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1 DL Power Control A-MAP Design (AWD-15.3.6.3.2.4) Document Number: IEEE C80216m-09/1363 Date Submitted: 2009-7-06 Source: Debdeep Chatterjee, Yi Hsuan,

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Presentation on theme: "1 DL Power Control A-MAP Design (AWD-15.3.6.3.2.4) Document Number: IEEE C80216m-09/1363 Date Submitted: 2009-7-06 Source: Debdeep Chatterjee, Yi Hsuan,"— Presentation transcript:

1 1 DL Power Control A-MAP Design (AWD-15.3.6.3.2.4) Document Number: IEEE C80216m-09/1363 Date Submitted: 2009-7-06 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 Venue: IEEE Session #62, San Francisco, CA. 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 DL Power Control A-MAP: Performance Requirements Each Power Control A-MAP (PC-A-MAP) IE is 2 bits long For 95% coverage for baseline cell size of 1.5km ISD: –Transmission with error rates (PER) not exceeding 10% at an SINR as low as -3.7dB For 95% coverage for larger cell size of 5km cell-radius: –Transmission with error rates (PER) not exceeding 10% at an SINR as low as -6dB

3 3 PC-A-MAP: Current AWD Text The repeated bit sequence shall be modulated as a QPSK symbol and scaled by an appropriate power boosting level that is determined by the management entity to satisfy the link performance. The above design requires considerable data tone power boosting to achieve the required performance for cell-edge users in interference-limited (IL) scenarios (cf. slide 8)

4 4 PC-A-MAP: Proposed Design Most significant bits (MSBs) of the i th and ( i+1) th PC-A-MAP IEs are mapped to a QPSK symbol Least significant bits (LSBs) of the i th and ( i+1) th PC-A-MAP IEs are mapped to a QPSK symbol Only one PC-A-MAP IE’s MSB and LSB may be mapped to 2 QPSK symbols to transmit to a user with poor channel quality –Equivalent to using BPSK symbols for the concerned user –No explicit signaling of the modulation scheme (between QPSK and BPSK) required –Helps avoid aggressive use of power boosting by efficient user scheduling Modulator(QPSK)SFBC i th PC- A-MAP IE PC-A-MAP symbols Repetition(x2) Modulator(QPSK)Repetition(x2) (i+1) th PC-A- MAP IE MSB MSB LSB LSB I-branch Q-branch I-branch Q-branch

5 5 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/Coding Two or one PC-A-MAP IE(s) mapped to two QPSK symbols, with 2 repetitions MIMO ReceiverMMSE 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 single PRU-based channel estimator Scenarios Interference-limited (IL): INR = 10dB, 2 interferers Interference-limited (IL): INR = 10dB, 3 interferers Interfering data symbols are always QPSK

6 6 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 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 the presence of interference

7 7 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

8 8 IL with 2 Interferers: Current AWD Design

9 9 IL with 2 Interferers: MMSE-CNC Rx, 2 PC-A-MAP IEs per 2 QPSK symbols

10 10 IL with 2 Interferers: MMSE-CNC Rx, 1 PC-A-MAP IE per 2 QPSK symbols

11 11 IL with 3 Interferers: MMSE-CNC Rx, 2 PC-A-MAP IEs per 2 QPSK symbols

12 12 IL with 3 Interferers: MMSE-CNC Rx, 1 PC-A-MAP IE per 2 QPSK symbols

13 13 Summary and Conclusion For IL scenarios, the MMSE-CNC Rx provides a gain of about 1dB (at 10% PER) over the MMSE receiver that assumes all noise + interference as white Using two repetitions is sufficient to satisfy the performance requirements Appropriate MCS adaptation (as above) may be used to avoid high amounts of data power boosting or de-boosting –Very high data power boosting causes 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) The data power boosting level can be limited to 4~5dB by appropriately scheduling and pairing PC-A-MAP IEs –The PC-A-MAP IE for a user with very poor channel condition may be mapped to a pair of QPSK symbols instead of two IEs to two QPSK symbols, thereby avoiding high data tone power boosting levels

14 14 Proposed AWD Text Change (1/2): Replace Figure 479 of 15.3.6.3.2.4 on page 190 with Figure 479 – Chain of PC-A-MAP IE to PC-A-MAP symbols Modulator(QPSK)SFBC i th PC- A-MAP IE PC-A-MAP symbols Repetition(x2) Modulator(QPSK)Repetition(x2) (i+1) th PC-A- MAP IE MSB MSB LSB LSB I-branch Q-branch I-branch Q-branch

15 15 Proposed AWD Text Change (2/2): Replace the lines 25 to 33 of 15.3.6.3.2.4 on page 190 with “The i th and ( i+1) th PC-A-MAP IEs shall be mapped to two QPSK symbols as depicted in Figure 479. Only the i th PC-A-MAP may also be mapped to two QPSK symbols for transmitting to the corresponding MS with poor channel quality. Power scaling by ( 0 ≤ i < N PC-A-MAP-IE ) shall be applied to the i th PC-A- MAP-IE where N PC-A-MAP-IE is the number of PC-A-MAP-IEs and is the value determined by the management entity to satisfy the link performance. The QPSK symbols are repeated N rep,PC-A-MAP-IE times, where N rep,PC-A-MAP- IE equals two.”


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