wireless microphone beacons
   (WMB) can be of two types
       – Embedded
             • 802.22 device which has the additional capability of emitting WMBs (hereby
               referred to Class B CPE)
       – Non-embedded
             • Currently addressed by the Part 74 Task Group


 • Based on the proposed MAC layer, we have developed a reliable
   embedded WMB approach comprised of three steps:
       – Class B CPE Scanning and detection
       – Class B CPE Notification
       – BS Acknowledgement and Dissemination


Submission                                  Slide 151           ETRI, France Telecom, Philips, Samsung
January 2006                               doc.: IEEE 802.22-06/0005r1
         MAC Layer Detection of Wireless
        Microphones: Scanning and Detection
 • Class B CPE scans the desired channel in
   search for BS beacons
       – BS beacons contain quiet period schedules
 • A quiet period map is then constructed
             BS1


             BS2


             BS3


             BS4




                                                             Time


                                                   Quiet Period

                                                   802.22
                                                   Transmission



Submission                     Slide 152      ETRI, France Telecom, Philips, Samsung
January 2006                                    doc.: IEEE 802.22-06/0005r1
             MAC Layer Detection of Wireless
               Microphones: Notification
 • Class B CPE starts sending WMBs during the
   quiet periods of BSs

 • WMBs contain information such as:
       –     Service start time
       –     Service duration
       –     Location information
       –     Transmit power
       –     Security key

Submission                          Slide 153      ETRI, France Telecom, Philips, Samsung
January 2006                                            doc.: IEEE 802.22-06/0005r1
          MAC Layer Detection of Wireless
         Microphones: Acknowledgement and
                  Dissemination
 • Once the WMB is received by the BS or reported by
   any of its CPEs
       – Acknowledgement
             • The BS includes information in its own beacon about the presence of
               the wireless microphone
             • Network leaves the channel or reduces transmit power


       – Dissemination
             • Even after the network takes any appropriate action, the BS continues
               to advertise the wireless microphone operation in its beacon (for a
               time equivalent to Service Duration)


Submission                               Slide 154          ETRI, France Telecom, Philips, Samsung
January 2006                                 doc.: IEEE 802.22-06/0005r1


                  Incumbent Notification

 • The problem
       – How CPEs notify the BS about the presence of
         incumbents in a timely fashion?


 • Two modes are proposed:
       – Explicit Notification is executed first
       – Implicit Notification is then executed if Explicit
         Notification fails



Submission                       Slide 155      ETRI, France Telecom, Philips, Samsung
January 2006                                             doc.: IEEE 802.22-06/0005r1
                      Incumbent Notification:
                          Explicit Mode
 • Two solutions are possible
       – CPEs with upstream bandwidth allocation
             • Send report provided bandwidth and time are available; and
             • Set dedicated bits in MAC header
       – CPEs without upstream bandwidth allocation
             • Urgent Coexistence Situation (UCS) Notification slots reserved
               specifically for incumbent notification purposes
                – Can use either contention-based or contention-based CDMA access
             • The size of a slot fits the smallest MAC frame necessary to perform
               the incumbent notification: the MAC header
 • In both solutions, there is NO need to wait for a quiet
   period (QP) before recovery
       – CPEs can notify the BS at any point
Submission                                Slide 156          ETRI, France Telecom, Philips, Samsung
January 2006                                                                                                                           doc.: IEEE 802.22-06/0005r1
                                                                    Incumbent Notification:
                                                                     Explicit Mode (cont.)
                                                                                                                                                                                              Time
                                 ...                       frame n-1                                frame n                                       frame n+1                       ...



                                                                                               MAC Slot Number

                                        k         k+1       k+3        k+5       k+7   k+9   k+11      k+13        k+15         k+17     k+20       k+23    k+26   k+29
                             s                    FCH                                                                                       Ranging
                                                                       Burst CPE #1
                       s+1
                                                                                                                                         UCS Notification
                       s+2
                                                                                                    Burst CPE #3                          BW Request
                                                                       Burst CPE #2




                                                                                                                                                                   coexistence
                                                                                                                                          Burst CPE #1




                                                                                                                                                                      Self-
                                                                                                                                                                                         TV Channel N
                                                                                                                                          Burst CPE #2
Logical MAC Channel Number




                                                                                                                                          Burst CPE #3
                                                  DS-MAP




                                                                  Burst CPE #4                Burst CPE #5


                                                                                                                                          Burst CPE #4
                                       Preamble




                                                                                                                                          Burst CPE #5
                                                                                              Burst CPE #7




                                                                                                                                                                   coexistence
                                                                                                                                                                      Self-
                                                                  Burst CPE #6                                                            Burst CPE #6                                  TV Channel N+1

                                                                                              Burst CPE #8
                                                  US-MAP




                                                                                                                                          Burst CPE #7

                                                                                              Burst CPE #9
                                                                                                                                          Burst CPE #8
                       s+L

                                                                                                                          TTG                                                    RTG
                                                                                 DS                                                                   US

Submission                                                                                             Slide 157                             ETRI, France Telecom, Philips, Samsung
January 2006                                                       doc.: IEEE 802.22-06/0005r1
                        Incumbent Notification:
                         Explicit Mode (cont.)
 • The BS can use various strategies depending upon how
   reliable it wants the notification to be
       – Trade-off between overhead and data efficiency
       – Scalability
                                                     n Quiet
                                                     Periods




                1                                      2           . . .                n

                                                                                          Time

             Duration
                                         Normal System Operation
                      Quiet Period          Notification Phase
                    Notification Phase


Submission                                        Slide 158           ETRI, France Telecom, Philips, Samsung
January 2006                                          doc.: IEEE 802.22-06/0005r1
                     Incumbent Notification:
                         Implicit Mode
 • When the BS (CPE) does not receive expected
   communication from CPE (BS) within a pre-defined
   timeout
 • Then, the BS (CPE) assumes that an incumbent user
   has appeared in the channel

             Everything looks fine,
             so let me keep it up….


                                                                         집




                                          I found IU just had appeared,
                                          so I now have to search for new band….
                                          By the way, do he know about that?
Submission                            Slide 159           ETRI, France Telecom, Philips, Samsung
 January 2006                                                                   doc.: IEEE 802.22-06/0005r1

                                 Incumbent Notification:
                                  Implicit Mode (cont.)
• Short Implicit                                                                • Normal Implicit
                   BS                  CPE
                                                                                       BS                 CPE
                                               U
               QP
                    Fx:MAP
                                          QP                                       QP
                                                                                        Fx:Null
                                                                                                               QP
                                                                                   D
    Time-out




                        Fx:MAP




                                                                                                                    Time-out
                                                                                            Fx:Null
                        Fx:MAP


                                                                                            Fx:Null
                                                                                                      Fz:MAP




                                                                                                                      Initialization
                                 Fz:MAP
                                                                                   .
                                                                                   .




                                                                                                                        Expedite
                                                   Initialization



               .
               .                                                                   .                           .
                                                                                                               .
                                                     Expedite




               .                          .
                                          .                                                                    .
                                 Fz:MAP
                                          .                                                           Fz:MAP

                                                                                   QP
               QP                                                                       Fz:MAP                 QP
                    Fz:MAP                QP
                                                                                            BLM-REP
                        BLM-REP
                                                                                                Fz:MAP
                              Fz:MAP


 Submission                                                         Slide 160      ETRI, France Telecom, Philips, Samsung
January 2006                                   doc.: IEEE 802.22-06/0005r1


             Incumbent Detection Recovery

 • The problem
       – How does the 802.22 cell recover from an incumbent appearance
         in a timely fashion?




Submission                         Slide 161      ETRI, France Telecom, Philips, Samsung
January 2006                                          doc.: IEEE 802.22-06/0005r1


        Incumbent Detection Recovery (cont.)
 • The Incumbent Detection Recovery Protocol (IDRP)
       – Introduces the concept of Candidate/Backup Channel(s)

       – The 802.22 network not only performs in-band measurements, but
         also out-of-band measurements
             • Out-of-band measurements will determine suitable Candidate/Backup
               Channel(s)

       – The 802.22 network falls back to a Candidate/Backup Channel in
         case communication is preempted by an incumbent

       – The algorithms at both the BS and CPEs are provided
             • These algorithms also account for the case when no Candidate/Backup
               Channel is available

Submission                              Slide 162         ETRI, France Telecom, Philips, Samsung
January 2006                            doc.: IEEE 802.22-06/0005r1


                 Self-Coexistence

 • The general problem




                   TDMA Schedule
Submission                  Slide 163      ETRI, France Telecom, Philips, Samsung
January 2006                                 doc.: IEEE 802.22-06/0005r1


                    Self-Coexistence (cont.)
 • Indeed a major issue
       – E.g., 802.16h


 • Becomes even more
   critical in 802.22 given
       – The large coverage
         range
       – Its unlicensed nature


 • Directional antennas at
   CPEs do not address
   the problem


Submission                       Slide 164      ETRI, France Telecom, Philips, Samsung
January 2006                                                      doc.: IEEE 802.22-06/0005r1


                       Self-Coexistence (cont.)
 • Some approaches to better self-coexistence
       – Over the backhaul (i.e., wired)
             • Pros
                – 802.22 can wash its hands (throw the “hot potato” to somebody else)
             • Cons
                – Will there be really a “common backhaul” between competing WISPs? Can 802.22
                  rely on that?
                – What if this “common backhaul” is down?
                – Can 802.22 rely on the “upper layers” to take care of self-coexistence?
                – Coordination is an active process (e.g., quiet periods), and not a “once-in-a-month
                  thing”
       – Over-the-air
             • Pros
                – Built-in and self-healing 802.22 system
             • Cons
                – More complex MAC layer (but just a little more)

Submission                                      Slide 165              ETRI, France Telecom, Philips, Samsung
January 2006                                               doc.: IEEE 802.22-06/0005r1


                       Self-Coexistence (cont.)
 • Two solutions are proposed
       – BS beacon based
       – The Coexistence Beacon Protocol (CBP), which enables:
             • Sharing in time and frequency
             • Dynamic resource offering and renting
             • Etiquette for channel assignment


 • Both solutions:
       – Can be implemented either over-the-air or via a backbone
             • Here, we focus on the over-the-air implementation
       – Allow either one-way or two-way (i.e., negotiation) communication


 • The BS and its CPEs shall participate in the self-coexistence task

Submission                                  Slide 166              ETRI, France Telecom, Philips, Samsung
January 2006                                        doc.: IEEE 802.22-06/0005r1


                         Self-Coexistence (cont.)
 •    BS beacon based                   Case 1:
       – Implemented through
         overheard BS beacons

       – BS beacons carry various
         information:
             •   Channels used
             •   Quiet periods
             •   Frame information
             •   Transmit power level
                                        Case 2:


       – If needed, can use sensing
         antenna for this purpose

       – Allows better TPC and
         sharing in frequency only

Submission                              Slide 167      ETRI, France Telecom, Philips, Samsung
January 2006                                          doc.: IEEE 802.22-06/0005r1


                        Self-Coexistence (cont.)
 •    Coexistence Beacon
      Protocol (CBP)
       – CBP is executed by CPEs
         but under BS control

       – CPEs transmit coexistence
         packets with information
         about                                          CBP beacon   CBP beacon

             • The cell
             • This CPE’s reservations
               with the BS
             • Resource request
             • Channels from the active
               and candidate sets

       – Allows better TPC and
         sharing in both frequency
         and time


Submission                                Slide 168       ETRI, France Telecom, Philips, Samsung
January 2006                                                                                                                        doc.: IEEE 802.22-06/0005r1


                                                                    Self-Coexistence (cont.)
                                                                                                                                                                                            Time
                                  ...                       frame n-1                                frame n                                     frame n+1                      ...



                                                                                               MAC Slot Number

                                         k         k+1       k+3        k+5       k+7   k+9   k+11      k+13        k+15         k+17   k+20       k+23    k+26   k+29
                              s                    FCH                                                                                     Ranging
                                                                        Burst CPE #1
                        s+1
                                                                                                                                        UCS Notification
                        s+2
                                                                                                     Burst CPE #3                        BW Request
                                                                        Burst CPE #2




                                                                                                                                                                  coexistence
                                                                                                                                         Burst CPE #1




                                                                                                                                                                     Self-
                                                                                                                                                                                       TV Channel N
                                                                                                                                         Burst CPE #2
 Logical MAC Channel Number




                                                                                                                                         Burst CPE #3
                                                   DS-MAP




                                                                   Burst CPE #4                Burst CPE #5


                                                                                                                                         Burst CPE #4
                                        Preamble




                                                                                                                                         Burst CPE #5
                                                                                               Burst CPE #7




                                                                                                                                                                  coexistence
                                                                                                                                                                     Self-
                                                                   Burst CPE #6                                                          Burst CPE #6                                 TV Channel N+1

                                                                                               Burst CPE #8
                                                   US-MAP




                                                                                                                                         Burst CPE #7

                                                                                               Burst CPE #9
                                                                                                                                         Burst CPE #8
                        s+L

                                                                                                                           TTG
                                                                                  DS                                                                 US

Submission                                                                                            Slide 169                           ETRI, France Telecom, Philips, Samsung
January 2006                                            doc.: IEEE 802.22-06/0005r1
             But what does the CPEs do with this
                       information?
 • Report it to its associated BS

 • Future upstream bandwidth reservation requests can
   contain time allocation constraints
       – For example, a CPE can specify: “Give me 100Kb of airtime, but
         not between T1 and T2”


 • Note on the BS
       – Traffic Constraint (TRC-REQ/RSP) management messages are
         also available to the BS
              • For example, can be used before the BS allocates any time for the CPE
              • Allow the BS to inquire CPE about possible time allocation
                constraints

Submission                                Slide 170         ETRI, France Telecom, Philips, Samsung
January 2006                                     doc.: IEEE 802.22-06/0005r1


    Then, what does the BS do about all this?
 • If possible and desirable,
   avoid each other by
   switching channels
 • Better TPC
 • Implement
   “interference-free”
   scheduling
       – Sharing in time and
         frequency
 • In case of Resource
   Request
       – Following CBP packets
         contain channels from
         the active/candidate sets

Submission                           Slide 171      ETRI, France Telecom, Philips, Samsung
January 2006                                             doc.: IEEE 802.22-06/0005r1


                            Resource Renting

 • When
       – A BS (Offerer) already acquired TV channels, and if other BSs
         (Renter) cannot secure the required resource (in the case where
         vacant TV Channels are not available)


 • Then
       – Renter can request a resource partition to the Offerer
             • Resource partition ratio between different BSs is outside of this
               proposal (pre-determined)




Submission                                Slide 172          ETRI, France Telecom, Philips, Samsung
January 2006                                                            doc.: IEEE 802.22-06/0005r1


                             Resource Offering

 • Step-by-step procedure between Offeror and Renter
       –     1) Offeror broadcasts its unused TV channel(s)
       –     2) Renter requests its desired TV channel(s) and usage duration
       –     3) Offeror confirms the allocation
       –     4) Renter sends back an ACK
       –     5) Renter shall return the borrowed resource before the rental
             duration expires

                        Resource               Resource
                      Advertisement        Renting Response
         Offeror
                                  Resource                 Resource
                                                                                           CBP
                                Renting Request           Renting ACK

         Renter
                                                                                           CBP


Submission                                        Slide 173                ETRI, France Telecom, Philips, Samsung
January 2006                            doc.: IEEE 802.22-06/0005r1


             Etiquette for Channel Assignment

 • CBP together with the renter-offerer mechanism is
   used to gather channel usage information in
   neighboring BSs

 • The etiquette is the algorithm used to select the
   appropriate channel that minimizes interference
   among collocated/neighboring WRANs




Submission                  Slide 174      ETRI, France Telecom, Philips, Samsung
 January 2006                                                     doc.: IEEE 802.22-06/0005r1


                                                                  Etiquette Example

                                             N1:                      N2:
                                            1,2,3                    1,5,6
                                                        1,3,4,6,7

                                                           N3:
                                                          1,4,8



                     Neighbor 1   Neighbor 2            Neighbor 3                   Central

   Active Set          1,2,3        1,5,6                 1,4,8

U (Candidate sets)                                                                  1,3,4,6,7

  1st Selection                                                                         7

  2nd Selection                                                              4 (randomly from 3,4,6)

 Final Selection                                                              3 (randomly from 3,,6)

 Submission                                 Slide 175                ETRI, France Telecom, Philips, Samsung
January 2006                                                        doc.: IEEE 802.22-06/0005r1


             Synchronization of Overlapping BSs
 • The problem
       – Frames of co-channel overlapping BSs are asynchronous, which makes
         coexistence even harder

  BS1:              frame 0                 frame 1                ...             frame m


  BS2:                        frame 0                    frame 1             ...             frame m



                                                                                                         Time

 • Numerous benefits to synchronization
       – Incumbent protection
              • Quiet period synchronization of overlapping BSs
              • Improved detection
       – Self-Coexistence
              • Logical channel amongst overlapping BSs
              • Efficient sharing of resources
Submission                                   Slide 176                   ETRI, France Telecom, Philips, Samsung
January 2006                                              doc.: IEEE 802.22-06/0005r1


 Synchronization of Overlapping BSs (cont.)

 • Two steps in synchronization
       – Establishment
       – Confirmation and maintenance


 • Establishment
       – Done through self-coexistence quiet periods and CBP
                      Transmission Offset


   Frame n at BS1:                                                ...




   Frame m at BS2:               ...


                                       Reception Offset

                                                                                     Time
Submission                                   Slide 177       ETRI, France Telecom, Philips, Samsung
 January 2006                                                            doc.: IEEE 802.22-06/0005r1


  Synchronization of Overlapping BSs (cont.)

  • Establishment
           – The synchronization rule guarantees that the system will converge
                                                     Slide Count                         Partial frame


Preamble   SCH         frame 0            frame 1          ...     frame n-1            Preamble         SCH   frame 0

                                                                                          Slide Amount
                 CBP Packet



     frame m-3                frame m-2        frame m-1              frame m           Preamble         SCH   frame 0



                                                                                                                         Time


           – Frame slide messages are defined that allow synchronization to be
             accomplished
           – At the time of synchronization, overlapping quiet periods shall also
             be synchronized (this depends on the quiet period schedule)

Submission                                          Slide 178                   ETRI, France Telecom, Philips, Samsung
January 2006                                                                                                                                           doc.: IEEE 802.22-06/0005r1


 Synchronization of Overlapping BSs (cont.)
 • Synchronization is confirmed by receiving a CBP packet during
   the self-coexistence window
                                                                                                                        MAC Slot Number

                                                              k         k+1      k+3         k+5       k+7   k+9       k+11          k+13       k+15         k+17       k+20       k+23       k+26       k+29
                                                       s                FCH                                                                                             UCS Notification
                                                                                             Burst CPE #1
                                                 s+1
                                                                                                                                                                          BW Request
                          Logical MAC Channel Number




                                                 s+2
                                                                                                                                 Burst CPE #3
                                                                        DS-MAP




                                                                                             Burst CPE #2                                                                Burst CPE #1




                                                                                                                                                                                                         coexistence
                                                             Preamble




                                                                                                                                                                                                            Self-
        Frame n at BS1:
                                                                                                                                                                         Burst CPE #2

                                                                                                                                                                         Burst CPE #3
                                                                                        Burst CPE #4                        Burst CPE #5
                                                                        US-MAP




                                                                                                                                                                         Burst CPE #4
                                                       s+L

                                                                                                                                                       TTG

                                                                                                                                                                                           CBP packets

                                                       s                FCH                                                                                  UCS Notification
                                                                                       Burst CPE #1
                                                 s+1
                                                                                                                                                              BW Request
                          Logical MAC Channel Number




                                                 s+2
                                                                                                             Burst CPE #3
                                                                        DS-MAP




                                                                                       Burst CPE #2                                                           Burst CPE #1




                                                                                                                                                                                                         coexistence
                                                             Preamble




                                                                                                                                                                                                            Self-
        Frame m at BS2:
                                                                                                                                                              Burst CPE #2

                                                                                                                                                              Burst CPE #3
                                                                                       Burst CPE #4          Burst CPE #5
                                                                        US-MAP




                                                                                                                                                              Burst CPE #4
                                                       s+L

                                                                                                                                 TTG



                                                                                                                                                                                                     Time

Submission                                                                                                    Slide 179                                          ETRI, France Telecom, Philips, Samsung
January 2006                                               doc.: IEEE 802.22-06/0005r1


                               Clustering
 • Alleviate much of the redundancy
   involved in the execution of the                                                            Cluster


   coexistence mechanisms
       – So, very suitable for 802.22                CPE




       – Can be employed in all coexistence
         mechanisms, except for the protection
         of Wireless Microphone services
 • Based on key observations                                                   BS




       – Sensing outcome of close-by CPEs are
         likely to be “similar”
       – CPEs are stationary
 • It is a two-step process conducted by
   the BS
       – Formation of Physical Cluster
       – Formation of Logical Cluster

Submission                               Slide 180            ETRI, France Telecom, Philips, Samsung
January 2006                                         doc.: IEEE 802.22-06/0005r1


             Clustering: Physical Cluster (cont.)
 • Creation of Physical
   Clusters is totally localized                                                       Physical
                                                                                       Cluster




   at the BS                                   CPE



       – No direct involvement from
         CPEs

                                                                       BS


 • The BS groups together
   CPEs sensing “similar”
   characteristics of the
   incumbent signal
       – Could also be based on location
         relative to the incumbent
         transmitter

Submission                         Slide 181            ETRI, France Telecom, Philips, Samsung
January 2006                                                            doc.: IEEE 802.22-06/0005r1


                          Clustering: Physical Cluster (cont.)
 • Based on the well-known k-
   means clustering algorithm
 • The algorithm
                        – Initially, no clustering
                        – CPEs report measurements to
                          the BS (BLM-REP) which
                          constructs incumbent profiles
                        – Then, the BS runs the
                          clustering algorithm
   Received incumbent
     signal strength




                                         Nearby (or
                                        high power)
                                        incumbent




                                         Far away (or
                                          low power)
                                          incumbent




                                                        Frequency

Submission                                                  Slide 182      ETRI, France Telecom, Philips, Samsung
January 2006                                                      doc.: IEEE 802.22-06/0005r1


             Clustering: Logical Cluster (cont.)
                                                                                                                              Physical


 • Formed by CPEs                                                                                                             Cluster




   belonging to different                  CPE



   Physical Clusters

 • Allows the BS to group                                                                    BS



   those CPEs that are less
   likely to contend for the
   same airtime
                                     Logical
                                     Cluster

 • CPEs within a Logical
   Cluster perform the same
   “coexistence task”                            Exemplary assignment for                  Exemplary assignment
                                                 incumbent measurements:                   for CBP:
                                                       ATSC           NTSC     DVB   All          CBP at T1       CBP at T2   CBP at T3   All




Submission                     Slide 183                                     ETRI, France Telecom, Philips, Samsung
January 2006                                             doc.: IEEE 802.22-06/0005r1


                     MAC Presentation Outline
 • Introduction

 • The MAC Protocol
       – Protocol architecture
       – MAC layer data communication
             • Superframe and Frame Structures
             • Network entry and initialization
             • Downstream and Upstream scheduling
       – Coexistence
             •   Incumbents
             •   Self-Coexistence
             •   Synchronization of overlapping BSs
             •   Clustering
       – Security

 • Performance Evaluation
Submission                                   Slide 184      ETRI, France Telecom, Philips, Samsung
January 2006                                             doc.: IEEE 802.22-06/0005r1


                     MAC Presentation Outline
 • Introduction

 • The MAC Protocol
       – Protocol architecture
       – MAC layer data communication
             • Superframe and Frame Structures
             • Network entry and initialization
             • Downstream and Upstream scheduling
       – Coexistence
             •   Incumbents
             •   Self-Coexistence
             •   Synchronization of overlapping BSs
             •   Clustering
       – Security

 • Performance Evaluation
Submission                                   Slide 188      ETRI, France Telecom, Philips, Samsung
January 2006                                           doc.: IEEE 802.22-06/0005r1


                      Performance Evaluation
 • All aspects of the MAC are being implemented in OPNET
       – OPNET is considered the most well-reputated and reliable network
         simulation tool available today

 • In all simulations:
       – In case of quiet periods (QP), every CPE performs detection in all in-band
         channels (e.g., N-1, N, and N+1 in case of a single TV channel)
       – DFS model is implemented as per the requirements document
       – No fragmentation or packing

 • Some common simulation parameters
       –     Superframe size = 12 frames, where Frame size = 40 ms
       –     Packet size = 1 Kbyte
       –     Detection time per TV channel = 13 ms
       –     64-QAM rate 2/3 and Symbol time = 310 µs
Submission                               Slide 189         ETRI, France Telecom, Philips, Samsung
January 2006                                doc.: IEEE 802.22-06/0005r1


             Throughput at the MAC SAP
 • Evaluate the throughput of
   the MAC under varying
   number of bonded TV
   channels

 • 1 BS and 127 CPEs




Submission                      Slide 190      ETRI, France Telecom, Philips, Samsung
January 2006                             doc.: IEEE 802.22-06/0005r1


         Throughput at the MAC SAP (cont.)
 • Impact of QP on
   throughput is
   more confined to
   high load
   scenarios
       – The scheduler can
         properly handle
         this


 • Channel bonding
   provides
   significant
   performance
   improvement

Submission                   Slide 191      ETRI, France Telecom, Philips, Samsung
January 2006                                doc.: IEEE 802.22-06/0005r1


                         Channel Efficiency
 • Evaluate the
   channel
   utilization
       – The overall
         impact of QPs
         is only
         noticeable in
         high loads


 • Fragmentation
   and packing can
   improve these
   figures even
   more

Submission                      Slide 192      ETRI, France Telecom, Philips, Samsung
January 2006                                       doc.: IEEE 802.22-06/0005r1


                     Network Joining Time
 • Evaluate, for the worst case
   scenario, the average network
   joining time by a CPE
       – CPEs first scan channel for a
         time equivalent to a frame size
       – CPE stays in a channel for a
         superframe duration after that
       – This is followed by network
         entry and initialization


 • More efficient algorithms can
   be easily implemented



Submission                             Slide 193      ETRI, France Telecom, Philips, Samsung
January 2006                          doc.: IEEE 802.22-06/0005r1


              Network Joining Time (cont.)
 • 1 BS and 127
   CPEs
       – BS is powered
         up at
         simulation
         startup
       – CPEs power
         up at random
         times


 • 802.22 FRD
   requires joining
   time under 10
   sec

Submission                Slide 194      ETRI, France Telecom, Philips, Samsung
January 2006                                            doc.: IEEE 802.22-06/0005r1


                             Impact on QoS
 •    Evaluate the impact of quiet
      periods and incumbents on QoS

 •    Traffic pattern
       – A total of 3 Mbps constant
         aggregate US traffic
       – DS traffic varies between 3 Mbps
         and 15 Mbps


 •    All 127 CPEs establish
      connections with BS
       – Out of these, 4 real time (QoS)
         connections at 32 Kbps each
       – Other connections are BE or non-
         real time

Submission                                  Slide 195      ETRI, France Telecom, Philips, Samsung
January 2006                                  doc.: IEEE 802.22-06/0005r1


                      Impact on QoS (cont.)
 • The overall                                    Effect of Queuing
   impact on
   average
   downstream             (sec)
   delay is very
   small
       – QoS can be
         satisfied to a
         large extent




Submission                        Slide 196      ETRI, France Telecom, Philips, Samsung
January 2006                                  doc.: IEEE 802.22-06/0005r1


                     Impact on QoS (cont.)
 • The overall
   impact on
   average
   upstream delay
                          (sec)
   is not so small
   as in the
   downstream
   case
       – Despite of
         that, QoS can
         still be
         satisfied to a
         significant
         extent


Submission                        Slide 197      ETRI, France Telecom, Philips, Samsung
January 2006                                 doc.: IEEE 802.22-06/0005r1


                   Handling of Incumbents
 • Evaluate the detection,
   notification and recovery
   capability of the MAC

 • 1 BS and 9 CPEs

 • TV station starts in-band
   operation at a random time
       – Incumbent is detected
         during quiet period




Submission                       Slide 198      ETRI, France Telecom, Philips, Samsung
January 2006                               doc.: IEEE 802.22-06/0005r1


             Handling of Incumbents (cont.)
 • Network operation
   is quickly restored
       – BS and unaffected                Channel A                       Channel B
         CPEs switch to
         Candidate/Backup
         Channel

       – CPEs who do not
         receive switch
         message go to
         Candidate/Backup
         Channel after
         timeout (2 frames)



Submission                    Slide 199        ETRI, France Telecom, Philips, Samsung
January 2006                              doc.: IEEE 802.22-06/0005r1


             Handling of Incumbents (cont.)
 • Evaluate the
   dynamics of                          Channel A                      Channel B
   channel bonding
       – Together with
         handling of
         incumbents
       – Network can
         switch to one or
         more
         Candidate/Backup
         Channel




Submission                  Slide 200          ETRI, France Telecom, Philips, Samsung
January 2006                                                  doc.: IEEE 802.22-06/0005r1


                     CBP/Synchronization
 • Evaluate the self-coexistence
   mechanisms of the proposed
   MAC
       – Synchronization                            1 cell:
       – CBP in every frame

 • The number of overlapping
   802.22 cells are progressively
   increased
       – Up to 4 cells are simulated
       – BSs and CPEs start at random
                                                2 cells:
 • Network is fully loaded and
   traffic is uniform

Submission                              Slide 201                ETRI, France Telecom, Philips, Samsung
January 2006                                doc.: IEEE 802.22-06/0005r1


                    CBP/Synchronization (cont.)



             3 cells:




             4 cells:




Submission                      Slide 202      ETRI, France Telecom, Philips, Samsung
January 2006                                            doc.: IEEE 802.22-06/0005r1


                   CBP/Synchronization (cont.)




             Network Synchronization Time                     Local Drift Time
Submission                                  Slide 203      ETRI, France Telecom, Philips, Samsung
January 2006                                         doc.: IEEE 802.22-06/0005r1


               CBP/Synchronization (cont.)
 • Simple scheduler

 • CBP together with
   Synchronization can provide
   significant performance
   improvements
       – Since CBP is under control of
         the BS, it can be made
         adaptive




Submission                               Slide 204      ETRI, France Telecom, Philips, Samsung
January 2006                                    doc.: IEEE 802.22-06/0005r1


                    Presentation Outline

 • Introduction
       – A Glimpse of IEEE 802.22


 • The PHY Proposal

 • The MAC Proposal

 • Conclusions




Submission                          Slide 205      ETRI, France Telecom, Philips, Samsung
January 2006                                         doc.: IEEE 802.22-06/0005r1


                                  Conclusions
 • Proposed a PHY and MAC that addresses the requirements set
   forth by the 802.22 WG

 • PHY
       – Based on OFDMA
       – Flexible channel configurations
       – TV and Part 74 service detection and protection


 • MAC
       – Coexistence is a key feature
             • Incumbent protection
             • Self-coexistence
       – CBP, dynamic resource sharing, channel bonding, etc.

Submission                              Slide 206          ETRI, France Telecom, Philips, Samsung
January 2006                       doc.: IEEE 802.22-06/0005r1


                  Appendix A

 • WRAN maximum transmit power constraint
   for interference management and coexistence




Submission             Slide 207      ETRI, France Telecom, Philips, Samsung
January 2006                                                            doc.: IEEE 802.22-06/0005r1
              Place of proposed interference
             management module in the system




                                                                                                        QoS scheduling & resource allocation (RRM):
                                                                                                        • in opportunistic spectrum access channels
                                                                                                          • in dedicated channels (for coexistence)
                       Interference management module
                                                        Module that
                                                      computes the
                            Footprints of incumbent
                            and coexisting WRANs


      Database                                          constraints
                                                      relative to the
                                                      protection of
                                  Radio map


                                                       incumbents         Set of minimum
Sensing measurements                                                    constraints for QoS
                                                                            scheduler
                                                       Module that         optimization
                                                      computes the
                                                       constraints
                                                        relative to
                                                      coexistence




                                Constraints from WRANs negotiation outcome

Submission                                              Slide 208           ETRI, France Telecom, Philips, Samsung
January 2006                                                       doc.: IEEE 802.22-06/0005r1

  Individual maximum transmit power constraint, and joint
 maximum transmit power constraint rule in constraint areas

                                                                             WRAN BS
                             Limit of service provision whenever
                             channel N is occupied by TV                                  P = 4W if alone
                             operation by this TV station




                                                  P=0                            P < 4W

                                                                   P=0


                      d                P=0                                                P < 4W


               CPE                                                               Joint maximum power
                                                                                  constraint rule in this
                                                                                     constraint area
                     150 m
                                                         P=0
                                      NTSC TV transmitter
                                         in Channel N
                                         Grade B


                4.7 km
                             dmin




Submission                                    Slide 209                  ETRI, France Telecom, Philips, Samsung
January 2006                                           doc.: IEEE 802.22-06/0005r1

   Individual and joint transmit power constraints
 • Individual power constraint is required to meet the D/U minimum
   levels at the nearest TV receivers in co-channel and adjacent
   channel operations.
       – Guarantee that a single CPE transmitting over a 6 MHz band at the
         maximum transmit power constraint will just meet the interference
         requirements (in fact there is some margin due to fading).

 • Joint power constraint
       – In the case of simultaneous transmission of multiple CPEs in an
         aggregated bandwidth larger than 6 MHz, if each CPE uses the above
         individual power constraint, the D/U ratio will be too low at the nearest
         TV receiver.
       – Application: maybe rarely, mostly for coexistence of WRANs in some
         small overlapping area close to a Grade B/noise-protected contour with
         operation co-channel to a TV station.



Submission                              Slide 210          ETRI, France Telecom, Philips, Samsung
January 2006                                                        doc.: IEEE 802.22-06/0005r1
        Justification of 150 m margin for first
             adjacent channels operation
•    Calculations show that [2]
      A CPE transmitting at 4W with TV operation on channel N should be:
             •   At least 10 km away from noise-protected contour co-channel to DTV operation
             •   At least 123 m away from noise-protected contour on N-1 of DTV operation
             •   At least 155 m away from noise-protected contour on N+1 of DTV operation
             •   At least 4.7 km away from Grade B contour co-channel to NTSC operation
             •   At least 44 m away from Grade B contour on N-1 of NTSC operation
             •   At least 31 m away from Grade B contour on N+1 of NTSC operation

•    Thus a 150 m margin beyond the Grade B/noise-protected contours can be
     given to take care of all first adjacent channel constraints, and would only
     affect a marginal number of potential WRAN customers.
•    An additional margin can be given if needed based on accuracy of
     distributed sensing measurements, and to take care of outage due to fading.




Submission                                        Slide 211              ETRI, France Telecom, Philips, Samsung
January 2006                                                                                                                     doc.: IEEE 802.22-06/0005r1


    Individual CPE transmit power constraint
                                                                 start
                                                                                                                                For one given CPE, determine the
                       1
                                                             2
                                                                                                                               constraints on all bands incurred by
                                                                       TV
                  Max power = 4W
                                          No                       operation                 Yes                                possible TV operation on band N
                                                                    in band
                                                                       N?
                                                                                         3
                                                                                                                                     fill one column of Table 1
                                                                                  Yes          CPE in                          No
                                                                                               grade B
                                                                                              contour +
       5                                                                                       150 m?
                                                                                                                      4

• Add to list of disallowed bands: N-1, N, N+1
• Set max power constraint from EIRP(DTV) on                                                                      Distance > 4.7 km (NTSC)?
other bands                                                                                                                                                  Yes
                                                                                    No                             Distance > 10 km (DTV)?


                                                                                                                                                  8
                                                                              7                                                                       Max power = 4W
       6
               Update Table 1
                 Column N                                                                                                                     9
                                                                     No       Distance > d_min?             Yes
                                                                                (NTSC or DTV)
                                                      10                                                                    12
                                                                                                                                                      Update Table 1
                                                                                                                                                        Column N

                                                           No transmission on                            Limit max transmit power as
                                                                channel N                                   a function of distance
                                                                                                                                     -a
                                                                                                                              æ ö
                                                                                                                               d
                                                                                                        Pt ,k ,max (dk ) = Po ç o ÷
                                                                                                                              ç ÷
                                                 11                                                                           è ÷
                                                                                                                              çdk ø
                                                                                                                                  ÷
                                                             Update Table 1
                                                               Column N

                                                                                                   13
                                                                                                              Update Table 1
                                                                                                                Column N



Submission                                                                                    Slide 212                                   ETRI, France Telecom, Philips, Samsung
January 2006                                                                                                      doc.: IEEE 802.22-06/0005r1
 Maximum power constraint for a single CPE operation (out-of-band emission
      mask is assumed to meet the functional requirement 15.1.7 [1])
                            Table 1 (example)
           TV band            1                     2                3                   4                 5                 6                     7                8
                            No TV                  TV              No TV                TV               No TV             No TV                  TV              No TV

       CPE location     Outside grade B      Inside grade B    Outside grade B    Outside grade B    Inside grade B    Outside grade B      Inside grade B
 CPE operation on          Distance                               Distance           Distance                             Distance

     TV band 1         4W                 Not allowed         4W                 4W                 4W                4W                 EIRP(-6)            4W
                                          (adjacent band)




     TV band 2         4W                 Not allowed         4W                 4W                 4W                4W                 EIRP(-5)            4W




     TV band 3         4W                 Not allowed         4W                 4W                 4W                4W                 EIRP(-4)            4W
                                          (adjacent band)                        @ 150 m DTV
                                                                                 @ 44 m NTSC


     TV band 4         4W                 EIRP(+2)            4W                 4W                 4W                4W                 EIRP(-3)            4W
                                                                                 @ 10 km DTV
                                                                                 @ 4.7 km NTSC


     TV band 5         4W                 EIRP(+3)            4W                 4W                 4W                4W                 EIRP(-2)            4W
                                                                                 @ 150 m DTV
                                                                                 @ 31 m NTSC


     TV band 6         4W                 EIRP(+4)            4W                 4W                 4W                4W                 Not allowed         4W
                                                                                                                                         (adjacent band)




     TV band 7         4W                 EIRP(+5)            4W                 4W                 4W                4W                 Not allowed         4W




                      All values assume a 6 MHz bandwidth used by the CPE. They need to be scaled
                         down later to the bandwidth actually used by the CPE within a TV band.
Submission                                                                         Slide 213                          ETRI, France Telecom, Philips, Samsung
   January 2006                                     doc.: IEEE 802.22-06/0005r1
        Maximum power constraint for all CPEs (out-of-band emission mask is
                assumed to meet the functional requirement 15.1.7 [1])
                                  Table 2 (example)

                            CPE   CPE #1                                             CPE #2                                       CPE #3
                                  (Constraint Area #1)                               (Contraint Area #1)                          Area #2
CPE operation on

              TV band 1           Not allowed                                        Not allowed                                  x



              TV band 2           Not allowed                                        Not allowed                                  x



              TV band 3           Not allowed                                        Not allowed                                  x



              TV band 4           EIRP(-3)                                           EIRP(-3)                                     x
                                  (Outside grade B operation at distance d1)         (Outside grade B operation at distance d2)


              TV band 5           EIRP(+3)                                           EIRP(+3)                                     x



              TV band 6           Not allowed                                        Not allowed                                  x



              TV band 7           Not allowed                                        Not allowed                                  x




                   All values assume a 6 MHz bandwidth used by the CPE. They need to be scaled
                      down later to the bandwidth actually used by the CPE within a TV band.
  Submission                                                             Slide 214                  ETRI, France Telecom, Philips, Samsung
    January 2006                                          doc.: IEEE 802.22-06/0005r1

            Joint CPEs transmit power constraint
•     A single transmitting CPE induces power at TV receiver:

                               Pr = Pt ,kdk- a
      Where dk is the distance of the CPE to the Grade B contour, and a is the path
      loss exponent. Let n be the density of CPEs in a local area (a few km2).

•     Multiple transmitting CPEs: effective path loss exponent is decreased
       Maximum transmit power rule:

                      Pt ,k = Pt (n , dk , Pt ,k ,max (dk ))
        Power at the nearest TV receiver:

                       Pr =    åk
                                    dk- a Pt (n , dk , Pt ,k ,max (dk ))
      One rule can address interference to incumbent from the same and coexisting
       WRANs given limited on the CPEs of all WRANs within a constraint area.
    Submission                              Slide 215          ETRI, France Telecom, Philips, Samsung
                             January 2006                        doc.: IEEE 802.22-06/0005r1


                                     Joint CPEs transmit power constraint
incumbents exceeded
 Interference limit to




                                                                                     Pt ,k = Po

                                                                                                 Po
                                                                                     Pt ,k =
                                                                                                 K
                                                                                             Podo- a
incumbents below threshold




                                                                                     Pt ,k =
                                                                                             å
    Interference limit to




                                                                                                dk- a




                             Submission              Slide 216      ETRI, France Telecom, Philips, Samsung
 January 2006                        doc.: IEEE 802.22-06/0005r1


         Joint CPEs transmit power constraint


4W
                                                          Pt ,k = Po

                                                                       Po
                                                          Pt ,k =
                                                                       K
                                                                  Podo- a
                                                          Pt ,k =
                                                                  å  dk- a




 Submission              Slide 217      ETRI, France Telecom, Philips, Samsung
 January 2006                                    doc.: IEEE 802.22-06/0005r1


   Required cooperation between WRAN BSs
• WRANs determine overlapping area on co-channel operation close to
  a Grade B/noise-protected contour, and lists the CPEs in that area.

• Each WRAN estimates the weight wi =        ådk- a from the knowledge of
  the distance of its own CPEs to the protected contour.

• WRANs exchange these values.

• WRANs scale the maximum transmit power of their CPEs according
  to:
                                   Podo- a
                           Pt ,k =
                                   å wi
 Submission                      Slide 218          ETRI, France Telecom, Philips, Samsung
January 2006                                doc.: IEEE 802.22-06/0005r1


        Ideal power constraint rule properties




   A: constraint area
   nmax: maximum allowed CPEs density

 A better closed-form expression of the power rule can be found later.

Submission                      Slide 219       ETRI, France Telecom, Philips, Samsung
January 2006                       doc.: IEEE 802.22-06/0005r1


                  Appendix B

 • Coexistence with other LE systems
   (Contention-Based Protocol)




Submission             Slide 220      ETRI, France Telecom, Philips, Samsung
January 2006                                       doc.: IEEE 802.22-06/0005r1
             DS Contention-Based Coexistence with LE Devices
                               (Call Flow)


               CPE                                     Primary BS


                            Normal data transmitting

                                                    Detect LE devices

                                                   Contention needed


                                                        Contention

                      Data transmitting in contention manner




Submission                             Slide 221        ETRI, France Telecom, Philips, Samsung
January 2006                                      doc.: IEEE 802.22-06/0005r1
                US Contention-Based Coexistence with LE Devices
                                  (Call Flow)


             CPE                                      Primary BS


                      Normal data transmitting




                           Detect LE devices

                                                 Contention needed
                   Contend with LE at the next TXOP


              Data transmitting in contention manner


Submission                           Slide 222         ETRI, France Telecom, Philips, Samsung

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:17
posted:8/16/2012
language:English
pages:210