1. 8Tx Pilot Pattern Performance for IEEE 802.16m IEEE 802.16 Presentation Submission Template (Rev. 9) Document Number: IEEE C802.16m-09/0544 Date Submitted: 2009-03-02 Source: Jerry Pi, Taeyoung Kim, Hai Wangzpi@sta.samsung.comzpi@sta.samsung.com Samsung Electronics Venue: Re : 802.16m AWD Base Contribution: IEEE C802.16m-08/0544 Purpose: To be discussed in TGm in support of the IEEE 802.16m amendment text proposed in C80216m-09_0515 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-08/003r6, section 11.8.1.1, page 98, line 12 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 Pilot tones are placed in the middle of a subframe – resulting in more extrapolation instead of interpoloation – Making it difficult to adapt the pilot pattern to 5-OFDM symbol subframe 5

6. Simulation Assumptions 8Tx Pilot Pattern – Pilot Pattern 1 vs. Pilot Pattern 2 vs. Pilot Pattern 3 – The same number of information bits are transmitted using different pilot patterns – The difference in pilot density are taken into account by rate matching Pilot Pattern 2 results in less number of resource elements available for data and thus higher code rate Pilot Pattern 1 & 3 have the same number of resource elements for data and thus the same code rate – 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 – 3 contiguous PRUs – 2D MMSE channel estimator per PRU Metric: – BLER – MSE 6

7. 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 more sensitive to high speed channel conditions Recommendation – Adopt the proposed pilot pattern as in the next page into 802.16m AWD – The detailed text proposal is provided in C80216m- 09_0515 7

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9. SIMULATION RESULTS – 8TX PILOT PATTERNS (RANK 8) 9

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36. Observation 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 more sensitive to high speed channel conditions (esp. for higher order modulations) 36