doc.: ieee 802.11-yy/0847r0 submission slide 1leonardo lanante, ochi lab, kit july 2009 ieee802.11ac...
TRANSCRIPT
doc.: IEEE 802.11-yy/0847r0
Submission Slide 1 Leonardo Lanante, Ochi Lab, KIT
July 2009
IEEE802.11ac Preamble with Legacy 802.11a/n Backward Compatibility
Date: 2009-07-14Name Affiliations Address Phone email Leonardo Lanante Kyushu Institute
of Technology Kawazu 680-4, Iizuka, JAPAN
+81-948-29-7692 [email protected]
Wahyul Amien Syafei
Kyushu Institute of Technology
Kawazu 680-4, Iizuka, JAPAN
+81-948-29-7692 [email protected]
Yuhei Nagao Kyushu Institute of Technology
Kawazu 680-4, Iizuka, JAPAN
+81-948-29-7692 [email protected]
Shingo Yoshizawa Hokkaido University
Kita 14-jo Nishi 9-chome, Kita-ku, Sapporo, JAPAN
+81-11-706-6492 [email protected]
Hiroshi Ochi Radrix Corp. Kawazu 680-4, Iizuka, JAPAN
+81-948-29-7692 [email protected]
Authors:
doc.: IEEE 802.11-yy/0847r0
Submission Slide 2 Leonardo Lanante, Ochi Lab, KIT
July 2009
Outline
I. Introduction
II. Proposed Preamble Format
III. Preamble Waveform
IV. PAPR
V. Preamble Efficiency
doc.: IEEE 802.11-yy/0847r0
Submission Slide 3 Leonardo Lanante, Ochi Lab, KIT
July 2009
I. IntroductionFunctional requirements for TGac.
A) System Performance1. Shall operate in 5GHz frequency band
2. At least 1Gbps at MAC SAPs utilizing 80MHz
3. At least 500Mbps for Single STA
4. Spectral efficiency at least 7.5 bps/Hz
B) Shall ensure backward compatibility with IEEE 802.11a/n.
C) Enable coexistence and spectrum sharing with IEEE 802.11a/n.
D) Compliance to PAR
Doc.IEEE802.11-09/0304r0 March 2009
doc.: IEEE 802.11-yy/0847r0
Submission Slide 4 Leonardo Lanante, Ochi Lab, KIT
July 2009
II. Proposed Preamble
• Main Features– Uses 80MHz channel and meets all functional
requirements for a VHT preamble– Three preamble modes to minimize overhead– Seamless upgrade from 802.11n preamble– Almost identical PAPR characteristics with
802.11n– Comparable Preamble Efficiency to 802.11n
doc.: IEEE 802.11-yy/0847r0
Submission Slide 5 Leonardo Lanante, Ochi Lab, KIT
July 2009
Proposed Preamble Modes
A) Mixed 11a/n Mode1. 56us duration
2. Backward compatible with 802.11a/n
B) Mixed 11n Mode1. 44us duration
2. Backward compatible with 802.11n
C) VHT Greenfield Mode1. 36us duration
2. VHT only mode
doc.: IEEE 802.11-yy/0847r0
Submission Slide 6 Leonardo Lanante, Ochi Lab, KIT
July 2009
A) Mixed 11a/n Mode Frame FormatProposed Mixed 11a/n mode: Backward compatible with IEEE802.11a/n
Duration=56μs *
L-STFL-STF L-LTFL-LTF L-SIGL-SIG HT-SIGHT-SIG VHT-SIGVHT-SIG VHT STFVHT STF
VHT LTF1VHT LTF1
VHTLTF4VHTLTF4
DataData DataData
8μs 8μs 4μs 8μs 8μs 4μs 4μs per LTF 4/3.6μs per Data
* 4 spatial streams
L-STFL-STF L-LTFL-LTF L-SIGL-SIG HT-SIGHT-SIG HT STFHT STF
HT LTF1HT
LTF1HT
LTF4HT
LTF4DataData DataData
8μs 8μs 4μs 8μs 4μs 4μs per LTF 4/3.6μs per Data
Duration=48μs *
802.11n Mixed Mode Preamble
A New SIG field is defined to accommodate changes in VHT while maintaining compatibility
doc.: IEEE 802.11-yy/0847r0
Submission Slide 7 Leonardo Lanante, Ochi Lab, KIT
July 2009
Proposed Phase Rotation for 80 MHz Channel to Maintain Low PAPR
S
0-64 64-128 127
jS S jS
S
630-64
jS
802.11n 40Mhz case
Proposed scheme for 80Mhz
S = subcarrier pattern for 802.11a system
-This phase rotation scheme is used for all preamble symbols-The phases were chosen to give lowest PAPR
doc.: IEEE 802.11-yy/0847r0
Submission Slide 8 Leonardo Lanante, Ochi Lab, KIT
July 2009
4
jeA 2.
jeA 12
5
.
jeA 12
11
.
jeA
Subcarriers #0-64 64-128 127
L-STF 20MHz
STS3
s8 s
s0.8s
STS4STS1 STS2 STS5 STS6 STS7 STS8 STS9 STS10
SOP AGC Frame synch. Frequency synch.
4
jeA 2.
jeA 12
5
.
jeA 12
11
.
jeA
Subcarriers #0-64 64-128 127
L-STF 20MHz
STS3
s8 s
s0.8s
STS4STS1 STS2 STS5 STS6 STS7 STS8 STS9 STS10
SOP AGC Frame synch. Frequency synch.
STS3
s8 s
s0.8s
STS4STS1 STS2 STS5 STS6 STS7 STS8 STS9 STS10
SOP AGC Frame synch. Frequency synch.
Legacy – Short Training FieldL-STFL-STF L-LTF L-SIG HT-SIG VHT-SIG VHT
STFVHT LTF1
VHTLTF4
Data Data
S jS S jS
Subcarriers #
0-64 64-128 127
1 for 64
64 0
1 0 64
64
k
k
j k
k
j k
L-STF 20MHz
doc.: IEEE 802.11-yy/0847r0
Submission Slide 9 Leonardo Lanante, Ochi Lab, KIT
July 2009
Legacy - Long Training Field
A 2.jeA 12
5
.
jeA 12
11
.
jeA
Subcarriers #0-64 64-128 127
LTF1_1
L-LTF 20MHz
LTF1_2GI
s3.2 ss3.2 ss1.6 s
LTFsGI
s3.2 ss0.8 s
…
A 2.jeA 12
5
.
jeA 12
11
.
jeA
Subcarriers #0-64 64-128 127
LTF1_1
L-LTF 20MHz
LTF1_2GI
s3.2 ss3.2 ss1.6 s
LTFsGI
s3.2 ss0.8 s
…
S jS S jS
Subcarriers #
0-64 64-128 127
L-STF L-LTF L-SIG HT-SIG VHT-SIG VHT STF
VHT LTF1
VHTLTF4
Data Data
L-LTF 20MHz
doc.: IEEE 802.11-yy/0847r0
Submission Slide 10 Leonardo Lanante, Ochi Lab, KIT
July 2009
Legacy - SIGNAL Field
S jS S jS
Subcarriers #
0-64 64-128 127
L-SIG 20MHz
L-SIGGI
s3.2 ss0.8 s
L-STF L-LTF L-SIG HT-SIG VHT-SIG VHT STF
VHT LTF1
VHTLTF4
Data Data
doc.: IEEE 802.11-yy/0847r0
Submission Slide 11 Leonardo Lanante, Ochi Lab, KIT
July 2009
VHT – SIGNAL Field
MSB
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
MCS LENGTHB
WLSB LSB MSB
VHT-SIG1
VHT-SIG2
Smoo
thin
gN
o So
undi
ngA
ggre
gatio
n
LDPC
Cod
ing
Num
ber o
f Ext
ensi
onSp
atia
l str
eam
s
CRC
C7 C0
SIGNAL TAIL
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Res
erve
d on
e
Shor
t GI
64 options of MCS. 131072 octet of data LENGTH = 2 X 802.11n. CRC protected.
STB
C
Shor
t GI
Res
erve
d on
e
STB
C
BW LSBBWMSB
LENGTH should be increased by one bit to
maintain preamble efficiency lost with the use
of 80MHz channel
doc.: IEEE 802.11-yy/0847r0
Submission Slide 12 Leonardo Lanante, Ochi Lab, KIT
July 2009
B) Mixed 11n Mode Frame Format
HT mode: Backward compatibility with IEEE802.11n
Duration=44μs *
HT-STFHT-STF HT-LTFHT-LTF HT-SIGHT-SIG VHT-SIGVHT-SIG VHT LTF2VHT LTF2
VHTLTF4VHTLTF4
DataData DataData
8μs 8μs 8μs 8μs 4μs per LTF 4/3.6μs per Data
The difference with 802.11n greenfield preamble is the
additional SIG symbol
802.11n Greenfield Preamble
Duration=36μs *
HT-STFHT-STF HT-LTF1HT-LTF1 HT-SIGHT-SIG HT LTF2HT
LTF2HT
LTF4HT
LTF4DataData DataData
8μs 8μs 8μs 4μs per LTF 4/3.6μs per Data
* 4 spatial streams
doc.: IEEE 802.11-yy/0847r0
Submission Slide 13 Leonardo Lanante, Ochi Lab, KIT
July 2009
C) VHT Greenfield Mode Frame FormatGreenfield mode: No backward compatibility with IEEE802.11a/n
Duration=36μs*
VHT-STFVHT-STF VHT-LTF1VHT-LTF1 VHT-SIGVHT-SIG VHT LTF2VHT LTF2
VHTLTF4VHTLTF4
DataData DataData
8μs 8μs 8μs 4μs per LTF 4/3.6μs per Data
-Same purpose as the 802.11n greenfield format preamble
doc.: IEEE 802.11-yy/0847r0
Submission Slide 14 Leonardo Lanante, Ochi Lab, KIT
July 2009
III. Preamble Waveform
0 4 8 16 20 24 28 32 36 40 44 48 52 56 600
0.5
1
1.5
2
2.5
sTime ( )
L-STF L-LTFVHT-STF
VHT-LTF1
VHT-LTF2
VHT-LTF3
VHT-LTF4
L-SIG
HT-SIG1
HT-SIG2
VHT-SIG1
VHT-SIG2
doc.: IEEE 802.11-yy/0847r0
Submission Slide 15 Leonardo Lanante, Ochi Lab, KIT
July 2009
V. Preamble Efficiency
131072131072131072
230230
230 94.2696.43
95.4396.23
95.29
The preamble efficiency is defined as
3648
564436
%100
PREAMBLESYMSYM
SYMSYM
TNTNT
doc.: IEEE 802.11-yy/0847r0
Submission Slide 16 Leonardo Lanante, Ochi Lab, KIT
July 2009
IV. PAPR
doc.: IEEE 802.11-yy/0847r0
Submission Slide 17 Leonardo Lanante, Ochi Lab, KIT
July 2009
Conclusion
• We have been developing an 80MHz BW WLAN preamble which has backward compatibility with IEEE802.11a/n system.
• The proposed preamble has comparable efficiency compared to IEEE802.11n’s preamble.
• The proposed preamble has comparable PAPR with IEEE802.11n’s preamble.
doc.: IEEE 802.11-yy/0847r0
Submission Slide 18 Leonardo Lanante, Ochi Lab, KIT
July 2009
References
1. E. Perahia, ”IEEE P802.11 Wireless LANs: VHT below 6GHz PAR Plus 5C’s”, doc.:IEEE 802.11-08/0807r4.
2. ”Supplement to IEEE STANDARD for Information Technology – Telecommunications and Information Exchange between Systems - Local and Metropolitan Area Networks - Specific Requirements”, IEEE Std 802.11a- 1999(R2003), June 2003.
3. ”Draft STANDARD for Information Technology – Telecommunications and Information Exchange between Systems - Local and Metropolitan Area Networks - Specific Requirements”, IEEE P802.11n./D9.0, March 2009.
4. Peter L and Minho C, ”TGac Functional Requirements Rev.0”, doc.:IEEE 802.11-09/0304r0.
5. Rolf de V, ”802.11ac Usage Models Document”, doc.:IEEE802.11- 09/0161r2.
6. Minho C and Peter L, ”Proposal for TGac Evaluation Methodology”, doc.:IEEE802.11-09/0376r1.