1. Zhu dengkui,Jerry Chow E-mail: Zhu.dengkui@zte.com.cn
UL HARQ Feedback Channel Performance Comparisons of tile Format Options
Document Number: C80216m-09_0158
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Zhu dengkui,Jerry Chow
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content of IEEE m-08/003r6.”, “section UL HARQ Feedback Channel”
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2. Background
There exist several possible multiplexing unit format in the HARQ feedback channel:
2x6, 6x2, and 1x2 format
Different pilot patterns
Considerations
Detection error performance vs. channel conditions
Frequency selective, time selective
FDM legacy support

3. UL Tile Structure Alternatives3 3 3

4. Simulation Setup Parameters Value FFT Size 1024 Bandwidth 10 MHz
Carrier frequency
2.5 GHz
Number of transmit antennas 1
Number of receiver antennas 2
Resource block
18subcarriers x 6 OFDM symbols
Receiver Type
Coherent/Non-Coherent
Channel Model
Ped B – 3 km/h
Veh A – 120 km/h, 350 km /h
The correlation of channel
Antenna Interval: 4 λ, AS:5degree at BS
SNR
E/N0 per subcarrier 4

5. Performance Results – Veh A (120 km/h)5

6. Performance Results – Veh A (350 km/h)6

7. Observations & Conclusions
6x2 structure is equal to or better than 2x6 over all MS speeds
6x2 structure performs significantly better at very high MS speeds.
6x2 is not compatible with FDM with PUSC mode of UL legacy support.
For the format 1*2,although channels not changes notablely in the 2 symbols at high mobile speed, its deadly because of its short sequence, so the 1*2 shows a certain performance degrade than the 6*2 tile structure.
Need 2x6 only for FDM legacy support but 6x2 should supported for other UL configurations due to significant performance advantages
In order to capture the frequency diversity gain, DRU is used in HARQ feedback channel, where each tile of DRU is consist of three FMTs. 7

8. Proposal Text We suggest to change the following current description
PHY structure
We suggest to change the following current description
“The UL HARQ feedback channel is comprised of three distributed UL feedback mini-tiles (FMT), where the UL FMT is defined as 2 contiguous subcarriers by 6 OFDM symbols. A UL FMT of 6 contiguous subcarriers by 2 OFDM symbols is FFS. One LRU consists of 9 FMTs and can be shared by multiple HARQ feedback channels.” to
“The UL HARQ feedback channel is comprised of three distributed UL feedback
mini-tiles (FMT). One UL FMT is defined as 6 contiguous subcarriers by 2
OFDM symbols in the 16m-only frame or the mixed frame with UL TDM. And one UL FMT of 2 contiguous subcarriers by 6 OFDM symbols is used in the mixed frame with UL FDM. One LRU consists of 3 tiles where each tile consists of 3 FMTs, and can be shared by multiple HARQ feedback channels.