1. doc.: IEEE 802.11-10/1277r0 Submission MU-MIMO support for Heterogeneous Devices Date: 2010-11-09 Authors: Nov 2010 Slide 1Byeongwoo Kang, LG Electronics

2. doc.: IEEE 802.11-10/1277r0 Submission Potential Usage Model for MU-MIMO MU-MIMO may be able to support simultaneous multi-link peer- to-peer transmission for throughput enhancement –Various heterogeneous devices in a typical networked home scenarios (e.g. DTV, PC and handheld devices) –Each device may have different capabilities (e.g. supported channel bandwidth, MCS, FEC, etc) –It may be not typical to support MU-MIMO with all same capabilities AP STA Nov 2010 Slide 2Byeongwoo Kang, LG Electronics

3. doc.: IEEE 802.11-10/1277r0 Submission Multi-encoder Transmission for MU-MIMO (1/2) Case study –STA #1 only supports BCC decoding –STA #2 supports BCC and LDPC decoding –AP wants to pair STA #1 and #2 for MU-MIMO transmission Nov 2010 Slide 3Byeongwoo Kang, LG Electronics

4. doc.: IEEE 802.11-10/1277r0 Submission Multi-encoder Transmission for MU-MIMO (2/2) Allowing supporting STAs with different decoder capability at the AP keeps full utilization of LDPC at the STA –STA #1 uses BCC while STA #2 can utilize LDPC Considering in difficulties for vendors to support LDPC capability restricting the use cases for LDPC is not attractive –LDPC decoders typically require large gate counts in ASIC design Nov 2010 Slide 4Byeongwoo Kang, LG Electronics

5. doc.: IEEE 802.11-10/1277r0 Submission VHT-SIG design aspects Parameter design guides and consideration for VHT- SIG-A –Current specification framework document (r15) 2 bits of coding bit (1 bit dedicate to resolve number of LDPC OFDM symbols) Up to 4 simultaneous STA scheduling –For most flexible BCC and LDPC support for MU-MIMO transmissions following indication in VHT-SIG is needed 1 bit for BCC/LDPC indication for SU-MIMO 4 bits for BCC/LDPC indication for MU-MIMO (1 bit for each user respectively) Nov 2010 Slide 5Byeongwoo Kang, LG Electronics

6. doc.: IEEE 802.11-10/1277r0 Submission Proposed SIG-A2 Field Design With the propose changes AP has the flexibility to support simultaneous BCC and LDPC encoded MU-MIMO transmission –For SU-MIMO existing 1 bit can be used –For MU-MIMO existing 1 bit and 3 bits from reserved bits in SIG-A2 can be used VHT-SIG-A2 Short GI2 Set B0 to 0 for Long GI, set to 1 for Short GI Set B1 to 1 when Short GI and N sym %10 == 9 Coding2 For SU: Set B2 to 0 for BCC, set to 1 for LDPC For MU : Set B2 to 0 for BCC, set to 1 for LDPC for 1st user B3 purpose is under discussion MCS4 For SU/Broadcast/Multicast: MCS index For MU : Set B4 to 0 for BCC, set to 1 for LDPC for 2nd user Set B5 to 0 for BCC, set to 1 for LDPC for 3rd user Set B6 to 0 for BCC, set to 1 for LDPC for 4th user B7 reserved and set to 1 SU-Beamformed1 Set to 1 when packet is a SU-beamformed packet Set to 0 otherwise For MU: Reserved, set to 1 Reserved1Set to 1 CRC8CRC calculated as in 11n Section 20.3.9.4.4 with C7 in B10 Tail6All zeros Nov 2010 Slide 6Byeongwoo Kang, LG Electronics

7. doc.: IEEE 802.11-10/1277r0 Submission Pre-Motion Do you agree to redefine the VHT-SIG-A2 bit B2, B4, B5, and B6 in the specification framework document r15 to be described as following? –For SU: B2: Set to 0 for BCC, 1 for LDPC –For MU: B2: Set to 0 for BCC, 1 for LDPC for the 1st user B4: Set to 0 for BCC, 1 for LDPC for the 2nd user B5: Set to 0 for BCC, 1 for LDPC for the 3rd user B6: Set to 0 for BCC, 1 for LDPC for the 4th user –Note: if user 1, 2, 3, and/or 4 has 0 Nsts value, then corresponding bit is reserved and set to 1 –Yes: No: Abstain: Nov 2010 Slide 7Byeongwoo Kang, LG Electronics