1 / 30

LDPC Tone Mapping for IEEE 802.11aj(45GHz)

LDPC Tone Mapping for IEEE 802.11aj(45GHz). Date: December 21, 2019 Presenter: Haiming WANG. Authors/contributors:. Abstract. This presentation describes LDPC tone mapping mechanism for IEEE 802.11aj(45GHz)

mdurham
Download Presentation

LDPC Tone Mapping for IEEE 802.11aj(45GHz)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. LDPC Tone Mapping for IEEE 802.11aj(45GHz) Date: December 21, 2019 Presenter: Haiming WANG Authors/contributors: Shiwen He, Haiming Wang, et al. (SEU/CWPAN)

  2. Abstract • This presentation describes LDPC tone mapping mechanism for IEEE 802.11aj(45GHz) • Using the proposed LDPC tone mapping mechanism, the performance can be improved up to 4.2dB Shiwen He, Haiming Wang, et al. (SEU/CWPAN)

  3. In 11n, interleaving is not needed for LDPC, since one 1944-bit LDPC codeword covers almost all streams and tones within an OFDM symbol. LDPC has an intrinsic pseudo-randomness property that protects against burst errors. In 11ac/ad/af, tone mapping is used for LDPC, since multiple streams and/or high MCSs lead to large NCBPS , so the coded bits from one LDPC codeword are transmitted only through a fraction of the toneswhen LCW < NCBPS , and the full frequency diversity would not be achieved. Introduction Notes: NCBPS means the number of code bits per OFDM symbols, LCW means the length of one LDPC codeword Shiwen He, Haiming Wang, et al. (SEU/CWPAN)

  4. by discretizing the burst errors, tone mapping can protect against burst errors, and overcome frequency selective fading better At the receiver, tone mapping can be implemented as part of the FFT block, with no additional delay LDPC tone mapping distance in 11af, 11ad and 11ac for 11ad, DTM is 2/3 for 16QAM/64QAM for 11ac, DTM is 4/6/6/9 for 20/40/80/160MHz for 11af, DTMis 8/9 for 2/4 segment operation Introduction Shiwen He, Haiming Wang, et al. (SEU/CWPAN)

  5. LDPC tone mapping could be used like 802.11ac, for each stream, map consecutive QAM symbols to data tones which are separated by at least DTM -1 other data tones where Tone Mapping Mechanism(1/2) Notes: DTM means LDPC tone mapping distance, NSD means the total number of data subcarriers, NSS,u means the number of streams for user u, Nuser means the number of users Shiwen He, Haiming Wang, et al. (SEU/CWPAN)

  6. Tone Mapping Mechanism(2/2) • Using a block-interleavingmatrix with DTMrows and NSD /DTM • columnsfor every OFDM symbol at each stream, tone mapping can be • implemented by writing row-wiseand reading back • column-wise • Example: BW=540MHz,NSD =168, DTM =8, NSD /DTM =21, NSS =1 Write Read Shiwen He, Haiming Wang, et al. (SEU/CWPAN)

  7. Tone Mapping Distance(1/3) • Procedure for choosing optimal DTM • For each bandwidth, it would be desirable to have a DTMwhich is • at least as large as , so that one LDPC codeword covers the full range of tones • an integer divisor of the number of subcarriers, NSD • constant over all rates within each bandwidth, so that the tone de-mapper • can be implemented at Rx in the FFT block with fixed tone processing Shiwen He, Haiming Wang, et al. (SEU/CWPAN)

  8. Possible parameters For BW= 540MHz, NSD = 168, NSS= 4, Modulation= 64QAM, NCBPS/LCW= 168*6*4/672=6, so possible values for DTM are: 6,7,8,12,14,21,24,28,42,56,84 For BW= 1080MHz,NSD= 336, NSS= 4, Modulation= 64QAM, NCBPS/LCW= 336*6*4/672=12, so possible values for DTM are: 12,14,21,24,28,42,48,56,84,112,168 For each simulation, the best twoDTMvalues are selected into optional parameter set, and the first/second element in the set is the best/second best parameter Tone Mapping Distance(2/3) Shiwen He, Haiming Wang, et al. (SEU/CWPAN)

  9. For each BW, the intersection set of the optional parameter sets will be achieved For each BW, the element in intersection which leads to best performance for most simulation situations is proposed to be the optimal DTM Tone Mapping Distance(3/3) Shiwen He, Haiming Wang, et al. (SEU/CWPAN)

  10. Simulation Setup • Channel model: Conference Room • Number of distinguishable paths : 12 • Packet length: 4096 bytes • LDPC codeword length: 672bits • Number of channel realizations: 5000 • Simulation antennas: 1x1, 2x2, 4x4 for 1, 2, 4ss, respectively • Modulation and code rate: {BPSK ½},{QPSK ½},{16QAM ½}, • {64QAM ½} Shiwen He, Haiming Wang, et al. (SEU/CWPAN)

  11. Simulation Results(1/2) • Proposed optional parameter set • For 540MHz • For 1080MHz • Notes: Since the performances of all DTM s for low-order modulations are very close, so their optional parameters sets could be ignored which are marked as “\” in the table. Shiwen He, Haiming Wang, et al. (SEU/CWPAN)

  12. Simulation Results(2/2) • Base on the results above, we can get the intersection for 540MHz and 1080MHz • Appendix-A gives simulation results for DTMwith bandwidth 540MHz • Appendix-B gives simulation results for DTMwith bandwidth 1080MHz Shiwen He, Haiming Wang, et al. (SEU/CWPAN)

  13. LDPC tone mapping should be used for OFDM in IEEE 802.11aj (45GHz) Optimal DTM for LDPC tone mapping in 802.11aj Conclusions Shiwen He, Haiming Wang, et al. (SEU/CWPAN)

  14. Reference [1] “11-10-1300-00-00ac-ldpc-for-11ac”, Jun Zheng et al. [2] “11-11-0428-00-00ac-proposed-correction-of-ldpc-tone-mapping-equation”, Hossein Taghavi et al. [3] “11-12-0839-00-00af-interleaver-parameters”,Ron Porat et al. [4] “Draft P802.11ad_D9.0” [5] “ Draft P802.11ac_D5.1” Shiwen He, Haiming Wang, et al. (SEU/CWPAN)

  15. APPENDIX A: Simulation Results for 540MHz Shiwen He, Haiming Wang, et al. (SEU/CWPAN)

  16. 2 dB gain Optional parameter set is {6,7} Shiwen He, Haiming Wang, et al. (SEU/CWPAN)

  17. 2.2 dB gain Optional parameter set is {6,7} Shiwen He, Haiming Wang, et al. (SEU/CWPAN)

  18. Optional parameter set is {7,6} 2 dB gain Shiwen He, Haiming Wang, et al. (SEU/CWPAN)

  19. Optional parameter set is {6,7} 0.7 dB gain Shiwen He, Haiming Wang, et al. (SEU/CWPAN)

  20. 3 dB gain Optional parameter set is {6,7} Shiwen He, Haiming Wang, et al. (SEU/CWPAN)

  21. Optional parameter set is {7,6} 2 dB gain Shiwen He, Haiming Wang, et al. (SEU/CWPAN)

  22. APPENDIX B: Simulation Results for 1080MHz Shiwen He, Haiming Wang, et al. (SEU/CWPAN)

  23. Optional parameter set is {14,12} 2 dB gain Shiwen He, Haiming Wang, et al. (SEU/CWPAN)

  24. Optional parameter set is {14,12} 4 dB gain Shiwen He, Haiming Wang, et al. (SEU/CWPAN)

  25. Optional parameter set is {12,14} 4 .2dB gain Shiwen He, Haiming Wang, et al. (SEU/CWPAN)

  26. 4 dB gain Optional parameter set is {14,12} Shiwen He, Haiming Wang, et al. (SEU/CWPAN)

  27. Optional parameter set is {12,14} 1.8 dB gain Shiwen He, Haiming Wang, et al. (SEU/CWPAN)

  28. Optional parameter set is {12,14} 3.5 dB gain Shiwen He, Haiming Wang, et al. (SEU/CWPAN)

  29. Optional parameter set is {12,14} 3.5 dB gain Shiwen He, Haiming Wang, et al. (SEU/CWPAN)

  30. Thanks for Your Attention! Shiwen He, Haiming Wang, et al. (SEU/CWPAN)

More Related