1. E-MBS Feedback Channel Design (E-MBS) Document Number: IEEE C802.16m-09/1877 Date Submitted: 2009-08-28 Source: Chih-Yuan Lin (chihyuan.lin@mediatek.com), Pei-Kai Liao (pk.liao@mediatek.com), Yih-Shen Chen (yihshen.chen@mediatek.com),chihyuan.lin@mediatek.compk.liao@mediatek.comyihshen.chen@mediatek.com Yu-Hao Chang (yuhao.chang@mediatek.com), and Paul Cheng (paul.cheng@mediatek.com)yuhao.chang@mediatek.compaul.cheng@mediatek.com MediaTek Inc. Venue: IEEE Session #63, Jeju, Korea Re: P802.16m/D1 E-MBS Base Contribution: N/A Purpose: Propose to be discussed and adopted by TGm for the use in Project 802.16m 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

2. Objectives ▪ Details of E-MBS feedback channel are missing –Aim to propose detailed PHY structure and corresponding sequences ▪ Design criteria –Common feedback channel All AMs can announce their NACKs in this feedback channel –FDM and CDM hybrid PHY structure Example AMS randomly chooses a frequency partition, and also randomly chooses a code to announce its NACK

3. E-MBS Feedback PHY (1/2) ▪ Possible candidates for E-MBS mini-tile (EMT) –1x2 / 2x1 / 2x2 / 2x6 / 6x2 / 6x6 / 18x6 ▪ Frequency-first manner to allocate CDM code

4. E-MBS Feedback PHY (2/2) ▪ Comparison between different tile sizes –Time-domain span should not be too large Easy to maintain code orthogonality under high-mobility case –Feedback resource unit is easy to be put into existing feedback mini-tile or DRU tile No need to create new tile size and permutation rule for E-MBS feedback channel As a result, 2x1, 2x2 and 6x2 mini-tile sizes are preferred – 2x2 case is the same as the HARQ mini-tile and so is a good choice since corresponding length-4 orthogonal codes are already determined

5. Simulation Parameters (1/1) ▪ 1x2 SIMO –MSs have one TX antenna and BS has two RX antennas ▪ Code type: orthogonal code –For 2x2, 6x2, and 2x6 unit sizes, hadamard code is used –For 6x6 and 18x6 unit sizes, DFT code is used since there are no length-36 and length-108 hadamard codes ▪ Receiver type: non-coherent detection ▪ Each MS has equal TX power ▪ Feedback resource : one LRU (18x6) –108 feedback opportunities in total ▪ Channel model: VA 120 ▪ Performance metric: estimation error of number of users

6. Simulation Results (1/2) ▪ VA 120 and number of users = 80 (collision free) SNR (dB)-4-20246810 Error (HDM)2.04161.68331.37501.35001.46661.02501.00831.1750 2x2 tile size SNR (dB)-4-20246810 Error (HDM)8.07008.38007.85007.32007.19006.83007.00006.7300 SNR (dB)-4-20246810 Error (HDM)1.59161.27501.14161.07500.95831.16660.82500.8916 SNR (dB)-4-20246810 Error (DFT)4.92504.69164.47504.41664.35003.82504.26664.2083 SNR (dB)-4-20246810 Error (DFT)6.80836.31666.32505.92506.45836.22506.15005.9000 2x6 tile size 6x2 tile size 6x6 tile size 18x6 tile size

7. Simulation Results (2/2) ▪ VA 120 and number of users = 80 (10% of them collide with others) –8 AMSs randomly choose 8 feedback channels among that of other 72 MSs SNR (dB)-4-20246810 Error (HDM)6.30006.55006.66666.25005.50004.68334.13333.4666 2x2 tile size SNR (dB)-4-20246810 Error (HDM)20.033319.766620.116619.416618.250017.966616.266615.0333 SNR (dB)-4-20246810 Error (HDM)4.01663.96663.43333.91663.20003.13333.01662.7333 SNR (dB)-4-20246810 Error (DFT)15.925014. 55014.475014. 266614. 416613.825014. 033314.2083 SNR (dB)-4-20246810 Error (DFT)16.200016.066616.683315.933315.316615.600015.583315.5166 2x6 tile size 6x2 tile size 6x6 tile size 18x6 tile size

8. Conclusion (1/1) ▪ The cases with 2x2 and 6x2 tile sizes perform relatively good –Experience less channel time variation effect ▪ EMT of size 2x2 is preferred –Same PHY structure as HARQ feedback channel and thus no additional complexity One E-MBS feedback is composed of 3 FMTs to provide 36 feedback opportunities –Better to be used in legacy zone, whose tile size is 4x6 time Freq.

9. Text Proposal

10. Appendix (1/2) ▪ Determination of threshold of non-coherent detection –Received signal model in a mini resource block N : number of users : i th user’s code with N subcarreir denoted as number of tones in a CDM resource unit : i th user’s channel frequency response in a CDM resource unit : noise vector –Non-coherent detection Detect k th user

11. Appendix (2/2) –Detection criteria : output power of non-coherent detector is larger than interference-plus-noise power, i.e., Expectation can be expanded as – can be obtained by predefining MS mobility and channel delay spread ▪ In simulations, mobility is set to be 120 km/hr and channel delay spread is set to be 5 us for all scenario ▪N is set to be (maximal allowable number of users)/2