Transcript 11-14/1400r1

November 2014
doc.: IEEE 802. 11-14/1400r1
CSI Feedback for MIMO-OFDM Transmission
in IEEE 802.11aj (45 GHz)
Date: 2014-11-5
Presenter: Haiming Wang
Authors/contributors:
Name
Company
Address
+86-25-5209
1653-3121 (ext.)
+86-25-5209
1653-301 (ext.)
Shiwen HE
Haiming WANG
Yongming HUANG
2 Sipailou, Nanjing
Southeast
210096, China
University (SEU)
Yuanwen LI
Bo WU
Wei HONG
Bo SUN
Submission
Phone
ZTE
Email
[email protected]
[email protected]
[email protected]
n
yuanwenli.1202@gm
ail.com
[email protected]
.cn
+86-25-5209 1650 [email protected]
[email protected]
Slide 1
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
Abstract
 This presentation proposes CSI feedback schemes for transmit
beamforming in IEEE 802.11aj (45 GHz).
Submission
Slide 2
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
Introduction (1/2)
 Beamforming can improve the performance of system, including
-
Enhance throughput in IEEE 802.11n/ac
Quasi-ML detection performance can be achieved with a low-complexity
receiving structure.
-
Expand coverage in IEEE 802.11ad
By focusing transmitting power on a specific direction, signals can be
transmitted to a longer distance.
 Compressed beamforming matrix feedback based on Givens
Rotation has been used in IEEE 802.11n/ac, due to
Submission
-
Reduced feedback overhead
-
Low complexity
Slide 3
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
Introduction (2/2)
 The number of bits used for angle quantization in IEEE 802.11n and
IEEE 802.11ac
- 802.11n supports (3,1), (4,2), (5,3) or (6,4) bits to quantize angle (ϕ, ψ).
- 802.11ac supports (4,2) or (6,4) bits to quantize angle (ϕ, ψ) for single
user, and (7,5) or (9,7) bits to quantize angle (ϕ, ψ) for multi-user.
 Subcarrier grouping has been applied in IEEE 802.11n and IEEE
802.11ac to further reduce feedback amount
- 11n and 11ac both support to combine 2 or 4 subcarriers into one group.
- Appropriate interpolation method is needed to reconstruct beamforming
matrices.
Submission
Slide 4
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
Feedback scheme
 Explicit feedback is proposed for beamforming to 802.11aj (45 GHz),
including
a) CSI feedback
- Channel matrix H
b) Noncompressed Beamforming Matrix feedback
- Right singular matrix of H
c) Compressed Beamforming Matrix feedback
- Compressed right singular matrix of H
Submission
Slide 5
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
Angle Quantization
 For compressed beamforming matrix feedback based on Givens
Rotation , angles ψ and ϕ are quantized as
1 
 k
N

,
k

0,1,
,
2
1

N 1
N  2
2
2

1 
 k
N
    N 1  N ， k =0,1, , 2   1
2 
2
  
where
N
and
N
are the number of bits used to quantize ψ and ϕ respectively.
- After quantization, angle ϕ is quantized between 0 and 2π, angle ψ is
quantized between 0 and π/2.
-
Submission
N
is more than
N
by 2 bits.
Slide 6
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
Subcarrier Grouping
 For subcarrier grouping, the group size N g should satisfy
2  N g   Bc f 
where f is subcarrier frequency spacing, Bc is the coherent bandwidth of the
channel.
-
-
Submission
The RMS delay spread of 802.11aj (45 GHz) channel is 10 ns, and
f =2.578125 MHz , Bc =1  5 10 109   20 MHz ,  Bc f   7 .
Since the number of effective subcarriers is 176/352, which is even, so
optional N g set is {2, 4, 6}.
Slide 7
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
Frame Format of NDP
 Propose to use the same NDP sounding mechanism as 11ac, and the
NDP format is shown as follows.
QTF
SIG-A
MCTF 1
MCTF N
- QTF is composed of 14 ZCZ sequences
- MCTF is used to estimate channel, and N depends on the dimension of
channel matrices to be estimated.
Submission
Slide 8
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
Frame Format of NDP
 QMG NDP Announcement frame format
Octets:
Frame
Control
Duration
RA
TA
2
2
6
6
Sounding
Dialog STA Info 1
Token
1
AID12
Bits:
Feedback
Type
Nc Index
Submission
...
STA Info n
FCS
2
4
2
Feedback
Nc Index
Type
1
12
Reserved
2
1
Set to 0 for SU;
Set to 1 for MU.
If the Feedback Type field indicate MU,
then Nc Index indicates the number of
columns Nc of feedback matrix:
Set to 0 \1\2\3 to request Nc = 1\2\3\4
Reserved if the Feedback Type field
indicates SU.
Slide 9
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
Frame Format of MIMO Control
 QMG CSI/Beamforming frame format
Order
Information
1
Category
2
QMG Action
3
QMG MIMO Control
4
QMG CSI/Beamforming Report
5
MU Exclusive Noncompressed /Compressed
Beamforming Report
•
The Category field is set to 22 for QMG Action
•
The QMG Action field is set to 0 for QMG CSI,
set to 1 for QMG Noncompressed Beamforming,
set to 2 for QMG Compressed Beamforming.
•
The MU Exclusive Noncompressed/Compressed
Beamforming Report present when the Feedback
Type is MU.
 QMG MIMO Control field
B0
B1 B2
Nc
Index
Bits:
2
Submission
B3
B4
B5
B6 B7
Nr
Index
Channel
Width
Grouping
2
1
2
B8
B9
Codebook Feedback
Information
Type
2
1
Slide 10
B10
B12
Remaining
Feedback
Segments
3
B13
B14
B17 B18
B23
First
Sounding
Feedback Reserved
Dialog
Segment
Token Number
1
4
6
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
Description of MIMO Control Field
 QMG MIMO Control field description
Nc Index
Indicates the number of columns of V matrix:
Set to 0\1\2\3 for Nc=1\2\3\4
Nr Index
Indicates the number of rows of V matrix:
Set to 0\1\2\3 for Nr=1\2\3\4
Channel
Width
Indicates the channel width:
Set to 0\1 for 540\1080 MHz
Grouping
Indicates the number of carriers grouped into one:
Set to 0\1\2\3 for Ng=1\2\4\6
Indicates the number of bits in the representation of the real and imaginary parts of each element in the
matrix for QMG CSI feedback and QMG Noncompressed Beamforming feedback, or indicates the size of
codebook entries for Compressed Beamforming feedback：
Codebook
Information
Submission
For CSI feedback:
Set to 0\1\2\3 for Nb = 4\5\6\8
For Noncompressed Beamforming feedback:
Set 0\1\2\3 for Nb = 4\3\6\8
For compressed Beamforming feedback:
If Feedback Type is SU:
Set to 0 for 2 bits for ψ, 4 bits for ϕ
Set to 1 for 3 bits for ψ, 5 bits for ϕ
Slide 11
If Feedback Type is MU:
Set to 0 for 5 bits for ψ, 7 bits for ϕ
Set to 1 for 7 bits for ψ, 9 bits for ϕ
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
Simulation Settings











Channel model: 802.11aj (45 GHz) channel
Number of distinguishable paths: 25
Maximum/RMS delay spread: 100 ns/10 ns
Channel bandwidth: 540 MHz
Packet length: 4096 bytes
Number of channel realizations: 3000
Simulation antennas: 2×1, 4×1 for 1ss, 3×2, 4×2, 4×4 for 2ss, 4×3
for 3ss.
Modulation and code rate: {QPSK ½},{64QAM ⅝}
Single user, LS channel estimation, without STBC.
Actual channel estimation for receiving sounding NDP is added.
Linear spherical interpolation is applied for subcarrier grouping, and use
7 bits to quantize ϕ, 5 bits to quantize ψ.
Submission
Slide 12
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
Simulation Results
 For Givens Rotation based angle quantization, simulation show that
- Using 5 bits to quantize ϕ, 3 bits to quantize ψ could achieve the
performance of perfect beamforming matrix.
- Using 4 bits to quantize ϕ, 2 bits to quantize ψ could also achieve the
performance close to perfect beamforming matrix, with performance
loss less than 0.4 dB.
 For subcarrier grouping, simulations show that
- For N g  2 , the maximum performance loss is 1.8 dB
- For N g  4 , the maximum performance loss is 2 dB
- For N g  6 , the maximum performance loss is 2.5 dB
- For N g  8 , the maximum performance loss is 3.4 dB
Submission
Slide 13
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
Conclusions
 Two type of angle quantization are proposed to IEEE 802.11aj (45
GHz) , including
- 4 bits to quantize ϕ, 2 bits to quantize ψ .
- 5 bits to quantize ϕ, 3 bits to quantize ψ .
 Optional group size set {1, 2, 4, 6} is proposed for subcarrier
grouping in IEEE 802.11aj (45 GHz).
Submission
Slide 14
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
Reference
[1] “11-10-0332-00-00ac-csi-report-for-explicit-feedback-beamforming-in-downlink-mumimo”, Koichi Ishihara et al.
[2] “11-10-0806-01-00ac-csi-feedback-scheme-using-dct-for-explicit-beamforming”,
Koichi Ishihara et al.
[3] “11-11-1539-00-00ah-beamforming-for-11ah”,Minho Cheong et al.
[4]“11-05-1645-02-000n-preambles-beamforming-wwise-proposal”,Christopher J. Hansen
et al.
[5]"11-07-0612-02-000n-comment-resolution-csi-uncompressed-steering-matrix-feedbackbitwidth-nb",Hongyuan Zhang et al.
[6]"11-10-0586-01-00ac-time-domain-csi-report-for-explicit-feedback ", Laurent Cariou et
al.
[7]"11-10-1131-00-00ac-time-domain-csi-compression-schemes-for-explicit-beamformingin-mu-mimo",Koichi Ishihara et al.
[8]"Draft P802.11REVmc_D1.5"
[9]"Draft-802.11ac_D5.1"
Submission
Slide 15
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
APPENDIX A:
Simulation Results for Angle Quantization
Submission
Slide 16
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
PER curve,Tx=2,Rx=1,1ss,R=1/2,QPSK,540MHz
0
PER
10
SE
unquantized
QuaBit=[3,1]
QuaBit=[4,2]
QuaBit=[5,3]
QuaBit=[6,4]
QuaBit=[7,5]
QuaBit=[8,6]
N  4, N  2 can
-1
achieve performance
close to unquantized
angles, with 0.1 dB
performance loss.
10
-2
10
1
2
3
4
5
6
7
8
SNR(dB)
Submission
Slide 17
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
PER curve,Tx=2,Rx=1,1ss,R=5/8,64QAM,540MHz
0
10
SE
unquantized
QuaBit=[3,1]
QuaBit=[4,2]
QuaBit=[5,3]
QuaBit=[6,4]
QuaBit=[7,5]
QuaBit=[8,6]
PER
N  4, N  2 can
achieve performance
close to unquantized
angles, with 0.1 dB
performance loss.
-1
10
-2
10
12
Submission
13
14
15
16
17
SNR(dB)
Slide 18
18
19
20
21
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
PER curve,Tx=4,Rx=1,1ss,R=1/2,QPSK,540MHz
0
10
SE
unquantized
QuaBit=[3,1]
QuaBit=[4,2]
QuaBit=[5,3]
QuaBit=[6,4]
QuaBit=[7,5]
QuaBit=[8,6]
PER
N  4, N  2 can
achieve performance
close to unquantized
angles, with 0.1 dB
performance loss.
-1
10
-2
10
-1
Submission
0
1
2
3
4
SNR(dB)
5
Slide 19
6
7
8
9
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
PER curve,Tx=4,Rx=1,1ss,R=5/8,64QAM,540MHz
0
10
SE
unquantized
QuaBit=[3,1]
QuaBit=[4,2]
QuaBit=[5,3]
QuaBit=[6,4]
QuaBit=[7,5]
QuaBit=[8,6]
PER
N  4, N  2 can
achieve performance
close to unquantized
angles, with 0.2 dB
performance loss.
-1
10
-2
10
Submission
10
12
14
16
SNR(dB)
Slide 20
18
20
22
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
PER curve,Tx=4,Rx=2,2ss,R=1/2,QPSK,540MHz
0
10
PER
N  4, N  2 can
achieve performance
close to unquantized
angles, with 0.1 dB
performance loss.
-1
10
SE
unquantized
QuaBit=[3,1]
QuaBit=[4,2]
QuaBit=[5,3]
QuaBit=[6,4]
QuaBit=[7,5]
QuaBit=[8,6]
-2
10
2
3
4
5
6
7
8
9
SNR(dB)
Submission
Slide 21
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
PER curve,Tx=4,Rx=2,2ss,R=5/8,64QAM,540MHz
0
10
SE
unquantized
QuaBit=[3,1]
QuaBit=[4,2]
QuaBit=[5,3]
QuaBit=[6,4]
QuaBit=[7,5]
QuaBit=[8,6]
PER
N  4, N  2 can
achieve performance
close to unquantized
angles, with 0.2 dB
performance loss.
-1
10
-2
10
14
16
18
20
22
24
SNR(dB)
Submission
Slide 22
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
PER curve,Tx=4,Rx=4,2ss,R=1/2,QPSK,540MHz
0
10
SE
unquantized
QuaBit=[3,1]
QuaBit=[4,2]
QuaBit=[5,3]
QuaBit=[6,4]
QuaBit=[7,5]
QuaBit=[8,6]
PER
N  4, N  2 can
achieve performance
close to unquantized
angles, with 0.1 dB
performance loss.
-1
10
-2
10
-0.5
Submission
0
0.5
1
1.5
2
2.5
SNR(dB)
Slide 23
3
3.5
4
4.5
5
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
PER curve,Tx=4,Rx=4,2ss,R=5/8,64QAM,540MHz
0
10
SE
unquantized
QuaBit=[3,1]
QuaBit=[4,2]
QuaBit=[5,3]
QuaBit=[6,4]
QuaBit=[7,5]
QuaBit=[8,6]
PER
N  4, N  2 can
achieve performance
close to unquantized
angles, with 0.1 dB
performance loss.
-1
10
-2
10
10
11
12
13
14
15
16
17
SNR(dB)
Submission
Slide 24
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
PER curve,Tx=4,Rx=3,3ss,R=1/2,QPSK,540MHz
0
10
SE
unquantized
QuaBit=[3,1]
QuaBit=[4,2]
QuaBit=[5,3]
QuaBit=[6,4]
QuaBit=[7,5]
QuaBit=[8,6]
PER
N  4, N  2 can
achieve performance
close to unquantized
angles, with 0.1 dB
performance loss.
-1
10
-2
10
4
Submission
5
6
7
SNR(dB)
8
Slide 25
9
10
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
PER curve,Tx=4,Rx=3,3ss,R=5/8,64QAM,540MHz
0
PER
10
SE
unquantized
QuaBit=[3,1]
QuaBit=[4,2]
QuaBit=[5,3]
QuaBit=[6,4]
QuaBit=[7,5]
QuaBit=[8,6]
N  4, N  2 can
-1
10
achieve performance
close to unquantized
angles, with 0.4 dB
performance loss.
-2
10
15
Submission
16
17
18
19
20
21
SNR(dB)
22
Slide 26
23
24
25
26
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
APPENDIX B:
Simulation Results for Subcarrier Grouping
Submission
Slide 27
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
PER curve,Tx=2,Rx=1,1ss,R=1/2,QPSK,540MHz
0
PER
10
SE
no grouping
Ng=2
Ng=4
Ng=6
Ng=8
Performance loss:
Ng=2, 0.15 dB
Ng=4, 0.2 dB
Ng=6, 0.4 dB
Ng=8, 0.8 dB
-1
10
-2
10
1
2
3
4
5
6
7
8
SNR(dB)
Submission
Slide 28
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
PER curve,Tx=2,Rx=1,1ss,R=5/8,64QAM,540MHz
0
PER
10
SE
no grouping
Ng=2
Ng=4
Ng=6
Ng=8
Performance loss:
Ng=2, 0.2 dB
Ng=4, 0.3 dB
Ng=6, 0.5 dB
Ng=8, 0.9 dB
-1
10
-2
10
12
Submission
13
14
15
16
17
SNR(dB)
Slide 29
18
19
20
21
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
PER curve,Tx=4,Rx=1,1ss,R=1/2,QPSK,540MHz
0
PER
10
SE
no grouping
Ng=2
Ng=4
Ng=6
Ng=8
Performance loss:
Ng=2, 0.2 dB
Ng=4, 0.3 dB
Ng=6, 0.5 dB
Ng=8, 1 dB
-1
10
-2
10
-1
0
1
2
3
4
5
6
7
8
SNR(dB)
Submission
Slide 30
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
PER curve,Tx=4,Rx=1,1ss,R=5/8,64QAM,540MHz
0
PER
10
SE
no grouping
Ng=2
Ng=4
Ng=6
Ng=8
Performance loss:
Ng=2, 0.2 dB
Ng=4, 0.2 dB
Ng=6, 0.5 dB
Ng=8, 1 dB
-1
10
-2
10
10
12
14
16
18
20
SNR(dB)
Submission
Slide 31
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
PER curve,Tx=3,Rx=2,2ss,R=1/2,QPSK,540MHz
0
PER
10
SE
no grouping
Ng=2
Ng=4
Ng=6
Ng=8
Performance loss:
Ng=2, 0.2dB
Ng=4, 0.3 dB
Ng=6, 0.6 dB
Ng=8, 0.8 dB
-1
10
-2
10
4
Submission
5
6
7
SNR(dB)
Slide 32
8
9
10
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
PER curve,Tx=3,Rx=2,2ss,R=5/8,64QAM,540MHz
0
PER
10
SE
no grouping
Ng=2
Ng=4
Ng=6
Ng=8
Performance loss:
Ng=2, 0.3 dB
Ng=4, 0.7 dB
Ng=6, 1.3 dB
Ng=8, 2 dB
-1
10
-2
10
16
Submission
17
18
19
20
21
SNR(dB)
Slide 33
22
23
24
25
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
PER curve,Tx=4,Rx=2,2ss,R=1/2,QPSK,540MHz
0
PER
10
Performance loss:
Ng=2, 0.2 dB
Ng=4, 0.3 dB
Ng=6, 0.6 dB
Ng=8, 1 dB
-1
10
SE
no grouping
Ng=2
Ng=4
Ng=6
Ng=8
-2
10
2
3
4
5
6
7
8
9
SNR(dB)
Submission
Slide 34
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
PER curve,Tx=4,Rx=2,2ss,R=5/8,64QAM,540MHz
0
PER
10
Performance loss:
Ng=2, 0.5 dB
Ng=4, 0.8 dB
Ng=6, 1.4 dB
Ng=8, 2.1 dB
-1
10
-2
10
13
Submission
SE
no grouping
Ng=2
Ng=4
Ng=6
Ng=8
14
15
16
17
18
19
SNR(dB)
Slide 35
20
21
22
23
24
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
PER curve,Tx=4,Rx=4,2ss,R=1/2,QPSK,540MHz
0
10
PER
SE
no grouping
Ng=2
Ng=4
Ng=6
Ng=8
Performance loss:
Ng=2, 0.5 dB
Ng=4, 0.55 dB
Ng=6, 0.7 dB
Ng=8, 0.9 dB
-1
10
-2
10
-0.5
Submission
0
0.5
1
1.5
2
2.5
SNR(dB)
Slide 36
3
3.5
4
4.5
5
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
PER curve,Tx=4,Rx=4,2ss,R=5/8,64QAM,540MHz
0
PER
10
SE
no grouping
Ng=2
Ng=4
Ng=6
Ng=8
Performance loss:
Ng=2, 1 dB
Ng=4, 1.2 dB
Ng=6, 1.3 dB
Ng=8, 1.5 dB
-1
10
-2
10
10
11
12
13
14
15
16
17
SNR(dB)
Submission
Slide 37
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
PER curve,Tx=4,Rx=3,3ss,R=1/2,QPSK,540MHz
0
10
PER
SE
no grouping
Ng=2
Ng=4
Ng=6
Ng=8
Performance loss:
Ng=2, 0.6 dB
Ng=4, 0.8 dB
Ng=6, 1 dB
Ng=8, 1.3 dB
-1
10
-2
10
Submission
4
5
6
7
SNR(dB)
Slide 38
8
9
10
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
PER curve,Tx=4,Rx=3,3ss,R=5/8,64QAM,540MHz
0
PER
10
SE
no grouping
Ng=2
Ng=4
Ng=6
Ng=8
Performance loss:
Ng=2, 1.8 dB
Ng=4, 2 dB
Ng=6, 2.5 dB
Ng=8, 3.4 dB
-1
10
-2
10
15
Submission
16
17
18
19
20
21
SNR(dB)
Slide 39
22
23
24
25
26
Shiwen He, Haiming Wang
November 2014
doc.: IEEE 802. 11-14/1400r1
Thanks for Your Attention!
Submission
Slide 40
Shiwen He, Haiming Wang