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MIMO-LTE A relevant Step towards 4G

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					                   MIMO-LTE
                A relevant Step
                  towards 4G
                    Prof. Dr.-Ing. Thomas Kaiser
                                CEO
                            mimoOn GmbH



MobiMedia, August 27-29, 2007
        mimoOn is …


… a supplier of embedded
communications software
for the next generation of
MIMO-based wireless
communication standards.


Check www.mimoOn. de
Sept. 11-14, 2007:
   • MIMO-Workshop
   • MIMO Seminar
   • LTE Seminar

       “MIMO-LTE – A relevant step towards   2 / 18
       4G”, Thomas Kaiser, MobiMedia,
       August 27-29, 2007
       What means “4G” ?

Magic Mobile Future Study:                 >2 GHz BW in 2020

Edholm’s law of data rate:



                                                OFDM will come
                                                 MIMO will come




     “MIMO-LTE – A relevant step towards                  3 / 18
     4G”, Thomas Kaiser, MobiMedia,
     August 27-29, 2007
     The Future of MIMO

High-speed mobile access requires “MIMO” …

  1000 Mb/s                                                   MIMO-
                                                                 .16m
                                                          MIMO-…
  100 Mb/s                                           MIMO-LTE
                                                   MIMO-WiMAX

    10 Mb/s
                                             HSPA

     1 Mb/s                              1xEV-DO
                                UMTS
   100 kb/s                 EDGE
                    GPRS
    10 kb/s   GSM
                  2000            2005             2010          2015




   “MIMO-LTE – A relevant step towards                                  4 / 18
   4G”, Thomas Kaiser, MobiMedia,
   August 27-29, 2007
       The History of MIMO

1987 1st MIMO paper (Winters)
1991 1st MIMO patent (Paulraj)
1995 MIMO channel capacity (Telatar, Foschini, Gans)
1996 1st MIMO testbed
1999 1st MIMO prototype chip
2002 1st MIMO company
2005 1st MIMO commerc. chip
2006 MIMO breakthrough


     “MIMO-LTE – A relevant step towards          5 / 18
     4G”, Thomas Kaiser, MobiMedia,
     August 27-29, 2007
           MIMO Principles


                                                              … MIMO



… SISO                        … MISO
     Array Gain: +3dB p.D. for SIMO, MISO (PCSI), MIMO (PCSI))
     Diversity Gain: +XdB for SIMO, MISO, MIMO (CSI helps)
     Interf. Cancell. Gain: Nulling for SIMO, MISO, MIMO (all PCSI)
     Multiplexing Gain:                   for MIMO (CSI helps)

    Challenge: “Gain” Tradeoff’s under Hardware, Regulation,
                and Standardization Constraints
         “MIMO-LTE – A relevant step towards                    6 / 18
         4G”, Thomas Kaiser, MobiMedia,
         August 27-29, 2007
  Separate Frequency Flat Channels




   Tx                                 Rx




“MIMO-LTE – A relevant step towards        7 / 18
4G”, Thomas Kaiser, MobiMedia,
August 27-29, 2007
  Equivalent Parallel Channels

                  Equivalent channel




“MIMO-LTE – A relevant step towards    8 / 18
4G”, Thomas Kaiser, MobiMedia,
August 27-29, 2007
      Open Loop vs. Closed Loop




       Tx                                        Rx




Closed Loop:
                   (Diversity order max.   )

        Challenge: Low rate feedback, high mobility

    “MIMO-LTE – A relevant step towards               9 / 18
    4G”, Thomas Kaiser, MobiMedia,
    August 27-29, 2007
                     MIMO-LTE Transmitter (DL)
                                                                                                                   # of
                                        Layer
                                       Mapping                       Precoder PL                                subcarriers
                 subcarrier N                    Diversity           cyclic delay
                                        Layer
                                       Mapping
                                                 common HL
                                        Layer
                                                                     Precoder PL
                                       Mapping
                                                                     cyclic delay
                                        Layer
                                                  Diversity
                                       Mapping                                          Tx1    Tx2    Tx3     Tx4
                                                                                        IFFT   IFFT   IFFT    IFFT
                                                                                        add    add    add     add
                                        Layer
                                                                                        CP     CP     CP      CP
                                       Mapping
                 subcarrier K                    Diversity           Precoder P1
                                        Layer                        cyclic delay
                                       Mapping
                                                 common H1
                                        Layer
                                                                     Precoder P1
                                       Mapping
                 subcarrier 1                    Diversity           cyclic delay
                                        Layer
                                       Mapping


# of modulated
                                                                              # of Tx
codewords per                                          # of layers
                        one resource
  subcarrier
                            block

                                                                                        Tx1    Tx2    Tx3     Tx4
                  “MIMO-LTE – A relevant step towards                                                        10 / 18
                  4G”, Thomas Kaiser, MobiMedia,
                  August 27-29, 2007
       MIMO-LTE Receiver (DL)
                                                                                         (#antennas)            # of
                             (ST)-MIMO Detector               BL                         x 210 x 11 x 4/     subcarrier
                                                            Receive                      (0.5 / 7)ms =
                             (ST)-MIMO Detector           Beamformer                   (#antenna) x 630
                                                                                           MMACps
                                     common HL
                             (ST)-MIMO Detector               BL
                                                            Receive
                                                          Beamformer
         # of                                                                    Rx1    Rx2       Rx3      Rx4
       subcarrer                                                                 FFT     FFT      FFT      FFT
                                                                                 rem     rem     rem.      rem.
                                                                                  CP      CP      CP        CP
                             (ST)-MIMO Detector               B1
                                                            Receive
                             (ST)-MIMO Detector           Beamformer

                                     common H1
                             (ST)-MIMO Detector               B1
                                                            Receive
                             (ST)-MIMO Detector           Beamformer




# of code-words                                                        # of Rx
                   one resource                   # of layers
   (CW) per
   subcarrier          block            Detection:
                                      ~(#CW)2 x MR x                             Rx      Rx       Rx       Rx
             channel update: (once
                                        1200 MAC /
              per RB) ~ 1200 / 12 /
                                    (0.5ms/7) = (#CW)x
                                                                                 1       2        3        4
             0.5ms x MR x MT2 MAC
                                      (#CW+MR)x16,8
                = 0.2 x MR x M 2
    “MIMO-LTE – A relevant Tstep towardsMMACps                                                                11 / 18
                   MMACps
    4G”, Thomas Kaiser, MobiMedia,
    August 27-29, 2007
  MIMO-LTE Algorithms


                                      • No. of Antennas ?
                                      • X-QAM ?
                                      • Hard/Software ?




           Challenge: MIMO Detector

“MIMO-LTE – A relevant step towards               12 / 18
4G”, Thomas Kaiser, MobiMedia,
August 27-29, 2007
                       MIMO-LTE Receive Chain Requirements

                           Configuration: 2 Rx, 2 Tx, 64QAM, 100 Mbps data rate, Turbo Coding 1/3,

      #Rx = 2
      #Tx = 2                     Freq Offs              Synchroni-               631 MMACps
                                                                                  (1262 MMACps)                 16.8 MCSps
                                 Estimation                zation                                                (538 Mbps)

                                 Freq Offs               Cycl Prfx                                   De-
Rx1         RF                   Correction              Remove
                                                                                  FFT                                         269 - 538
                    2x12                                                                  2x10
                                                                                                     mux
                                                                                                                              MMACps
                                 Freq Offs               Cycl Prfx                                   De-
Rx2         RF                   Correction              Remove
                                                                                  FFT
                                                                                                     mux
 Data / Rx              30.72 MCSps           123 MMACps                28.67 MCSps
bps with Rx=2              (1.47 Gbps)        (246 MMACps)                (1.38 Gbps)
                                                                                                                        MIMO
                                                                                                  Chan Est
 CSps:   Complex Sample                                                                                                Detector
 CSps:   Complex Sample
         per second                                76.8 GACSps
 MAC:    Multiply Accumulate
 sbps:   per second second
         soft bits per Select                      (153.6 GACSps)
 ACS:    Add Compare
 Sbps:
 MAC:    Multiply per second
         soft bits Accumulate
 ACS:    Add Compare Select                                                                                              9
                                               Channel                De-Inter-          Symbol
                                     M         Decoder                 leaver      3    Demapper
                                     U
                                     X         Channel                De-Inter-          Symbol
                     100 Mbps                  Decoder                 leaver           Demapper
                                                                                                                                No ML
                                                                                                                              algorithm
  Data / Tx                              50 Mbps               100 Msbps                          16.8 MSps
                                                                                                                             for 64QAM
 bps with Tx=2                           (100 Mbps)             (600 Mbps)                         (300 Mbps)


                    “MIMO-LTE – A relevant step towards                                                                  13 / 18
                    4G”, Thomas Kaiser, MobiMedia,
                    August 27-29, 2007
        Some Results: MIMO-OFDMA
                                             2x3 MIMO-OFDMA
                                             Reuse=1, TX=10W, Isolated Cell
                                             2MHz Bandwidth
                                             Spatial Mux with 64 QAM (equiv. 4096 SISO-QAM)
                                             12dB better link budget than for SISO
                                             Iospan Wireless, San Jose Testbed, 2001
                                             Thanks to Prof. A. Paulraj (Stanford Univ.)

Ratio of
Users    0.20
among
Covered
Users    0.15



        0.10




        0

            1134      4536                 9072              13608
                         Net data rate in kb/s



      “MIMO-LTE – A relevant step towards                                       14 / 18
      4G”, Thomas Kaiser, MobiMedia,
      August 27-29, 2007
   Some Results: Cellular MIMO




                                                                     Global Evolution of UMTS/HSPA“, Dec 14, 2006
                                                                     Source: 3G americas, „Mobile Broadband: The
                 Peak rate

                  Mean rate

                  Cell edge rate
            2
 bit/s/Hz




            1




            0

                SISO               2x2 MIMO   SISO       2x2 MIMO

                  Isolated Cell               Interf. Lim. Cell


                Challenge: MIMO-Algorithm Design

“MIMO-LTE – A relevant step towards                                 15 / 18
4G”, Thomas Kaiser, MobiMedia,
August 27-29, 2007
  MIMO-Femtocell-Scenario


                                      MIMO is well-suited
                                      for “contained”
                                      environments
                                      100 Mbit/s feasible
                                      with femtocells
                                      MIMO-Femtocells
                                      similar to
                                      MIMO-WLAN



“MIMO-LTE – A relevant step towards              16 / 18
4G”, Thomas Kaiser, MobiMedia,
August 27-29, 2007
                     MIMO-LTE vs MIMO-WLAN

                                MIMO preLTE         pre802.11n

  Modulation technique              OFDM               OFDM
                                                                                                   MIMO 2x2
                                  SFBC, SM,          SFBC, SM,                                     SISO
       MIMO mode
                                 Beamforming        Beamforming
                                   Scalable            Fixed
    System Bandwidth
                                1.25 ~ 20 MHz         20 MHz
                                  128 ~ 2048 /          64 /
FFT and Subcarrier Spacing
                                    15 kHz           312.5 kHz
    Access technology              OFDMA             CSMA/CA
         Services              Packet data, VoIP     Packet data
           QoS                   Good support       Weak support
Theoretical peak bit rate in   100 (DL) / 50 (UL)
                                                    > 200 Mbps
        ideal case                   Mbps
   Latency (round trip)              10 ms             < 5 ms
                                                                   Source: „Throughput of a MIMO OFDM based
         Coverage               2.8 km ~ 7.4 km     30 m ~ 100 m   WLAN system“, T. Schenk et. al., IEEE S
                                                                   CVT2004, Gent, Belgium, Nov. 2004



                  “MIMO-LTE – A relevant step towards                                            17 / 18
                  4G”, Thomas Kaiser, MobiMedia,
                  August 27-29, 2007
      Conclusion

MIMO represents an economical way to
           … to increase user capacity
           … to increase coverage
           … to increase cell throughput

   “… the potential of using the spatial domain is large
   and the development of new and even more efficient
   multi-antenna algorithms is expected to continue in
   the future.”
            Source: 3G americas, „Mobile Broadband: The
            Global Evolution of UMTS/HSPA“, Dec 14, 2006

    “MIMO-LTE – A relevant step towards                    18 / 18
    4G”, Thomas Kaiser, MobiMedia,
    August 27-29, 2007

				
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Description: 3G Long Term Evolution is the evolution of the project, began in Toronto in 2004 3GPP meeting. LTE is not 4G technology is widely misunderstood, but between 3G and 4G technology as a transition, is the global standard for 3.9G, 3G is to improve and enhance air access technology, using OFDM and MIMO for its wireless network evolution the only criterion. 20MHz of spectrum in the downlink bandwidth to deliver 326Mbit / s and uplink 86Mbit / s peak rate. Improve the performance of cell edge users, increase cell capacity and reducing system latency.