1. Performance comparison of Constellation Rearrangement and Bit Rearrangement IEEE 802.16 Presentation Submission Template (Rev. 9) Document Number: IEEE C802.16m-09/0189 Date Submitted: 2009-01-05 Source: Hyungho Park, Sukwoo Lee Voice: +82-31-450-1934 LG Electronics, Inc.E-mail:hyunghopark@lge.com, sugoo@lge.comhyunghopark@lge.comsugoo@lge.com Hyungjoon Jeon, Jungnam Yun POSDATA Co., Ltd.E-mail:jnyun@posdata-usa.com * http://standards.ieee.org/faqs/affiliationFAQ.html Re : IEEE 802.16m-08/052, “Call for Comments on Project 802.16m System Description Document (SDD)”, Supporting contribution on the comment of SDD section 11.13.2.2 Purpose: To be discussed and adopted by TGm for 802.16m SDD 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. HARQ scheme for IEEE 16m 16m HARQ schemes with consideration of unequal bit error probability –Constellation Rearrangement (CoRe) In case of high modulation order, modulated symbols consist of component bits with different bit reliability level. Such a bit reliability difference results in performance degradation in channel decoding. Constellation Rearrangement is well known scheme which can achieve significant performance gain by averaging out unequal bit reliabilities. The performance of CoRe is guaranteed as an additional HARQ gain regardless of MS’s mobility, frequency channel selectivity and resource allocation type.

3. HARQ scheme for IEEE 16m –Bit Rearrangement (BitRe) using different bit reliability of systematic and parity bits There exists bit reliability difference between systematic and parity bits. By mapping systematic bits to MSB (Most Significant Bit) within signal constellation, the reliability of systematic bits can be improved. However, bit reliability difference between coded bits still remains when chase LLR combining. Unequal bit reliability caused by QAM mapping with high modulation order is more important than the different bit reliability of systematic and parity bits.

4. HARQ scheme for IEEE 16m –Bit Rearrangement (BitRe) to exploit frequency diversity In order to exploit an additional frequency diversity gain, BitRe was proposed to map MSB or LSB to different carrier which is apart from the previous assigned carrier location. In case of distributed resource allocation, since frequency diversity gain is already achieved by distributed resource allocation, it is very unlikely to get an additional gain by BitRe. In case of localized resource allocation, it is not intended to get frequency selective diversity gain, and it is hardly achieved due to the low fluctuation of CINR level. Under the fast fading channel and distributed resource allocation, the BitRe scheme has almost the same performance gain as a conventional HARQ scheme.

5. Performance comparison Simulation Parameters ParametersAssumption Bandwidth10 MHz Number of subcarrier1024 Frame length5ms Channel estimationPerfect Channel codeCTC ½ Modulation16 QAM MIMO configurationTx: 1, Rx:1 or 2 Resource allocationPUSC Channel modelAWGN, PedB,VehA MS mobility30km/h, 120km/h Receiver typeLinear MMSE Maximum number of retransmission1 Retransmission latency10ms

6. SIMO, PedB 30km/h Performance Comparison

7. SIMO, VehA 120km/h Performance Comparison

8. SISO, VehA 3km/h by LGE Performance comparison by ITRI (SISO, VehA 0km/h, C802.16m-08/1144r1) [1] in the legend means ZTE BitRe scheme LGE result shows almost no gain with BitRe in term of FER performance though it shows a little bit of gain in terms of BER performance

9. Text Proposal for 802.16m SDD ------------------------------------------- Start of the Text ---------------------------------------------- -------------------------------------------- End of the Text ---------------------------------------------------- 11. 13. 2.2. Constellation re-arrangement Bit re-arrangement Bit re-arrangement (BitRe) is supported in 802.16m. Bit re-arrangement includes a bit-level interleaver and an inverter. For each transmitted burst, the BitRe-version is selected by the transmission number of this burst. The specific bit-level interleaver and inverter mechanism is FFS. Constellation re-arrangement (Co-Re) is supported in 802.16m. For each transmitted bit the CoRe-version is selected by the number of transmission of this bit. The specific selection mechanism is FFS.