1. Proposed PHY Structure for the IEEE 802.16m HARQ Feedback Channel
Document Number: IEEE C80216m-09/0169
Date Submitted:
Source:
Changlong Xu, Qinghua, Li, Yuan, Zhu, {changlong.xu, hongmei.sun, intel.com
Hongmei Sun , Jong-kae (JK) Fwu, Hujun Yin, Sassan Ahmadi, Roshni Srinivasan
Intel Corporation
Venue:
IEEE Session #59, San Diego.
Re: m-08/052, Call for Comments on m SDD (802.16m-08/003r6), Section
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For discussion and adoption by TGm
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2. Outline Requirements on UL HARQ feedback
UL HARQ feedback channel design
Simulation performance

3. 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

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

5. 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

6. 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

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

8. 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.

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

10. Simulation Results

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

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

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

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

15. 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

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