1. 8Tx Dedicated Pilot Pattern Simulation Results IEEE 802.16 Presentation Submission Template (Rev. 9) Document Number: IEEE C802.16m-09/0805 Date Submitted: 2009-04-27 Source: Jay Tsai, Jerry Pi, Taeyoung Kim, Hai Wangjtsai@sta.samsung.comjtsai@sta.samsung.com Samsung Electronics Venue: Re : TGm Call for Contributions and Comments 802.16m-08/003r8 for Session 61 Base Contribution: IEEE C802.16m-08/0007 Purpose: To discuss and adopt the proposed text in the revision of the 802.16m SDD or AWD 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 1

2. Background Downlink 8Tx MIMO is adopted in SDD – IEEE 802.16m-08/003r8 8Tx pilot pattern is yet to be defined This contribution proposes the 8Tx pilot pattern for IEEE 802.16m downlink 2

3. 8Tx Pilot Pattern (1) 8 pilot streams – Overhead: 3/108 = 2.78% each – Total overhead 24/108 = 22.22% Mirrored pilot patterns – Pilot patterns for P 1, P 2, P 3, P 4 mirror in time and frequency – Pilot patterns for P 5, P 6, P 7, P 8 mirror in time and frequency – Low complexity implementation of channel estimation Easy to adapt for 5-symbol subframes (by removing the 3 rd or 4 th symbol in the pilot pattern for 6-symbol subframes) 3

4. 8Tx Pilot Pattern (2) 8 pilot streams – Overhead: 4/108 = 3.7% each – Total overhead 32/108 = 29.63% Mirrored pilot patterns – Reuse the 4Tx pilot patterns for P 1, P 2, P 3, P 4 (See next page for updated 4Tx pilot pattern) – Pilot patterns for P 1, P 2, P 3, P 4 mirror in time and frequency – Pilot patterns for P 5, P 6, P 7, P 8 mirror in time and frequency – Low complexity implementation of channel estimation – Easy to adapt for 5-symbol subframes (by removing the 3 rd or 4 th symbol in the pilot pattern for 6-symbol subframes) 4

5. 8Tx Pilot Pattern (3) Proposed by Fujitsu – C80216m-09/0215, 0277 5

6. 8Tx Pilot Pattern (4) Proposed by ITRI – C80216m- 09_0570 2 tones/pilot/PRU 6

7. Simulation Assumptions 8Tx Pilot Pattern – Pilot Pattern 1, 2, 3, 4 – Rank-8 precoder cycling – Channel models: Ped A 3kmph, Ped B 3kmph, Veh A 30kmph, Veh A 120kmph, Veh A 350kmph – MCS QPSK 1/2, QPSK 1/3, 16QAM 1/2, 16QAM 1/3, 64QAM 1/2, 64QAM 1/3 Note the code rate is nominal assuming no pilot. The actual code rate is higher because of resource puncturing due to pilot streams – 3 contiguous PRUs – 2D MMSE channel estimator per PRU Metric: – BLER – MSE 7

8. Summary 8Tx Pilot Patterns – Pilot Pattern 1 & 3 (3 pilot tones per stream) outperforms Pilot Pattern 2 (4 pilot tones per stream) in Rank 8 transmissions – Pilot Pattern 3 is sensitive to high speed channel conditions than Pilot Pattern 1 – Pilot pattern 4 is sensitive to both time and frequency selectivity Out of the 30 test cases, pilot Pattern 4 outperforms Pilot Pattern 1 in 6 cases when both frequency and time selectivity are limited but underperform Pilot Pattern 1 in 15 cases (performance are comparable in other cases) – Recommend to use Pilot Pattern 1 for overall performance and robustness consideration Recommended SDD text change – Section 11.5.3, page 80, line 7 Insert the figure as in page 8 of C80216m-09_xxxx – Section 11.5.3, page 80, line 8 Add “The pilot patterns for 8 pilot streams are shown in the figure above. The pilot pattern for 6- symbol subframe is shown in subfigure (a); the pilot pattern for 5-symbol subframe is shown in subfigure (b); the pilot pattern for 7-symbol subframe is shown in subfigure (c).” 8

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10. SIMULATION RESULTS – 8TX PILOT PATTERNS (RANK 8) 10

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