Investigation on 1024 QAM feasibility in 11ax Month Year doc.: IEEE 802.11-yy/xxxxr0 May 2014 Investigation on 1024 QAM feasibility in 11ax Date: 2014-05-12 Authors: Name Affiliations Address Phone Email Eunsung Park LG Electronics 19, Yangjea-daero 11gil, Seocho-gu, Seoul 137-130, Korea esung.park@lge.com Wookbong Lee wookbong.lee@lge.com Jinsoo Choi js.choi@lge.com Jinyoung Chun jiny.chun@lge.com Dongguk Lim dongguk.lim@lge.com HanGyu Cho hg.cho@lge.com Eunsung Park, LG Electronics John Doe, Some Company

Motivation (1/2) Based on PAR [1] Based on observation May 2014 Motivation (1/2) Based on PAR [1] Main goal of 11ax is to “at least four times improvement in the average throughput per station”. Based on observation In most indoor scenarios, STAs transmit with the highest MCS level. MCS portion in Scenario1 (See Appendix A for simul. parameters.) MCS0 MCS1 MCS2 MCS3 MCS4 MCS5 MCS6 MCS7 MCS8 MCS9 DL [%] 2 98 UL [%] 1 9 83 Eunsung Park, LG Electronics

May 2014 Motivation (2/2) 1024 QAM provides 25% additional spectral efficiency compared to 256 QAM. However, the spectral efficiency gain in link-level by 1024 QAM does not guarantee average throughput gain in system-level. Key Question: “How much system-level gain can be obtained by adopting 1024 QAM in 11ax?” Eunsung Park, LG Electronics

Link curve including 1024 QAM May 2014 Link curve including 1024 QAM Two additional MCSs for 1024 QAM MCS 10 : 1024QAM with 3/4 code rate MCS 11 : 1024QAM with 5/6 code rate MCS 11 requires about 32dB SNR for PER of 10%. (Gray mapped constellation in Appendix B, BCC with a random interleaver) Eunsung Park, LG Electronics

Simulation Environments May 2014 Simulation Environments Simulation parameters are described in Appendix A. We simulate for SISO and 2 by 2 MIMO with space time block code (STBC) and spatial multiplexing (SM). In each simulation scenario [2] with 1024 QAM, we will investigate MCS portion selected for data transmission Average throughput gain Detailed simulation results are presented in Appendix C, D and E. Eunsung Park, LG Electronics

Simulation Results: MCS Portion May 2014 Simulation Results: MCS Portion Residential Enterprise Indoor hotspot Outdoor SISO In indoor scenarios, 1024 QAM MCS levels are selected with high probability. STBC SM Eunsung Park, LG Electronics

Simulation Results: Average Throughput Gain May 2014 Simulation Results: Average Throughput Gain • In most indoor scenarios, 1024 QAM provides average throughput gain over 20% compared to the case without 1024 QAM. Average Throughput Gain by including 1024 QAM [Unit : %] Residential Enterprise Indoor hotspot Outdoor DL UL SISO 22 18 25 21 20 11 1 STBC 24 12 2 SM 13 14 3 5 Eunsung Park, LG Electronics

Hardware Feasibility (1/2) May 2014 Hardware Feasibility (1/2) 1024 QAM lowers the minimum allowed constellation error (EVM) below -38dB. 6dB tighter than the minimum value of 11ac (-32dB for MCS9). Modulation Coding rate Allowed constellation error [dB] BPSK 1/2 -5 QPSK -10 3/4 -13 16 QAM -16 -19 64 QAM 2/3 -22 -25 5/6 -27 256 QAM -30 -32 1024 QAM -36 -38 Eunsung Park, LG Electronics

Hardware Feasibility (2/2) May 2014 Hardware Feasibility (2/2) Need to mainly check on the following issues. Feasibility becomes higher by the time when 11ax is in the market around 2018. Hardware Issues Feasibility Power amplifier (PA) Non-linearity One of the most challenging issues PA supporting 1024 QAM is already feasible in wired broadcasting system. Need to check if it is feasible in wireless system due to its lack of power Analog to digital converter (ADC) Quantization error Current ADC technology and more advancement seem to make it feasible. Local oscillator / synthesizer Phase noise I/Q imbalances This feasibility can be checked together with ADC feasibility since the error here is combined with ADC output. Eunsung Park, LG Electronics

Conclusions We showed that May 2014 Conclusions We showed that In indoor scenarios, 1024 QAM provides system-level gain of 10 ~ 20 % even in 2 by 2 MIMO with SM. The gain is increasing in SISO and STBC. It is also important that from the user perspective, 1024 QAM provides 25% peak data rate increase as well as average throughput enhancement. We propose to check hardware feasibility to meet the lower EVM requirement. Eunsung Park, LG Electronics

May 2014 References [1] 11-14-0165-01-0hew-802-11-hew-sg-proposed-par [2] 11-13-1001-08-0hew-simulation-scenarios-document-template [3] 11-14-0082-00-0hew-improved-spatial-reuse-feasibility-part-i Eunsung Park, LG Electronics

May 2014 Appendices Eunsung Park, LG Electronics

Appendix A. Simulation Parameters May 2014 Appendix A. Simulation Parameters Simulation scenario Scenario1 Scenario2 Scenario3 Scenario4 AP/STA power [dBm] 23 / 17 24 / 21 17 / 15 30 / 15 # of users per BSS 5 32 30 50 Run time Initial: 10s, simulation: 10s, drop: 5 BW 40MHz (128 FFT) Data size 1ms TXOP less fixed overhead (RTS/CTS off) Normal overhead: SIFS + ACK + 2*PLCP header GI Long (0.8 us) # of AP/STA antennas Rank1: SISO(1,1)/Alamouti(2,2), Rank2: SM(2,2) (interference model: AWGN) Max # of retries Scenario1: 4, other scenarios: 10 DL & UL traffic Full buffer (DL & UL ratio: based on PHY system simulation in [2]) CCA level Preamble detection: -82dBm (both AP and STA) Energy detection: -62dBm (both AP and STA) Channel Time-varying Target PER 0.1 PHY abstraction Capacity based method MCS selection Genie method Eunsung Park, LG Electronics

Appendix B. 1024QAM Constellation May 2014 Appendix B. 1024QAM Constellation 01111 01110 01100 01101 01001 01000 01010 01011 00011 00010 00000 00001 00101 00100 00110 00111 10111 10110 10100 10101 10001 10000 10010 10011 11011 11010 11000 11001 11101 11100 11110 11111 Eunsung Park, LG Electronics

Appendix C. Simulation Results for SISO (1) May 2014 Appendix C. Simulation Results for SISO (1) Scenario 1 MCS Portion Scenario 1 MCS0 MCS1 MCS2 MCS3 MCS4 MCS5 MCS6 MCS7 MCS8 MCS9 MCS10 MCS11 Down-link w/o 1024 QAM [%] 2 98 - w/ 1024 QAM [%] 1 96 Up-link 9 83 4 77 Eunsung Park, LG Electronics

Appendix C. Simulation Results for SISO (2) May 2014 Appendix C. Simulation Results for SISO (2) Scenario 2 MCS Portion Scenario 2 MCS0 MCS1 MCS2 MCS3 MCS4 MCS5 MCS6 MCS7 MCS8 MCS9 MCS10 MCS11 Down-link w/o 1024 QAM [%] 100 - w/ 1024 QAM [%] Up-link 2 98 1 95 Eunsung Park, LG Electronics

Appendix C. Simulation Results for SISO (3) May 2014 Appendix C. Simulation Results for SISO (3) Scenario 3 MCS Portion Scenario 3 MCS0 MCS1 MCS2 MCS3 MCS4 MCS5 MCS6 MCS7 MCS8 MCS9 MCS10 MCS11 Down-link w/o 1024 QAM [%] 3 1 96 - w/ 1024 QAM [%] 2 91 Up-link 4 20 64 14 5 45 Eunsung Park, LG Electronics

Appendix C. Simulation Results for SISO (4) May 2014 Appendix C. Simulation Results for SISO (4) Scenario 4 MCS Portion Scenario 4 MCS0 MCS1 MCS2 MCS3 MCS4 MCS5 MCS6 MCS7 MCS8 MCS9 MCS10 MCS11 Down-link w/o 1024 QAM [%] 19 3 6 4 2 12 43 - w/ 1024 QAM [%] 7 33 Up-link 51 5 9 8 1 Eunsung Park, LG Electronics

Appendix C. Simulation Results for SISO (5) May 2014 Appendix C. Simulation Results for SISO (5) Without 1024 QAM With 1024 QAM DL Tput [Mbps] UL Tput PER Res. PER Scenario1 22.4 32.7 2.81e-02 1.38e-03 27.4 + 22% 38.5 + 18% 4.07e-02 1.83e-03 Scenario2 14.2 26.8 9.60e-03 1.49e-04 17.7 + 25% 32.5 + 21% 1.99e-02 3.13e-04 Scenario3 4.20 12.9 5.55e-02 6.45e-04 5.05 + 20% 14.3 + 11% 6.81e-02 5.60e-04 Scenario4 16.5 23.0 1.89e-01 1.22e-02 18.3 23.2 + 1% Eunsung Park, LG Electronics

Appendix D. Simulation Results for STBC (1) May 2014 Appendix D. Simulation Results for STBC (1) Scenario 1 MCS Portion Scenario 1 MCS0 MCS1 MCS2 MCS3 MCS4 MCS5 MCS6 MCS7 MCS8 MCS9 MCS10 MCS11 Down-link w/o 1024 QAM [%] 100 - w/ 1024 QAM [%] 1 99 Up-link 3 96 2 91 Eunsung Park, LG Electronics

Appendix D. Simulation Results for STBC (2) May 2014 Appendix D. Simulation Results for STBC (2) Scenario 2 MCS Portion Scenario 2 MCS0 MCS1 MCS2 MCS3 MCS4 MCS5 MCS6 MCS7 MCS8 MCS9 MCS10 MCS11 Down-link w/o 1024 QAM [%] 100 - w/ 1024 QAM [%] Up-link 1 99 Eunsung Park, LG Electronics

Appendix D. Simulation Results for STBC (3) May 2014 Appendix D. Simulation Results for STBC (3) Scenario 3 MCS Portion Scenario 3 MCS0 MCS1 MCS2 MCS3 MCS4 MCS5 MCS6 MCS7 MCS8 MCS9 MCS10 MCS11 Down-link w/o 1024 QAM [%] 100 - w/ 1024 QAM [%] 1 98 Up-link 9 2 88 15 8 65 Eunsung Park, LG Electronics

Appendix D. Simulation Results for STBC (4) May 2014 Appendix D. Simulation Results for STBC (4) Scenario 4 MCS Portion Scenario 4 MCS0 MCS1 MCS2 MCS3 MCS4 MCS5 MCS6 MCS7 MCS8 MCS9 MCS10 MCS11 Down-link w/o 1024 QAM [%] 13 2 3 5 6 4 12 51 - w/ 1024 QAM [%] 7 40 Up-link 36 10 14 1 Eunsung Park, LG Electronics

Appendix D. Simulation Results for STBC (5) May 2014 Appendix D. Simulation Results for STBC (5) Without 1024 QAM With 1024 QAM DL Tput [Mbps] UL Tput PER Res. PER Scenario1 22.9 35.3 8.36e-03 7.58e-06 28.5 + 24% 43.0 + 22% 1.61e-02 1.53e-05 Scenario2 14.3 27.4 6.32e-04 0.00 17.9 + 25% 34.1 2.91e-03 9.53e-06 Scenario3 4.26 14.6 3.29e-02 1.73e-05 5.28 16.6 + 12% 5.25e-02 5.31e-05 Scenario4 19.3 1.63e-01 7.84e-03 21.6 34.8 + 2% 1.64e-01 7.85e-03 Eunsung Park, LG Electronics

Appendix E. Simulation Results for SM (1) May 2014 Appendix E. Simulation Results for SM (1) Scenario 1 MCS Portion Scenario 1 MCS0 MCS1 MCS2 MCS3 MCS4 MCS5 MCS6 MCS7 MCS8 MCS9 MCS10 MCS11 Down-link w/o 1024 QAM [%] 2 98 - w/ 1024 QAM [%] 3 1 94 Up-link 14 75 11 5 59 Eunsung Park, LG Electronics

Appendix E. Simulation Results for SM (2) May 2014 Appendix E. Simulation Results for SM (2) Scenario 2 MCS Portion Scenario 2 MCS0 MCS1 MCS2 MCS3 MCS4 MCS5 MCS6 MCS7 MCS8 MCS9 MCS10 MCS11 Down-link w/o 1024 QAM [%] 1 3 94 - w/ 1024 QAM [%] 4 2 88 Up-link 12 76 10 62 Eunsung Park, LG Electronics

Appendix E. Simulation Results for SM (3) May 2014 Appendix E. Simulation Results for SM (3) Scenario 3 MCS Portion Scenario 3 MCS0 MCS1 MCS2 MCS3 MCS4 MCS5 MCS6 MCS7 MCS8 MCS9 MCS10 MCS11 Down-link w/o 1024 QAM [%] 1 2 4 3 16 69 - w/ 1024 QAM [%] 12 7 50 Up-link 6 9 24 20 8 Eunsung Park, LG Electronics

Appendix E. Simulation Results for SM (4) May 2014 Appendix E. Simulation Results for SM (4) Scenario 4 MCS Portion Scenario 4 MCS0 MCS1 MCS2 MCS3 MCS4 MCS5 MCS6 MCS7 MCS8 MCS9 MCS10 MCS11 Down-link w/o 1024 QAM [%] 44 5 6 8 7 4 2 10 1 13 - w/ 1024 QAM [%] Up-link 80 3 Eunsung Park, LG Electronics

Appendix E. Simulation Results for SM (5) May 2014 Appendix E. Simulation Results for SM (5) Without 1024 QAM With 1024 QAM DL Tput [Mbps] UL Tput PER Res. PER Scenario1 44.6 62.6 3.98e-02 5.42e-04 53.9 + 21% 70.9 +13% 5.84e-02 6.17e-04 Scenario2 27.7 47.5 3.62e-02 2.61e-04 33.2 + 20% 54.2 +14% 5.39e-02 3.51e-04 Scenario3 7.39 17.8 7.09e-02 1.63e-04 8.36 + 13% 18.4 + 3% 7.14e-02 2.70e-04 Scenario4 18.0 17.2 2.56e-01 2.50e-02 18.9 + 5% + 0% Eunsung Park, LG Electronics

Appendix F. Simulation Results in Scenario 1 with High CCA Level (1) May 2014 Appendix F. Simulation Results in Scenario 1 with High CCA Level (1) We compare the performance between with and without 1024 QAM in Scenario 1 by setting CCA level to -60dB as shown in [3]. SISO MCS Portion SISO MCS0 MCS1 MCS2 MCS3 MCS4 MCS5 MCS6 MCS7 MCS8 MCS9 MCS10 MCS11 Down-link w/o 1024 QAM [%] 2 1 3 4 12 71 - w/ 1024 QAM [%] 7 61 Up-link 10 8 6 18 38 27 Eunsung Park, LG Electronics

Appendix F. Simulation Results in Scenario 1 with High CCA Level (1) May 2014 Appendix F. Simulation Results in Scenario 1 with High CCA Level (1) STBC MCS Portion STBC MCS0 MCS1 MCS2 MCS3 MCS4 MCS5 MCS6 MCS7 MCS8 MCS9 MCS10 MCS11 Down-link w/o 1024 QAM [%] 1 2 7 87 - w/ 1024 QAM [%] 6 3 78 Up-link 5 4 18 57 11 41 Eunsung Park, LG Electronics

Appendix F. Simulation Results in Scenario 1 with High CCA Level (1) May 2014 Appendix F. Simulation Results in Scenario 1 with High CCA Level (1) SM MCS Portion SM MCS0 MCS1 MCS2 MCS3 MCS4 MCS5 MCS6 MCS7 MCS8 MCS9 MCS10 MCS11 Down-link w/o 1024 QAM [%] 2 1 5 7 3 21 52 - w/ 1024 QAM [%] 12 35 Up-link 6 8 13 18 10 Eunsung Park, LG Electronics

Appendix F. Simulation Results in Scenario 1 with High CCA Level (1) May 2014 Appendix F. Simulation Results in Scenario 1 with High CCA Level (1) The additional MCS levels offer a throughput gain even in the case with high CCA level. Without 1024 QAM With 1024 QAM DL Tput [Mbps] UL Tput PER Res. PER SISO 36.8 39.7 7.94e-02 4.45e-03 42.2 + 15% 43.0 + 8% 8.97e-02 3.95e-03 STBC 41.5 49.3 5.33e-02 4.41e-04 49.2 + 19% 54.6 + 11% 6.78e-02 4.42e-04 SM 66.5 61.8 9.76e-02 2.44e-03 72.7 + 9% 64.3 + 4% 1.03e-01 2.17e-03 Eunsung Park, LG Electronics