System Level Performance Evaluation on Multiplexing of USCCH in IEEE 802.16m IEEE 802.16 Presentation Submission Template (Rev. 9) Document Number: IEEE C802.16m-08/671r1 Date Submitted: 2008-07-16 Source: Hyunkyu Yu, Jaeweon Cho, Taeyoung Kim, Mihyun Lee, Jeongho Park, Heewon Kang, Hokyu Choi , Rakesh Taori Samsung Electronics hk.yu@samsung.com, jaeweon.cho@samsung.com Yi Hsuan, Ping Wang, Hujun Yin Intel Corporation yi.hsuan@intel.com, ping.wang@intel.com, hujun.yin@intel.com Jun Yuan, Sophie Vrzic, Dongsheng Yu, Mo-Han Fong, Robert Novak, Hosein Nikopourdeilami, Kathiravetpillai Sivanesan, Sang-Youb Kim Nortel Networks junyu@nortel.com, svrzic@nortel.com, mhfong@nortel.com Sungcheol Chang, Hyun Lee scchang@etri.re.kr ETRI Venue: IEEE 802.16m-08/024, “Call for Comments and Contributions on Project 802.16m System Description Document (SDD)”. Target topic: “DL Control Structure”. 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System Level Performance Evaluation on Multiplexing of USCCH in IEEE 802.16m Hyunkyu Yu, Jaeweon Cho, Taeyoung Kim, Mihyun Lee, Jeongho Park, Heewon Kang, Hokyu Choi, Rakesh Taori Samsung Electronics Yi Hsuan, Ping Wang, Hujun Yin Intel Corporation Jun Yuan, Sophie Vrzic, Dongsheng Yu, Mo-Han Fong, Robert Novak, Hosein Nikopourdeilami, Kathiravetpillai Sivanesan, Sang-Youb Kim Nortel Networks Sungcheol Chang, Hyun Lee ETRI July, 2008 Multiplexing of USCCH and Data Options (1) FDM (2) TDM (3) Hybrid FDM/TDM Proposed Scheme FDM Rationale: Gain over TDM • Data throughput gain: 6~30% • Capacity (# of supportable users) gain: > 80% Annex 1, 2, 3 • Link level performance gain Proposed Change to SDD Text • Within a sub-frame, control and data channels are multiplexed using FDM. Both control and data channels are transmitted on logical resource units (LRU) that span all OFDM symbols in a sub-frame. Why FDM is better than TDM? More efficient Power Sharing Higher Throughput Efficient power sharing Better Granularity Smaller Resource Loss Control IE #1 Control IE #2 Control IE #3 TDM Control • TDM: Power sharing within USCCH only FDM Small Granularity possible IE #3 Control IE #2 Control IE #1 • FDM: Power sharing between Data and USCCH No power sharing • FDM: E.g. 108 tones (1 SubCH x 6 symbol) • TDM: E.g. 864 tones (48 SubCHs x 1 symbol) Resource Large loss Granularity Annex 1: System Level Performance Evaluation on Multiplexing of USCCH in IEEE 802.16m Hyunkyu Yu, Taeyoung Kim, Mihyun Lee, Jeongho Park, Jaeweon Cho, Heewon Kang, Hokyu Choi Samsung Electronics Co., Ltd. FDM vs. TDM Performance Metrics GRANULARITY of Ratio btw FDM TDM Control and Data (1-D MAP region) HIGHER Lower (especially for short-length sub-frame) COVERAGE (Outage) BETTER Worse SPECTRAL EFFICEINCY BETTER Worse BETTER Worse (Sector Throughput) CHANNEL ESTIMATION Shorter Processing Time (Latency) Longer TRADE-OFF between CH. est. performance and benefit of latency Support Power Saving: Micro-sleep (in one Sub-frame) Not support TRADE-OFF between CH. est. performance and benefit of micro-sleep NOT significant gain within a sub-frame (<3%) [Annex] Comparisons btw TDM and FDM (1) Performance Metric • With fixed orthogonal resource overhead, How many users can be supported with satisfying MAP outage requirement (<3%)? • MAP outage is controlled by ∆MARGIN Availability (%) = 100 – MAP outage 100 100.0 100.0 98.61 97.47 MUX Orthogonal Resource Overhead FDM 16.7% TDM 16.7% (1 OFDMA symbol) 97% *16.7%: Enable to support Maximum DL8 UL8 assignment blocks AVAILABILITY (%) 95 89.37 90 87.20 TDM 85 • Even if ∆MARGIN is increased, TDM cannot support more than DL3, UL3 users 80 75 70 6 9 DELTAMARGIN (dB) FDM: DL 8 UL 8 users 6 9 6 9 DELTAMARGIN (dB) DELTAMARGIN (dB) TDM: DL 3 UL 3 users TDM: DL 4 UL 4 users FDM • Enable to support DL8, UL8 users without change of resource OH Comparisons btw TDM and FDM (2) Performance Metric • Maximum SECTOR THROUGHPUT with satisfying MAP outage requirement (<3%) MUX • GRANULALITY of resource ratio between data and control • FDM: Resource + Power (SOFT Separation) FDM SECTOR THROUGHPUT (Mbps) • TDM: Resource (HARD Separation) 8.0 TDM 7.0 # of Users (DL, UL) Orthogonal Resource Overhead ∆MARGIN (2, 2) 8.3% 6dB (3, 3) 8.3% 5dB (4, 4) 8.3% 5dB (5, 5) 16.7% 5dB (2, 2) 16.7% 4dB (3, 3) 16.7% 4dB (4, 4) 33.3 % 2dB (5, 5) 33.3 % 4dB 6.0 5.0 (2, 2 ) (3, 3) (4, 4) NUM. of (DL, UL) TX. USERS FDM TDM (5, 5) FDM yields BETTER throughput performance than TDM System Level Simulation (1) Performance Metrics • Sector Throughput with satisfying MAP outage requirement • MAP Outage requirement: Distribution of user whose BLER is larger than 1% < 3% of total users Per User Power Control • PMAPIE[i] = SINRREQ– SINR(CQI)[i] + ∆MARGIN • SINRREQ: SINR value required to satisfy 1% BLER • SINR(CQI)[i]: i-th user SINR set by CQI feedback value • ∆MARGIN: Margin value to accomplish required MAP outage System Level Simulation (2) Major Assumptions • Subframe structure • 48 bits (including CRC) per assignment block • 1-D MAP region indication Assign. #1 Assign. Assign. #N Assign. #2 ... ... Assign. ... • Separate coding Assign. Assign. Assign. #1 #2 DATA Traffic DATA Traffic NRU,TOTAL • Only assignment block in MAP region 1/12 or 1/6 ⅹNRU,TOTAL • [IEEE C802.16m-08/062r1] 1 or 2 OFDMA symbols Assign. #N • Period: Semi-static MUX Orthogonal Resource Overhead FDM 8.3 or 16.7 % TDM 16.7 or 33.3 % Subframe (6 symbols) FDM Zero insertion TDM * 8.3%: Maximum DL4 UL4 assignment blocks 16.7%: Maximum DL8 UL8 assignment blocks 33.3%: Maximum DL16 UL16 assignment blocks System Level Simulation (3) Simulation Environments/Assumptions Index Deployment Scenario MCS for MAP HARQ Scheduler Value EMD baseline [IEEE 802.16m-07/037r2 ] QPSK, 1/2 Synchronous (No assignment message for retransmission) Proportional fairness # of Users per Sector 10 # of Scheduled Users 2, 3, 4, 5 per mini-frame (4, 6, 8, 10 for both DL and UL) MAP Error Effects Antenna Configuration Channel Model Channel Estimation Other Simulation Assumptions Resource loss for MAX retransmission SIMO 1x2 Mixed (Ped B-3kmph-60%, Veh A-30kmph-30%, Veh A-120kmph-10%) Real channel estimation (Equal impairment for both TDM and FDM) EMD baseline Power Saving (1) Micro-Sleep (within a sub-frame) • Symbol level power saving Power Saving Gain 3.5 Max( p, q ) xi zi Gi % 6 i 0 2 PSG = 2.04 % Power saving gain by Micro-sleep is NOT significant Required Time FFT 1 symbol MAP Region p symbols p=1 Pilot Region q symbols q=2 CH. Est. Delay 0.5 symbol Baseband Modem z0 MAP Decoding Minimum 1 symbol RF Parts Turn-off + Turn-on x0, x1, x2 Display Device Parts Portion of Power Consumption Time for turnoff + turn-on Power Saving Gain (%) 0.1 x0 1 symbols G1 50 z1 0.65 x1 1 symbols G2 30 z2 0.25 x2 - G3 - Power Saving (2) Default Subframe Concept • Sub-frame level power saving • Power saving gain can be much larger than Micro-sleep • One of sub-frame is pre-assigned to a MS as a default sub-frame, then the MS may go sleep mode during other sub-frame DL subframe UL subframe DL MAP UL MAP DL Subframe #2 ACK for UL DL Subframe #3 DL Subframe #4 UL Subframe #0 DL Data MSi Power Off DL Data UL Subframe #2 ACK for DL DL MAP UL MAP ACK for UL DL Subframe #3 UL Subframe #1 UL Data Power Off UL Subframe #1 ACK for DL Power Off RTG DL Subframe #1 TTG BS DL Subframe #0 UL Data Annex 2: Evaluation Results of 802.16m DL Control Structure Yi Hsuan, Ping Wang, Hujun Yin Intel Corporation Multiplexing Criteria II: Coverage Analysis 866m Cell (EMD Baseline Configuration) Test Scenarios QPSK ½ co QPSK ¼ co QPSK 1/8 c QPSK 1/12 verage verage overage coverage Outage FDM, Ped B Reuse 1, CDD 46.8% 67.2% 93% 98.4% 1.6% TDM, Ped B Reuse 1, CDD 44.5% 64.4% 89.3% 96.5% 3.5% FDM, Veh A Reuse 1, CDD 44.2% 62.8% 89.4% 96.2% 3.8% TDM, Veh A Reuse 1, CDD 43.1% 61.6% 85.4% 94.7% 5.3% Multiplexing Criteria II: Coverage Analysis 5000m Cell with Open Rural Macrocell Pathloss Model Test Scenarios QPSK ½ coverage QPSK ¼ coverage QPSK 1/8 coverage QPSK 1/12 coverage Outage FDM, Ped B Reuse 1, CDD 21.6% 43.9% 73.8% 87.2% 12.8% FFR, CDD 45.7% 80.2% 96.5% 100% 0 TDM, Ped B Reuse 1, CDD 19.2% 41.1% 66.3% 81.3% 18.7% FFR, CDD 42% 79.6% 96.5% 99.7% 0.3% FDM, Veh A Reuse 1, CDD 18.9% 38.9% 66.7% 79.9% 20.1% FFR, CDD 43.5% 77.6% 96.4% 99.6% 0.4% TDM, Veh A Reuse 1, CDD 18.4% 36.6% 60.5% 77% 23% FFR, CDD 44.8% 78.1% 94.6% 99.2% 0.8% Multiplexing Criteria II: Coverage Analysis 5000m Cell with Baseline Pathloss Model Test Scenarios QPSK ¼ co verage QPSK 1/8 c overage QPSK 1/12 coverage Outage FFR, CDD 24.7% No power boost 38.9% 54.2% 66.2% 33.8% FFR, CDD 3 dB boost 31.5% 48.7% 65.6% 78.9% 21.1% TDM, Ped B FFR, CDD 23.6% 37.8% 51.7% 63% 37% FDM, Veh A FFR, CDD 23.6% No power boost 35.9% 52% 62.3% 37.7% FFR, CDD 3 dB boost 30.4% 45.7% 64.3% 74.7% 25.3% FFR, CDD 23% 35.3% 48.4% 59.9% 40.1% FDM, Ped B TDM, Veh A QPSK ½ co verage Multiplexing Summary FDM has better link level performance and coverage than TDM because of channel estimation advantage for FDM. FFR improves coverage significantly in all cell sizes FDM allows power boosting for USCCH, which can improve the cell coverage in some cases. Annex 3: Performance Evaluation for IEEE 802.16m Downlink Control Structure Jun Yuan, Sophie Vrzic, Dongsheng Yu, Mo-Han Fong, Robert Novak, Hosein Nikopourdeilami, Kathiravetpillai Sivanesan, Sang-Youb Kim Nortel Networks Link Level Simulation Assumptions Table 1.1: Link Level Simulation Parameters Parameters Values Bandwidth 10 MHz FFT size 1024 Carrier Frequency 2.5 GHz Channel Model Pedestrian B 3 km/hr, ITU-Vehicular A 120 km/hr, DL Tx scheme 2 Tx antenna, STBC DL Rx scheme 2 Rx antenna Permutation and symbol structure 16e PUSC (baseline permutation in EMD) Channel Coding 16e CTC MCS QPSK ½ with repetition 0, 2, 4 and 6. Channel Estimation MMSE based on all pilots in 2 symbols for TDM and 6 symbols f or FDM TDM FDM Figure 1: Pilot Design Pilot for antenna 1 Pilot for antenna 2 Link Level Performance Results (1/2) 10 TDM QPSK, STTD 2x2, PB 3km/h 0 10 1/12 ideal 1/12 est 1/8 ideal 1/8 est 1/4 ideal 1/4 est 1/3 ideal 1/3 est 1/2 ideal 1/2 est 2/3 ideal 2/3 est -1 BLER 10 -2 -15 -10 -5 0 5 10 10 10 TDM QPSK, STTD 2x2, VA 120km/h 0 1/12 ideal 1/12 est 1/8 ideal 1/8 est 1/4 ideal 1/4 est 1/3 ideal 1/3 est 1/2 ideal 1/2 est 2/3 ideal 2/3 est -1 -2 -15 -10 -5 SNR 10 10 FDM QPSK, STTD 2x2, PB 3km/h 0 10 1/12 ideal 1/12 est 1/8 ideal 1/8 est 1/4 ideal 1/4 est 1/3 ideal 1/3 est 1/2 ideal 1/2 est 2/3 ideal 2/3 est -1 10 -2 -15 -10 -5 0 SNR 0 5 10 SNR BLER 10 BLER BLER 10 5 10 10 FDM QPSK, STTD 2x2, VA 120km/h 0 1/12 ideal 1/12 est 1/8 ideal 1/8 est 1/4 ideal 1/4 est 1/3 ideal 1/3 est 1/2 ideal 1/2 est 2/3 ideal 2/3 est -1 -2 -15 -10 -5 0 SNR 5 10 Link Level Performance Results (2/2) Table 2: MCS SNR at 1% BLER Code Rate TDM PB3km/h TDM VA120km/h FDM PB3km/h FDM VA120km/h QPSK ½ rep 6 -2.3188 (dB) -1.5222 (dB) -4.1482 (dB) -3.794 (dB) QPSK ½ rep 4 -1.7772 (dB) -0.9984 (dB) -2.8395 (dB) -2.8067 (dB) QPSK ½ rep 2 0.3323 (dB) 0.5476 (dB) -0.5509 (dB) -0.5688 (dB) QPSK ½ 3.5882 (dB) 3.4901 (dB) 3.0496 (dB) 2.9522 (dB) System Level Simulation Assumptions for Coverage Evaluation Table 1.2: System Level Simulation Parameters Parameters Values BS-to-BS distance 1.5km urban 5.0km open rural microcell NLOS Frequency reuse Reuse-1 Transmission power/sector 46 dBm BS height 32 m Tx antenna pattern 70o (-3dB) with 20 dB front-to-back ratio Tx antenna gain 17 dBi MS height 1.5 m Rx antenna pattern Omni directional Rx antenna gain 0 dBi MS Noise Figure 7 dB Penetration loss 10 dB Hardware losses (Cable, implementation, etc.) 2 dB Lognormal shadowing =0 dB, σSF =8 dB Shadowing correlation 100% inter-sector, 50% inter-BS Coverage Performance 1 0.9 0.8 0.7 CDF 0.6 1.5km urban: 95% SNR = -3.70dB 5.0km rural: 95% SNR = -5.88dB 0.5 0.4 0.3 0.2 0.1 0 -10 geo 1.5km Bs2Bs (sub)urban micro-cell geo 5.0km Bs2BS rural macro-cell -5 0 5 Geometry (dB) 10 15 20 Table 3: MCS for 95% cell-edge users TDM FDM w/o power boost FDM with 3dB power boost 1.5km PB3 Not Supportable QPSK ½ rep 6 QPSK ½ rep 4 1.5km VA120 Not Supportable QPSK ½ rep 6 QPSK ½ rep 4 5.0km PB3 Not Supportable Not Supportable QPSK ½ rep 6 5.0km VA120 Not Supportable Not Supportable QPSK ½ rep 6 System Level Simulation Assumptions for Capacity Evaluation Table 4: Simulation Assumptions Parameters Values Resource budget 30 slots TDM USCCH region 30 subchannels by 2 symbols FDM USCCH region 10 subchannels by 6 symbols Other hybrid schemes Total data subcarriers in the region should be the same as the above TDM or FDM scheme. Mininum resource unit Per MAP IE size Power budget 46 dBm for TDM 41.2 dBm for unboosted FDM (10 out of 30 subchannels are used so power budget should be 46-10log10(3)=41.2) 44.2 dBm for 3 dB boosted FDM Possible MCS QPSK ½, QPSK ½ repetition 2, QPSK ½ repetition 4, QPSK ½ repetition 6 Code scheme Separate encoding CID size 0 bit (masked by CRC) Start RB index 6 bits (or proposal specific value) Allocated RB 5 bits (or proposal specific value) Other L1/L2 information (data MCS etc.) x (5, 21,37) CRC 16 bits Total MAP IE sizes 32, 48, 64 bits (including CID, RB allocation and other L1/L2 information, and CRC) Power Sharing Yes for TDM and FDM BS-to-BS distance 1.5km Capacity Results Table 5: Number of Supportable Users PB 3km/h channel, 30 slots resources , at BLER = 1% realistic channel estimation 1.5km TDM 1.5km FDM (gain) 1.5km FDM Power Boost 3 dB (gain) 32 24 27 (13%) 41 (70%) 48 14 19 (35%) 28 (100%) 64 11 14 (27%) 20 (81%) sum 49 60 (22%) 89 (81%) MAP IE size Table 6: Number of Supportable Users VA 120km/h channel, 30 slots resources , at BLER = 1% realistic channel estimation 1.5km TDM 1.5km FDM (gain) 1.5km FDM Power Boost 3 dB (gain) 32 20 27 (35%) 41 (105%) 48 14 18 (28%) 28 (100%) 64 10 14 (40%) 20 (100%) sum 44 59 (34%) 89 (102%) MAP IE size Summary of Multiplex Schemes FDM outperforms TDM • From coverage perspective • Cell-edge users are supportable by FDM with power boost • Cell-edge users are not supportable by TDM • From capacity perspective • FDM (with power boost) achieves more than 20% (80%) capacity gain over TDM Reasons • FDM has ~2dB link level gain due to time-direction de-noising. • FDM has 3dB power boost gain.