Investigation on One- and Two-Stream BCH MIMO Schemes Document Number: IEEE C80216m-09/0122r1 Date Submitted: 2009-1-8 Source: Debdeep Chatterjee, Yi Hsuan, Senjie Zhang, Jiacheng Wang, Hujun Yin, Yang-seok Choi Email: {debdeep.chatterjee@intel.com, yi.hsuan@intel.com, senjie.zhang@intel.com, jiacheng.wang@intel.com, hujun.yin@intel.com, yang-seok.choi@intel.com } Intel Corporation Venue: IEEE Session #59, San Diego, US. Re: TGm SDD section 11.7.2.2.4 Base Contribution: N/A Purpose: For TGm discussion and adoption of 802.16m SDD 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: <http://standards.ieee.org/guides/bylaws/sect6-7.html#6> and <http://standards.ieee.org/guides/opman/sect6.html#6.3>. Further information is located at <http://standards.ieee.org/board/pat/pat-material.html> and <http://standards.ieee.org/board/pat >.

Overview The current SDD text on multiple antenna schemes for BCH says “Transmission of PBCH and SBCH as one stream or two streams is FFS”. In C80216m-08_1474, we compared the performance of random beamforming vs. SFBC + random beamforming using four Tx antennas. The results show 2 two streams MIMO (SFBC + random beamforming) has better performance in most scenarios. This contribution is to compare BCH performance using either random beamforming (one-stream) or SFBC (two-stream) with two Tx antennas. We have also proposed new SDD text based on our investigation results.

Evaluated Scenarios Antenna Scheme: Diversity schemes: 2Tx and 2Rx antennas Diversity schemes: Random beamforming (RBF) SFBC Antenna correlation: High correlation Tx antenna case (0.5 lambda antenna spacing) Low correlation Tx antenna case (4 lambda antenna spacing) Uncorrelated Rx antenna Traffic model: eITU-PedB 3 km/h eITU-VehA 120 km/h

Additional Simulation Parameters Bandwidth: 10 MHz Carrier frequency: 2.5 GHz Number of information bits: 48 Modulation and Coding: QPSK ½ CC with 8 repetitions Channel estimation: PRU based MMSE Resource: Distributed LRU MIMO receiver: MMSE Angle of Departure (AoD): -600, -300, 00, 300, 600 Results are averaged over different AoD values Pilots: The two-stream pilot pattern, as in SDD, is used for both SFBC and RBF, that is, both MIMO schemes use 12 pilot tones per PRU For SFBC, each antenna boosts its pilot tone by 5dB. Effective pilot boosting at the receiver is 2dB For RBF, each antenna boosts the pilot tone by 2dB. Effective pilot boosting at the receiver is 2dB

Simulation Results: 2x2 SFBC vs Simulation Results: 2x2 SFBC vs. RBF, Noise-Limited Scenario, Low Tx Antenna Correlation

Simulation Results: 2x2 SFBC vs Simulation Results: 2x2 SFBC vs. RBF, Noise-Limited Scenario, High Tx Antenna Correlation

Simulation Results: 2x2 SFBC vs Simulation Results: 2x2 SFBC vs. RBF, Interference-Limited Scenario, Low Tx Antenna Correlation

Simulation Results: 2x2 SFBC vs Simulation Results: 2x2 SFBC vs. RBF, Interference-Limited Scenario, High Tx Antenna Correlation

Conclusion Averaged over different AoD values, SFBC has better overall performance than RBF For low transmit antenna correlation cases, the performances of the two MIMO schemes are close to each other, with SFBC performance slightly better than RBF For high transmit antenna correlation cases, in general, the performance gaps between SFBC and RBF are wider than those for low transmit antenna correlation cases We propose to use SFBC for BCH MIMO transmission in two Tx antenna configuration and SFBC plus precoding in more than two Tx antenna configurations.

Proposed SDD Text Change: Replace the following sentence on page 92, line 13 and 14 of 11.7.2.2.4 “Transmission of PBCH and SBCH as one stream or two streams is FFS.” with “PBCH and SBCH are transmitted using SFBC with two Tx antennas configuration. For more than two Tx antenna configuration, PBCH and SBCH are transmitted using SFBC plus precoding.”