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1 HARQ Feedback AMAP Design Document Number: IEEE C80216m-09/1029 Date Submitted: 2009-4-27 Source: Debdeep Chatterjee, Yi Hsuan, Hujun Yin

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Presentation on theme: "1 HARQ Feedback AMAP Design Document Number: IEEE C80216m-09/1029 Date Submitted: 2009-4-27 Source: Debdeep Chatterjee, Yi Hsuan, Hujun Yin"— Presentation transcript:

1 1 HARQ Feedback AMAP Design Document Number: IEEE C80216m-09/1029 Date Submitted: 2009-4-27 Source: Debdeep Chatterjee, Yi Hsuan, Hujun Yin Email: {debdeep.chatterjee@intel.com, yi.hsuan@intel.com, hujun.yin@intel.com}{debdeep.chatterjee@intel.com yi.hsuan@intel.comhujun.yin@intel.com Intel Corporation Hyunkyu Yu, Jaeweon Cho, Heewon Kang, Hokyu Choi Email: {hk.yu@samsung.com }{hk.yu@samsung.com Samsung Hyungho Park, Jinsoo Choi, Bin-chul Ihm, Jin Sam Kwak Email: {hyunghopark, emptylie, bcihm, samji}@lge.com LGE Venue: IEEE Session #61, Cairo, Egypt. Re: AWD comments / Area: Chapter 15.3.6 (DL-CTRL), “Comments on AWD 15.3.6 DL-CTRL” Base Contribution: N/A Purpose: For TGm discussion and adoption of 802.16m AWD text. 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 2 HARQ Feedback AMAP: Performance Requirements Maximum error rates for HARQ Feedback AMAP: –Pr [NAK  ACK] = 0.1% –Pr [ACK  NAK] = 1% For 95% coverage for baseline cell size of 1.5km ISD: –Transmission with error rates not exceeding the above at an SINR as low as -3.7dB For 95% coverage for larger cell size of 5km cell-radius: –Transmission with error rates not exceeding the above at an SINR as low as -6dB

3 3 HARQ Feedback AMAP: Proposed Design Each HF-A-MAP IE carries 1 bit information Depending on the channel conditions, the modulation can be QPSK or BPSK –If QPSK is used, then 2 ACK IEs are mapped to a point in the signal constellation –If BPSK is used, then each ACK IE is mapped to a point in the signal constellation Frequency resource usage: 4 or 8 tones per user (i.e. HF-A-MAP IE) corresponding to QPSK or BPSK modulation QPSK/BPSKSFBC HF-A-MAP IE(s) [2 bits if QPSK;1 bit if BPSK] HF-A- MAP symbols Repetition(x8) QPSK/BPSKRepetition(x8) HF-A-MAP IE(s) [2 bits if QPSK;1 bit if BPSK]

4 4 Simulation Parameters Total available bandwidth10 MHz (1024 subcarriers) Carrier Frequency2.5GHz Number of OFDM symbols per subframe6 Number of total RU in one subframe48 Number of Antennas2 transmitter antennas, 2 receiver antennas [2Tx,2Rx] MIMO mode2x2 SFBC Tone selectionFully distributed (uniformly) over the entire band in units of tone-pairs (SFBC) Modulation/CodingQPSK or BPSK, with 8 repetitions in the frequency domain MIMO Receiver MMSE with White Noise Assumption (MMSE-WNA) with perfect SINR at Rx MMSE with Colored Noise Consideration (MMSE-CNC) Traffic modeleITU-VehA 120 km/h Pilot patterns 2-stream pilot pattern as in SDD Pilot boosting Each Tx. antenna boosts its pilot tone by 5dB Channel estimation 2-D MMSE PRU-based channel estimator Scenarios Noise-limited (NL): SIR = Inf Interference-limited (IL): INR = 10dB, 2 interferers, interfering data symbols are always QPSK Probability of error (BER) operating points 0.1% probability for both ACK  NACK and NACK  ACK errors.

5 5 The MMSE-CNC Receiver (1/2) MMSE receiver that estimates the noise + interference power from the pilot tones and performs MMSE detection/equalization with colored noise consideration Unlike the MMSE-WNA Rx, perfect knowledge of SINR at the receiver is not assumed. The receiver estimates the noise power from the pilots –Causes some degradation in the noise-limited performance, but this is more realistic The MMSE equalization is performed using the estimated noise covariance matrix (that may be colored in the presence of interference), instead of the white noise assumption (for which the noise covariance matrix is diagonal) –Improves the performance in interference-limited scenarios

6 6 The MMSE-CNC Receiver (2/2) Received symbol: Noise covariance estimated from the pilots averaged over a particular PRU (or over 3 PRUs when wideband channel estimation is supported): For a particular data tone, the estimated noise covariance matrix is Proceed with the standard MMSE detection/equalization with as the noise covariance matrix for data tone

7 7 Noise-Limited (NL): QPSK Modulation, MMSE-WNA Rx (Perfect Noise Covariance from SNR at Rx)

8 8 NL: QPSK Modulation, MMSE-CNC Rx

9 9 NL: BPSK Modulation, MMSE-WNA Rx (Perfect Noise Covariance from SNR at Rx)

10 10 NL: BPSK Modulation, MMSE-CNC Rx

11 11 Interference-Limited (IL): QPSK Modulation, MMSE-WNA Rx, Interfering data = QPSK symbols

12 12 IL: QPSK Modulation, MMSE-CNC Rx, Interfering data = QPSK symbols

13 13 IL: BPSK Modulation, MMSE-WNA Rx, Interfering data = QPSK symbols

14 14 IL: BPSK Modulation, MMSE-CNC Rx, Interfering data = QPSK symbols

15 15 Summary and Conclusion The MMSE-CNC Rx results in approximately 0.75~1dB degradation (at 0.1% BER) when compared to the MMSE-WNA Rx with perfect SNR at the receiver for NL scenarios The MMSE-CNC Rx provides gains of about 2.4~2.8dB (at 0.1% BER) over the MMSE-WNA Rx for IL scenarios The data power boosting level can be limited to 4~5dB by appropriately choosing the MCS (QPSK or BPSK) according to user channel conditions. –ACK IEs for users with very poor channel conditions may be transmitted using BPSK modulation instead of increased data power boosting Appropriate MCS adaptation (as above) potentially avoid high amounts of data power boosting or de-boosting –Very high data power boosting may cause high co-channel interference –Severe data power de-boosting, on the other hand, may cause the de-boosted data tones to be very sensitive to effects of inter-channel interference (ICI) Even further performance gains may be realized by exploiting the fact that the ACK  NAK and NAK  ACK error probability requirements are unequal –A suitably chosen non-zero threshold may be used at the threshold detection block in the receiver (the hard decision step) at the receiver

16 16 Proposed AWD Text Change: Replace Figure 428 on page 53 with the following figure and add the following text after line 58. “Each HF-A-MAP IE carries 1 bit information. Depending on the channel conditions, the modulation can be QPSK or BPSK. If QPSK is used, 2 HF-A-MAP IEs are mapped to a point in the signal constellation. If BPSK is used, each HF-A-MAP IE is mapped to a point in the signal constellation. The repetition number is FFS.” QPSK/BPSKSFBC HF-A-MAP IE(s) [2 bits if QPSK;1 bit if BPSK] HF-A-MAP symbols Repetition QPSK/BPSKRepetition HF-A-MAP IE(s) [2 bits if QPSK;1 bit if BPSK]


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