1. 1 Pilot Pattern for 8-Stream Transmission Document Number: IEEE C80216m-09/1138 Date Submitted: 2009-05-01 Source: Debdeep Chatterjee, Jong-kae (JK) Fwu, Huaning Niu, Hujun Yin Email: {debdeep.chatterjee@intel.com, jong-kae.fwu@intel.com, huaning.niu@intel.com, hujun.yin@intel.com}{debdeep.chatterjee@intel.com huaning.niu@intel.comhujun.yin@intel.com Intel Corporation Venue: IEEE Session #61, Cairo, Egypt. Re: “Call for Contributions on Project 802.16m Amendment Working Document (AWD) Content” Base Contribution: N/A Purpose: For TGm discussion and adoption of 802.16m SDD or AWD text. Notice: This document does not represent the agreed views of the IEEE 802.16 Working Group or any of its subgroups. It represents only the views of the participants listed in the “Source(s)” field above. It is offered as a basis for discussion. It is not binding on the contributor(s), who reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.16. Patent Policy: The contributor is familiar with the IEEE-SA Patent Policy and Procedures: and.http://standards.ieee.org/guides/bylaws/sect6-7.html#6http://standards.ieee.org/guides/opman/sect6.html#6.3 Further information is located at and.http://standards.ieee.org/board/pat/pat-material.htmlhttp://standards.ieee.org/board/pat

2. 2 Overview 8-stream transmission is suitable for high SNR scenarios and for the purpose of providing very high data rates –8-stream spatial multiplexing (SM) is a natural choice for this –Rank-8 precoding not very realistic as 16 or more antennas at the BS would be a very extreme consideration For subband-based resource allocation and 8-stream SM mode multiple-PRU based channel estimation can be supported In this work, we compare 8-stream pilot patterns proposed by Samsung and ITRI for different channel estimation window sizes and scenarios

3. 3 Calculation of Spectral Efficiency Spectral efficiency (SE) –Method 1: –Method 2: System bandwidth (= 10 MHz in this work) Length of subframe (in seconds) (= 0.625 ms in this work) # of streams (= 8 for the present problem) Code rate (16e CTC code rate) Modulation order (QPSK = 2, 16QAM = 4, 64QAM = 6) # of OFDM symbols in a subframe (= 6 in this work) # of subcarriers in a PRU (= 18 in this work) # of pilot tones per PRU (=16 for 2 pilots/stream; =24 for 3pilots/stream) # of PRUs in a subframe (= 48 in this work)

4. 4 Simulation Parameters OFDM parameters10 MHz (1024 subcarriers) Number of OFDM symbols per subframe6 Data to subcarrier mappingData payload adjusted according to MCS and pilot pattern to map to 3 CRUs PermutationNone (CRU) Number of total RU in one subframe48 Number of Antennas8 transmitter antennas, 8 receiver antennas [8Tx,8Rx] Transmission mode8x8 SM Channel coding16e CTC with 8 Turbo decoding iterations; Uncoded block size = 480 bits Modulation/CodingQPSK ½, QPSK ¾, 16QAM ½, 16QAM ¾, 64QAM 2/3, and 64QAM 5/6 Channel model Extension-ITU-Ped B, 3kmph Extension-ITU-Veh A, 30kmph & 120kmph Channel estimation 2-D MMSE channel estimator with 1-PRU, 2-PRU and 3-PRU CE Delay Spread perfectly known Actual PDP unknown, assumed to be flat at receiver Pilot boosting Each antenna boosts its pilot tone by 5dB MIMO detector LMMSE Scenarios Noise limited Spectral Efficiency Calculation Using ITRI’s proposed method (Method 2 in previous page)

5. 5 Pilot Patterns Evaluated (1 of 4) ITRI (Set 1): Pilot density = 2 pilots per stream

6. 6 Pilot Patterns Evaluated (2 of 4) Samsung: Pilot density = 3 pilots per stream

7. 7 Pilot Patterns Evaluated (3 of 4) ITRI (Set 3): Pilot density = 2 pilots per stream

8. 8 Pilot Patterns Evaluated (4 of 4) ITRI (Set ‘a’): Pilot density = 2 pilots per stream

9. 9 Spectral Efficiency: Ped-B, 3kmph, 3-PRU CE ITRI’s pilot pattern (Set 1) outperforms Samsung’s pilot pattern in almost all SNR values

10. 10 Spectral Efficiency: Veh-A, 30kmph, 3-PRU CE ITRI’s pilot pattern (Set 1) outperforms Samsung’s pilot pattern in almost all SNR values

11. 11 Spectral Efficiency: Veh-A, 120kmph, 3-PRU CE ITRI’s pilot pattern (Set 1) outperforms Samsung’s pilot pattern

12. 12 Spectral Efficiency: Ped-B, 3kmph, 2-PRU CE ITRI’s pilot patterns (Sets 3, ‘a’) outperform Samsung’s pilot pattern for SNR <= 43dB

13. 13 Spectral Efficiency: Veh-A, 120kmph, 2-PRU CE ITRI’s pilot pattern (Set 3) outperforms Samsung’s pilot pattern

14. 14 Summary For 3-PRU channel estimation –ITRI’s pilot pattern (Set 1) outperforms Samsung’s pilot pattern for both Ped-B (3kmph) as well as Veh-A (120kmph) channel models For 2-PRU channel estimation –ITRI’s patterns (Sets 3 and ‘a’) outperform Samsung’s pattern until an SNR of about 43dB, and the latter pattern outperforms ITRI’s patterns as the SNR increases further –ITRI’s Set 1 pattern performs a little worse compared to Sets 3 and ‘a’ –ITRI’s Set 3 appears to perform the best amongst sets 1, 3, and ‘a’ –ITRI’s Set 3 outperforms Samsung’s pilot pattern for Veh-A 120kmph channel model

15. 15 BACKUP

16. 16 Spectral Efficiency: Ped-B, 3kmph, 1-PRU CE ITRI’s pilot pattern (Set 1) slightly outperforms Samsung’s pilot pattern for SNR <= 33dB Samsung’s pilot pattern outperforms ITRI’s Set 1 pattern for SNR higher than 33dB