www.ieee802.org16tgmcontribC80216m-09_0676.ppt by yurtgc548

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									                                          Mapping rule for Constellation Rearrangement
IEEE 802.16 Presentation Submission Template (Rev. 9)
Document Number:
   IEEE C802.16m-09/0676
Date Submitted:
   2009-03-08
Source:
   Hyungho Park, Sukwoo Lee                                                                     Voice:           +82-31-450-1934

   LG Electronics, Inc.                                                                      E-mail:hyunghopark@lge.com, sugoo@lge.com
   LG R&D Complex, 533 Hogye-1dong,
   Dongan-gu, Anyang, 431-749, Korea
   *<http://standards.ieee.org/faqs/affiliationFAQ.html>

Venue: IEEE 802.16m Session#60, Vancouver, Canada

Re: IEEE 802.16m-09/0012, “Call for Comments on Amendment Working Document”
   Target topic: “Channel Coding & HARQ” Section

Purpose: To provide details on mapping rule for constellation rearrangement and text proposal for the amendment text

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                       CoRe version design

•   Design method for Constellation Rearrangement version

    – CoRe related descriptions in current SDD text
     “ The CoRe can be expressed by a bit-level interleaver within a tone.”

    – CoRe version should be designed with consideration of bit-level
      interleaver within a symbol and across symbols within a tone.
        • Bit-level interleaving within a QAM symbol : averaging out bit reliability difference
          between component bits within a symbol (swapping MSB with LSB)
        • Bit-level interleaving of inter-symbols within a tone: to exploit spatial diversity gain


    – The starting position is determined as SPID function in unit of 2 QAM
      symbols
    Performance gain from bit-swapping between
           two symbols within a tone [1]
•   Swapping between two symbols within a tone
          • 16 QAM                                                             64 QAM




–   Simulation assumption: ½ CTC, VEHA 30km/h, MMSE receiver. 2x2 SM, distributed LRU, Max Tx: 2
–   In simulation results, legend N bit (I:A, Q:B) means that A-bit of In-phase part and B-bit of Quadrature-
    phase part are swapped between two symbols within a tone to exploit extra spatial gain.
–   From simulation results, we can know that bitwise swapping has better performance than symbol-wise
    swapping.
    Performance gain from bit-swapping between
           two symbols within a tone [2]

•   Performance evaluation in HARQ retransmission
–   Bit interleaving within a QAM symbol is excluded to survey on the impact of spatial
    mapping with increased retransmission number (vertical mapping)

                                                          mapping rule applied in simulation
                                                      CoRe version         Mapping rule (64 QAM)
                                                         (CRV)
                                                                        Symbol 1          Symbol 2
                                                           0
                                                           1




–   In case of 64 QAM, it’s the best mapping rule that SB of first spatial stream is
    swapped with SB of second spatial stream in the aspect of performance and
    complexity.
     Details of mapping rule for CoRe version [1]
•   Mapping rule
        • Two CoRe versions




        • Proposed mapping rules are designed in the aspect of average performance gain
          for maximum retransmission.
        • Proposed mapping rule is enabled to deploy with low implementation complexity.
    Details of mapping rule for CoRe version [2]

•   Mapping operation with 2 CoRe versions in retransmission
        • 16 QAM




          64 QAM
    Details of mapping rule for CoRe version [3]

•   Clean separation from MIMO configuration
    - After bit-interleaving of two symbols within a tone, the resulted symbols are fed to time-
    frequency resource
    - Regardless of the number of rank, CoRe is applied in a unit of two symbols within a tone. Paired
    two symbols with CoRe are mapped to time-frequency resource unit without any impact to the
    corresponding MIMO modes
                Performance evaluation [1]

•   Simulation Parameters


                          Parameters                    Assumption
                           Bandwidth                       10 MHz
                      Number of subcarrier                  1024
                          Frame length                      5ms
                       Channel estimation                  Perfect
                      Channel code/HARQ              CTC ½ / Chase, IR
                           Modulation              QPSK, 16 QAM, 64 QAM
                       MIMO configuration                 2 x 2 SM
                       Resource allocation           Distributed resource
                                                           allocation
                         Channel model                 PEDB, VEH A
                          MS mobility                  3km/h,120km/h
                         Receiver type                  Linear MMSE
                Maximum number of retransmission             1~4
                     Retransmission latency                 10ms
         Performance evaluation [2]


– Chase HARQ




  0.2 dB gain over 16e @ 10% FER
         Performance evaluation [3]


– Chase HARQ




   2.6 dB gain over 16e @ 10% FER
         Performance evaluation [4]


– Chase HARQ




   4.7 dB gain over 16e @ 10% FER
            Performance evaluation [5]


– IR-HARQ




1.0 dB (Max. Tx 2) & 1.3 dB (Max. Tx 4) gain over 16e @ 10% FER
            Performance evaluation [6]

– IR-HARQ




  1.2 dB (Max. Tx 2) & 0.8 dB (Max. Tx 4) gain over 16e @ 10% FER
            Performance evaluation [7]

– IR-HARQ




  3.1 dB (Max. Tx 2) & 4.2 dB (Max. Tx 4) gain over 16e @ 10% FER
            Performance evaluation [8]

– IR-HARQ




  3.3 dB (Max. Tx 2) & 4.2 dB (Max. Tx 4) gain over 16e @ 10% FER
                           Conclusion
•   Adopt the following text proposal including mapping rule with 2
    CoRe versions into Section 15.x.2.2. (Constellation Rearrangement) of
    the Amendment text as in IEEE 802.16m-09/0010

								
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