doc.:ieee 802.11-10-1301-00-00ac submission nov 2010 jun zheng, broadcomslide 1 legacy csd table for...
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doc.:IEEE 802.11-10-1301-00-00ac
Submission
Nov 2010
Jun Zheng, BroadcomSlide 1Slide 1
Legacy CSD Table for 11ACDate: 2010-11-8
Authors:Name Affiliations Address Phone email
Jun Zheng Broadcom 16340 West Bernardo Dr., San Diego, CA 92127 858-521-5315 [email protected]
Vinko Erceg Broadcom 16340 West Bernardo Dr., San Diego, CA 92127 858-521-5885 [email protected]
Sameer Vermani Qualcomm 5775 Morehouse Dr., San Diego, CA
858-845-3115 [email protected]
Hongyuan Zhang Marvell 5488 Marvell Ln, Santa Clara, CA 95054
408-222-1837 [email protected]
Eldad Perahia Intel 2111 NE 25th Ave Hillsboro, OR 97124, USA
Youhan Kim Atheros 1700 Technology Drive San Jose, CA 95110
+1-408-830-5835
Uikun Kwon Samsung San #14-1 Nongseo-dong, Giheung-gu, Yongin-si, Korea
82-10-280-9513 [email protected]
Yongho Seok LG Electronics, Inc
533, Hogye-1dong, Dongan-Gu, Anyang-Shi, Kyungki-Do, 431-749, Korea
82-31-450-1947 [email protected]
Minho Cheong ETRI 161 Gajeong-dong, Yuseong-gu, Daejeon, Korea
+82 42 860 5635
Brian Hart Cisco [email protected]
Sean Coffey
Realtek [email protected]
Vish Ponnampalam MediaTek [email protected]
George Vlantis ST-Ericsson [email protected]
Thet Htun Khine Radrix Co., Ltd. Kawazu 680-4, Iizuka, JAPAN
+81-948-29-7937
Leonardo Lanante Jr.
Kyushu Inst. of Technology
Kawazu 680-4, Iizuka, JAPAN
+81-948-29-7692
doc.:IEEE 802.11-10-1301-00-00ac
Submission
Nov 2010
Summary• Propose a methodology to design legacy CSD for 11ac
– Minimize the AGC error of the legacy portion of the frame
– Minimize the power fluctuation of the post AGC signal
• Propose to reuse the legacy CSD of 802.11n for NTX <= 4
• Optimization of legacy CSD for NTX > 5
• Propose the final legacy CSD tables for 11ac
Slide 2 Jun Zheng, Broadcom
doc.:IEEE 802.11-10-1301-00-00ac
Submission
Nov 2010
Legacy CSD for NTX <= 4
• Propose to reuse 802.11n legacy CSD for NTX <=4
Slide 3
NTX CSD values 95 percentile of the AGC error
of legacy preamblechannel model: 11nB/C/D/E
95 percentile of power difference between L-STF & VHT-STFchannel model: 11nB/C/D/E
20MHz 40MHz 80MHz 20MHz 40MHz 80MHz
1 0 0.9dB 0.6dB 0.5dB 0dB 0dB 0dB
2 0 -200 1.5dB 1.1dB 0.9dB 2.6dB 1.7dB 1.5dB
3 0 -100 -200 2.0dB 1.4dB 1.1dB 3.7dB 3.0dB 2.5dB
4 0 -50 -100 -150 2.0dB 0.9dB 0.8dB 3.8dB 2.9dB 2.5dB
Jun Zheng, Broadcom
doc.:IEEE 802.11-10-1301-00-00ac
Submission
Nov 2010
Optimization of Legacy CSD
• Assume CSDs are multiples of 25ns
• Assume CSDs are within the range of [-200ns 0ns]
• Minimize AGC error span of the legacy preamble, i.e. from 2.5% to 97.5% of the AGC error CDF of 11n channel model B/C/D/E
• In order to capture the random initial phase offset of the TX chain, 2 cases are considered
– 0 deg phase shift between even and odd TX antennas
– 180 deg phase shift between even and odd TX antennas
Slide 4 Jun Zheng, Broadcom
doc.:IEEE 802.11-10-1301-00-00ac
Submission
Nov 2010
Optimized Legacy CSD for NTX > 4
• Observations:
– AGC error of the legacy preamble is usually small
– Optimal CSD combinations are not unique
• There are more than one CSD combinations provide close to optimal performance in terms of minimizing the legacy AGC error
– Power difference between L-STF and VHT-STF could be large
Slide 5
NTX CSD values (units of ns)95 percentile of the AGC error
of legacy preamblechannel model: 11nB/C/D/E
95 percentile of power difference between L-STF &
VHT-STFchannel model: 11nB/C/D/E
20MHz 40MHz 80MHz 20MHz 40MHz 80MHz
5 0 -25 -50 -75 -100 1.3dB 0.7dB 0.5dB 10.3dB 3.6dB 2.9dB
6 0 -50 -25 -175 -150 -125 1.5dB 0.7dB 0.5dB 6.3dB 3.0dB 2.1dB
7 0 -150 -25 -100 -75 -125 -50 1.6dB 0.6dB 0.5dB 5.6dB 3.0dB 2.4dB
8 0 -25 -175 -150 -125 -100 -50 -75 1.6dB 0.7dB 0.5dB 7.9dB 3.4dB 2.7dB
Jun Zheng, Broadcom
doc.:IEEE 802.11-10-1301-00-00ac
Submission
Nov 2010
Further Optimization of Legacy CSD
• Assume CSDs are multiples of 25ns
• Assume CSDs are within the range of [-200ns 0ns]
• Only consider CSD combinations whose AGC error span of the legacy preamble is no greater than 0.1dB of the optimal CSD combination (provide in slide 5)
• Minimize the 95 percentile of the absolute power difference between L-STF and VHT-STF for 11n channel model B/C/D/E
• In order to capture the random initial phase offset of the TX chain, 2 cases are considered
– 0 deg phase shift between even and odd TX antennas
– 180 deg phase shift between even and odd TX antennas
Slide 6 Jun Zheng, Broadcom
doc.:IEEE 802.11-10-1301-00-00ac
Submission
Nov 2010
Further Optimized Legacy CSD for NTX > 4
Slide 7
NTX CSD values 95 percentile of the AGC error
of legacy preamblechannel model: 11nB/C/D/E
95 percentile of power difference between L-STF &
VHT-STFchannel model: 11nB/C/D/E
20MHz 40MHz 80MHz 20MHz 40MHz 80MHz
5 0 -175 -25 -50 -75 1.4dB 0.7dB 0.5dB 5.6dB 2.8dB 2.0dB
6 0 -200 -25 -150 -175 -125 1.6dB 0.8dB 0.5dB 4.4dB 2.5dB 1.8dB
7 0 -200 -150 -25 -175 -75 -50 1.7dB 0.7dB 0.5dB 4.8dB 2.4dB 1.9dB
8 0 -175 -150 -125 -25 -100 -50 -200 1.7dB 0.8dB 0.6dB 5.2dB 2.6dB 2.0dB
Jun Zheng, Broadcom
doc.:IEEE 802.11-10-1301-00-00ac
Submission
Nov 2010
Pre-Motion #1
• Do you support to use the following CSD table for legacy preamble and add the language provided in Appendix to Clause 3.2.3.1.1 of the IEEE Specification Framework for TGac ?
Slide 8
). of units(in
20050100251251501750
05075175251502000
00125175150252000
0007550251750
0000150100500
000002001000
0000002000
00000000
CSD nsT
802.11n Legacy CSD table
Jun Zheng, Broadcom
doc.:IEEE 802.11-10-1301-00-00ac
Submission
Nov 2010
Appendix• Cyclic shift definition:
The cyclic shift values defined in this subclause apply to the L-STF, L-LTF, L-SIG, and VHT-SIG-A of the VHT format legacy preamble.
The cyclic shift value for the portion of the packet before VHT-STF for transmitter out of total is shown in the following Table:
Slide 9
TXiCST
TXi
TXN
values for Legacy portion of the packet
Total number of transmit antennas
(NTX)
Cyclic shift for transmit antenna iTX (in units of ns)
1 2 3 4 5 6 7 8
1 0 - - - - - - -
2 0 -200 - - - - - -
3 0 -100 -200 - - - - -
4 0 -50 -100 -150 - - - -
5 0 -175 -25 -50 -75 - - -
6 0 -200 -25 -150 -175 -125 - -
7 0 -200 -150 -25 -175 -75 -50 -
8 0 -175 -150 -150 -25 -100 -50 -200
Jun Zheng, Broadcom
TXiCST