Performance Evaluation of PMI coordination based multicell MIMO

Performance Evaluation of PMI coordination based multi-cell MIMO for IEEE 802. 16 m IEEE 802. 16 Presentation Submission Template (Rev. 9) Document Number: S 80216 m-09_1625 Date Submitted: 2009 -07 -12 Source: Sangwoo Lee, David Mazzarese, Shuangfeng Han, Heewon Kang, Hokyu Choi Samsung Electronics sangwoo 07. lee@. samsung. com d. mazzarese@samsung. com Venue: Re : 802. 16 m IM DG, reply to comment 376 Base Contribution: C 80216 m-09_1625 Purpose: To be discussed and adopted by IM DG for incorporation in the 802. 16 m Amendment Working Document. 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/sect 6 -7. html#6> and <http: //standards. ieee. org/guides/opman/sect 6. html#6. 3>. Further information is located at <http: //standards. ieee. org/board/pat-material. html> and <http: //standards. ieee. org/board/pat >. 1

Introduction • The base contribution C 80216 m-09_1625 proposes details for the IMDG text proposed in C 80216 m-09_1540 r 1 for PMI coordination with single BS processing • PMI coordination performance evaluation is provided in this set of slides. It shows that the feedback of a single PMI is not sufficient to reduce the interference to levels that provide a significant gain. • It also shows that the feedback is beneficial when provided per subband, so the feedback of subband index is also a good feature to have. 2

Simulation Parameters Cellular layout inter-site distance Fading channel Assumption 7 cell, 3 sectors per cell 1500 m ITU-Ped. B MS speed 3 km/h carrier freq 2. 5 GHz bandwidth 10 MHz Number of MS per sector 8 CQI delay 5 PMI/CQI feedback period 1 subframe Feedback delay 1 subframe duration number of dominant interference seen by each MS PMI coordination update period Backbone delay for PMI coordination Antenna configuration BS ant distance receiver type rank 0. 625 ms 8 32 subframes 0 subframe 4 x 2 0. 5 l or 4 l MMSE 1 channelization band AMC mode Codebook type 16 m 4 bit CB

Simulation Assumptions • Upper Bound: – Each ABS schedules its MSs while successfully requesting each neighboring ( = interfering) cell to adopt recommendation PMIs. – Each neighboring cell, when receiving multiple recommendation PMIs which may cause conflicts, is assumed to resolve the conflicts in an ideal manner.

Simulation Results < Table 1 > UB vs. a practical evaluation Case no BS antenna spacing (l) PMI coordination scheme Average sector goodput 5% edge user goodput Note 1 0. 5 PMI recommendation upper bound -6. 4% 47. 4% gain over uncoordinated case 2 0. 5 A practical PMI restriction case -2. 6% 8. 8% gain over uncoordinated case 3 4 PMI recommendation upper bound 7. 4% 31. 8% gain over uncoordinated case < Figure 1 > Goodput vs. cdf of UB and uncoordinated cases

Simulation Results < Table 2 > Practical evaluations vs. number of rest. PMIs and/or rest. Bands case no BS antenna spacing(l) PMI coordination scheme F/B type Average sector goodput 5% edgeuser goodput note 2 0. 5 PMI restriction 3 PMIs over 3 subbands 1. 7% 6. 4% gain over case no 4 4 0. 5 PMI restriction 1 PMI over 1 subband - - gain over case no 4 (reference) 5 0. 5 PMI restriction 1 PMI over 3 subbands 0. 9% 0. 7% gain over case no 4 6 0. 5 PMI restriction 2 PMIs over 1 subband 0. 1% 1. 4% gain over case no 4 7 0. 5 PMI restriction 2 PMIs over 3 subbands 1. 5% 2. 1% gain over case no 4 8 0. 5 PMI restriction 1 PMI over 12 bands 0. 0% 3. 2% gain over case no 4 9 0. 5 PMI restriction 2 PMIs over 12 bands -0. 2% 4. 5% gain over case no 4

Conclusion • It was shown that the feedback of a set of PMIs rather than a single PMI is beneficial. An efficient procedure for feeding back a set of PMIs with 1 -bit signaling is proposed in C 80216 m-09_1625. • It was shown that the feedback for all subbands is not efficient, but that the feedback of a PMI set for a limited number of subbands is efficient. It is proposed to include the subband index as a feedback information in Table x 2 in C 80216 m-09_1540 r 1.

Proposed Text • See C 80216 m-09_1625

Additional Information on Simulations Setup

Flow of PMI Coordination Serving cell chooses N 1 (out of N_EU x N_DI) requests (based on some urgency metric such as interference), and send them to respective neighbors’ addresses. Cell A-MS 1, An edge user Cell A-MS 2, An edge user PMI 1 @ subband 1 PMI 1 @ subband 2 PMI 2 @ subband 1 PMI 2 @ subband 2 : one request from cell A -MS 1 toward each of the interfering cells ……… N_DI (interferers) x n_rest. PMI x n_rest. Band or N_DI (interferers) x n_recom. PMI x n_recom. Band N_DI: number of dominant interferers seen by each MS, n_rest. PMI: number of restrictive PMIs, n_rest. Band: number of restrictive bands n_recom. PMI: number of recommended PMIs, n_recom. Band: number of recommended bands N_EU: number of edge users per cell

Flow of PMI Coordination Subband 1 …. . Two requests Cell C accepts only N 2 requests out of all received requests, and combine them to find restrictive (or recommended) resources for its users. Cell C restricted recom Subband 1 PMI 1 One request From Cell E restricted or Subband M One request From Cell F restricted Subband M …. . One request From Cell D restricted recom recom recomm …. . PMI V

Additional Information on Simulations Setup