1. 1 MIMO Supports for IEEE 802.16m Broadcast Channel IEEE 802.16 Presentation Submission Template (Rev. 9) Document Number: IEEE C802.16m-08/1416r1 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 LG R&D Complex, 533 Hogye-1dong, Dongan-gu, Anyang, 431-749, Korea Venue: Re: TGm SDD: Others (In response to Call for Comments and Contributions on 16m SDD IEEE 802.16m-08/040) Purpose: This contribution proposes SDD text for BCH based on IEEE 802.16m-08/003r5. 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 Contents  MIMO Configuration Supporting BCH  Simulation Environment  Performance Comparison  Summary  Text Proposal for IEEE 802.16m SDD

3. 3 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 2 streams for the MIMO support on BCH.  The BCH performance will have dominant effects on the overall 16m performance.  If the performance of 2-stream MIMO is superior to that of 1-stream MIMO, the 2 stream MIMO scheme on BCH should be adopted.

4. 4 Simulation Environment ParametersAssumption Carrier frequency2.5GHz System bandwidth5MHz Sampling factor28/25 Sampling frequency5.6MHz Subcarrier spacing10.9375kHz FFT size512 CP configuration1/8Tu (=11.42us) Number of used/guard subcarriers432/80 Number of Tx/Rx antennas2Tx-2Rx Correlation at Tx/Rx0.0/0.0 (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 ModelPedB 3km/h, VehA 120km/h, TU 250km/h Modulation and coding rateQPSK 1/12 and 1/16 Channel codingTurbo code Channel estimationPerfect/Practical (DFT-based & 3dB boosting) Number of information bits248 Assumed number of OFDM symbols for BCH4 (1/12 code rate) and 6 (1/16 code rate)

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

6. 6 Performance Comparison  Observation  With a high antenna correlation, the 2 stream outperforms 1 stream regardless of the mobile speed.  As the antenna correlation increases, the performance gap becomes more significant (over SNR 2dB). 2.9 dB 2.2 dB 1.8 dB

7. 7 Performance Comparison (cont’d)  Observation  For a moderate antenna correlation of 0.5, the 2 stream transmission always outperforms 1 stream (over 1 dB).  Compared to a high speed of 250 km/h, performance gain of 2 stream transmission is still shown. 1.7 dB 2.0 dB 1.0 dB

8. 8 Performance Comparison (cont’d)  Observation  Even in no antenna correlation cases, the 2 stream transmission always outperforms 1 stream.

9. 9 Performance Comparison (cont’d)  Observation  Even the code rate becomes lower (repetition = 8), the 2 streams outperforms 1 stream regardless of mobile speed.

10. 10 Performance Comparison (cont’d)  Observation  As antenna correlation increases, the performance gap between 2 streams and 1 stream grows (over SNR 1dB). 1.0 dB 1.8 dB

11. 11 Summary  For BCH, the performance of 2 stream MIMO transmission is always better than that of 1 stream MIMO case.  In case of SFBC, we can expect a similar or better performance than STBC.  For ensuring robust BCH transmission, we need to modify the current SDD text from 1 stream MIMO support to 2-stream MIMO support.

12. 12 Text Proposal for IEEE 802.16m SDD ============= Start of text proposal for C80216m-08/003r5================ Modify the 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. The MS is not required to know the antenna configuration prior to decoding the BCH. … ================== End of text proposal =============================