Proposed PHY Structure for the IEEE 802.16m HARQ Feedback Channel Document Number: IEEE C80216m-09/0169 Date Submitted: 2009-01-05 Source: Changlong Xu, Qinghua, Li, Yuan, Zhu, Email: {changlong.xu, hongmei.sun, jong-kae.fwu} @ intel.com Hongmei Sun , Jong-kae (JK) Fwu, Hujun Yin, Sassan Ahmadi, Roshni Srinivasan Intel Corporation Venue: IEEE Session #59, San Diego. Re: 802.16m-08/052, Call for Comments on 802.16m SDD (802.16m-08/003r6), Section 11.9.2.2 Base Contribution: N/A Purpose: For discussion and adoption by TGm 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: <http://standards.ieee.org/guides/bylaws/sect6-7.html#6> and <http://standards.ieee.org/guides/opman/sect6.html#6.3>. Further information is located at <http://standards.ieee.org/board/pat/pat-material.html> and <http://standards.ieee.org/board/pat >.

Outline Requirements on UL HARQ feedback UL HARQ feedback channel design Simulation performance

Requirements for the UL HARQ Channel Evaluation Requirement Document: Target PER of 1% for ACK to NACK error. Target PER of 0.1% for NACK to ACK error

UL HARQ feedback channel & PHY Structure UL HARQ feedback channels are carried in UL Control DRU

PHY structure for UL HARQ feedback channel Each logical UL HARQ feedback channel occupies 3 FMT FMT (Feedback Mini-Tile, Nsub x Nsym): 2x6 Each LRU (18x6) can accommodate 3 logical UL HARQ feedback channels

Option 1: TDM/CDM Design Each 2×6 tile size includes 3 tile size of 2×2 Walsh codes with length of 4 with BPSK modulation are used for ACK/NACK of two users with CDM Transmit power per tone is 4.7dB boosting Non-coherent detection

Option 2: TDM/FDM Design Two structures have similar performance For each user ACK 1 1 NACK 1 -1 Transmit power per tone is 7.7dB boosting Non-coherent detection Structure 1 Structure 2

Payload for UL HARQ feedback channel One logical UL HARQ feedback channel supports up to 6 1-bit ACK/NACKs (6 users) simultaneously. One logical UL HARQ feedback channel supports up to 3 2-bit ACK/NACKs (3 users) simultaneously for Option 1 only.

Parameters for simulation Carrier frequency 2.5GHz Bandwidth 10MHz FFTSize 1024 Antenna configuration 1 Tx, 2 Re Channel mode PedB3, VA 60, VA120, VA350 Number of user 6 users Decoding algorithm non-coherent detection

Simulation Results

Performance for UL HARQ feedback channel TDM/CDM (Option 1) Ratio (ACK-> NACK/ NACK-> ACK) threshold set to 0.7

Performance for UL HARQ feedback channel TDM/CDM (Option 1)

Performance for UL HARQ feedback channel TDM/FDM (Option 2 )

Performance for UL HARQ feedback channel TDM/FDM (Option 2)

Summary for simulation results Channel Type Working point of SNR PB3 -4.0dB to -3dB 2x6 tile is suggested for unified ACK/NACK design to support both greenfield and legacy scenarios VA60 VA120 VA350

Recommendations Adopt the TDM/FDM tile structure 2 for the 802.16m HARQ Feedback channel