MIMO Supports for IEEE 802 16 m Broadcast

MIMO Supports for IEEE 802. 16 m Broadcast Channel IEEE 802. 16 Presentation Submission Template (Rev. 9) Document Number: IEEE C 802. 16 m-08/1416 r 2 Date Submitted: 2008 -10 -31 Source: Jinsoo Choi, Seunghee Han, Sungho Moon, Jin Sam Kwak, Bin-chul Ihm e-mail : {emptylie, dondai, msungho, samji, bcihm}@lge. com LG Electronics Venue: Re: TGm SDD: Others (In response to Call for Comments and Contributions on 16 m SDD IEEE 802. 16 m-08/040) Purpose: This contribution proposes SDD text for BCH based on IEEE 802. 16 m-08/003 r 5. 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

Contents • MIMO Configuration Supporting BCH • Simulation Environment • Performance Comparison • Summary • Text Proposal for IEEE 802. 16 m SDD 2

MIMO Configuration Supporting BCH • Introduction – 1 stream MIMO support : CDD – 2 stream MIMO support : STBC or SFBC • Current SDD text: 1 stream MIMO support • Need to compare the performance b/w 1 stream vs. 2 stream MIMO transmissions – There was no sufficient performance comparison between 1 stream and 23 streams for the MIMO

Simulation Environment Parameters Assumption Carrier frequency 2. 5 GHz System bandwidth 5 MHz Sampling factor 28/25 Sampling frequency 5. 6 MHz Subcarrier spacing 10. 9375 k. Hz FFT size 512 CP configuration 1/8 Tu (=11. 42 us) Number of used/guard subcarriers 432/80 Number of Tx/Rx antennas 2 Tx-2 Rx Correlation at Tx/Rx 0. 0/0. 0 (uncorrelated), 0. 5/0. 5, 0. 9/0. 9 Multi-antenna transmission 1) 1 stream: CDD for BCH 2) 2 streams: STBC for BCH Channel Model Ped. B 3 km/h, Veh. A 120 km/h Modulation and coding rate QPSK 1/12 and 1/16 Channel coding Turbo code Channel estimation Perfect/Practical (DFT-based, 3 d. B pilot boosting) Number of information bits 248 Assumed number of OFDM symbols for BCH 4 (1/12 code rate) and 6 (1/16 code rate) 4

Simulation Environments (cont’d) q Assumed Pilot structure for STBC (2 Tx) q Assumed Pilot structure for CDD (2 Tx) 5

Performance Comparison • Observation – The 2 stream transmission always outperforms 1 stream. In the channel with moderate frequency selectivity, the performance gap increases. 6

Performance Comparison (cont’d) • Observation – The performance gap decreases a little compared to 1/12 code rate case. – Even the code rate becomes lower, the 2 streams still outperforms 1 stream regardless of mobile speed. 7

Performance Comparison (cont’d) • How about in antenna correlated environment? Tx / Rx 2 Stream. Correlation outperforms • Observation Correlation (0. 0 / 0. 0) (0. 5 / 0. 5) (0. 9 / 0. 9) Ped. B 3 km/h 0. 8 d. B 1. 7 d. B 2. 8 d. B Veh. A 120 km/h 1. 2 d. B 2. 0 d. B 2. 2 d. B <Performance gap with 1/12 code rate (at 1% BLER)> Tx / Rx Correlation (0. 0 / 0. 0) Tx / Rx Correlation (0. 5 / 0. 5) Ped. B 3 km/h 0. 6 d. B 1. 0 d. B Veh. A 120 km/h 1. 1 d. B 1. 8 d. B < Performance gap with 1/16 code rate (at 1% BLER)> 8 – As the antenna correlation increases, the performance gap becomes larger. – As the code rate becomes lower, the performance gap decreases a little. But 2 stream transmission still

Summary • In the evaluation, 2 stream MIMO transmission provides sufficiently good performance compared to 1 stream MIMO transmission. • In case of SFBC application for the 2 stream transmission, we can expect a similar or better performance gain than STBC transmissions. • Considering channel estimations aided by other impacts (e. g. by SCH, more pilots, etc. ), it’s obvious that 2 stream MIMO transmission has 9

Text Proposal for IEEE 802. 16 m SDD ======= Start of text proposal for C 80216 m-08/003 r 5======== Modify a sentence in line 32 of page 71 in 11. 7. 2. 2. 4 as following 11. 7. 2. 2. 4 Transmission format … The PBCH is transmitted as a single two streams. … ========= End of text proposal =============== 10