1. SIG Fields Design of Long Preamble
Month Year
doc.: IEEE yy/xxxxr0
July 2012
SIG Fields Design of Long Preamble
Date:
Authors:
Yongho Seok, LG Electronics
John Doe, Some Company

2. Authors: July 2012 Month Year doc.: IEEE 802.11-yy/xxxxr0
Yongho Seok, LG Electronics
John Doe, Some Company

3. July 2012
Authors:
Yongho Seok, LG Electronics

4. July 2012
Motivation
In IEEE TGah meeting, the preamble names has been changed from SU/MU preamble to Short/Long preamble
However, SIG fields table (R E ) has not been correctly updated
Because TGah supports three preamble formats for >=2 MHz PHY, SIG field table also should be updated with three SIG field columns
Yongho Seok, LG Electronics

5. Beam-change Indication
July 2012
Proposal for R E.1
Short preamble
Long preamble SU MU
SU/MU Indication - 1
Length / Duration 9
MCS 4 BW 2
Aggregation
STBC
Coding 5
SGI
GID 6
Nsts 8
PAID
Ack Indication
Smoothing
Beam-change Indication
Reserved 3
CRC
Tail
Total 48 SU MU
Length / Duration 9
MCS 4 BW 2
Aggregation 1
STBC
Coding 5
SGI
GID 6
Nsts 8
PAID
Ack Indication
2  
Reserved
CRC
Tail
Total 48
Yongho Seok, LG Electronics

6. Proposal for R.3.2.1.1.E.1 Changes
July 2012
Proposal for R E.1
Changes
Smoothing/Bean-change Indication field is included in SIGA [1]
SU/MU Indication field is used in Long preamble for indicating the SU/MU frame type
Yongho Seok, LG Electronics

7. July 2012
Definition of SIG-B
SIG-B is used in the long preamble to convey the MCS information for MU-MIMO transmission (different MCS for different users).
We propose to re-define this symbol for SU transmission as an exact repetition of D-LTF1. This will enable improved channel estimation for the important cases of SU beamforming or open loop with one spatial stream (and to a lesser extent multiple streams). BW
2 MHz
4 MHz
8 MHz
16 MHz
MCS 4
Tail 6
CRC 8
Reserved 9 11
Total 26 27 29 BW
2 MHz
4 MHz
8 MHz
16 MHz
Reserved 26 27 29
Total
<SU>
<MU>
Yongho Seok, LG Electronics

8. Definition of SIG-B Proposals
July 2012
Definition of SIG-B
Proposals
R E bullet 2: replace “2MHz SIGB (long preamble)” with “For MU-MIMO transmission the 2MHz SIGB content is as shown in the following table. For SU-MIMO transmission the SIGB symbol is identical to D-LTF1.”
R.3.2.A bullet 4: replace the sentence starting with “n=0,1,2,…is the symbol index” with “n=0,1,2,…is the symbol index, continuously counted from the 1st Data symbol for short preamble and long preamble when in SU mode, and from SIGB for long preamble when in MU mode”
R D: The draft specification shall use the 4 LSB of the 11n HTSIG field 8-bit CRC for the 4-bit CRC in 11ah 2MHz and 1MHz SIG(A) fields, and use the same 11n HTSIG field 8-bit CRC in SIGB field of the >=2MHz long preamble when in MU mode
Yongho Seok, LG Electronics

9. July 2012
References
[1] IEEE /0825r0, Smoothing bit and beam_change indication bit
Yongho Seok, LG Electronics

10. Beam-change Indication
July 2012
Straw Poll 1
Short preamble
Long preamble SU MU
SU/MU Indication - 1
Length / Duration 9
MCS 4 BW 2
Aggregation
STBC
Coding 5
SGI
GID 6
Nsts 8
PAID
Ack Indication
2  
Smoothing
Beam-change Indication
Reserved 3
CRC
Tail
Total 48
Do you support the following SIGA fields design for >= 2MHz PHY?
Yongho Seok, LG Electronics

11. July 2012
Straw Poll 2
Do you support the following modification of SIGB fields for >= 2MHz PHY?
R E bullet 2: replace “2MHz SIGB (long preamble)” with “For MU-MIMO transmission the 2MHz SIGB content is as shown in the following table. For SU-MIMO transmission the SIGB symbol is identical to D-LTF1.”
R.3.2.A bullet 4: replace the sentence starting with “n=0,1,2,…is the symbol index” with “n=0,1,2,…is the symbol index, continuously counted from the 1st Data symbol for short preamble and long preamble when in SU mode, and from SIGB for long preamble when in MU mode”
R D: The draft specification shall use the 4 LSB of the 11n HTSIG field 8-bit CRC for the 4-bit CRC in 11ah 2MHz and 1MHz SIG(A) fields, and use the same 11n HTSIG field 8-bit CRC in SIGB field of the >=2MHz long preamble when in MU mode
Yongho Seok, LG Electronics