stealth cognitive radio with mimo active interference cancellation and v-blast date: 2007.10.19...
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Stealth Cognitive Radio With MIMO Active Interference
Cancellation and V-BLAST
Date: 2007.10.19Speaker: 王貞傑指導教授 : 吳仁銘
Outline
• AIC• Algorithm• simulation
• V-blast• Algorithm• simulation
• MIMO-AIC
Active Interference Cancellation (AIC) Algorithm
Active Interference Cancellation (AIC) Algorithm
127
0
))(128
2exp(),(n r
lk
njklP )]1128(,0[ rl
127
0
127
0
127
0
),()(128
1
)))(128
2exp()((128
1)(
k
n k
klPkX
r
lk
njkXlY
)]1128(,0[ rl
]127,0[k
gPd 1
11 dhP
TXXXXg )]127()89(00000)83()0([ TrXrXrXrXrXd )]186()86()185()85()184([1
)88:84,186:184(1 rrPPT
XXXXXh
)88()87()86()85()84(
^^^^^
1111
1
11 dWdPPPh TT
gWPgWh 21
2
112 dhPe Minimization
Active Interference Cancellation (AIC) Simulation
0 25 50 75 100 125-300
-250
-200
-150
-100
-50
0
50
Po
we
r sp
ect
rum
subcarrier
3-tone AIC 5-tone AIC 7-tone AIC 9-tone AIC
3-tone AIC
5-tone AIC
7-tone AIC
9-tone AIC
Power Spectrum after AIC
Active Interference Cancellation (AIC) Simulation
0 25 50 75 100 125 150-300
-250
-200
-150
-100
-50
0
50Comparison of Power spectrum with AIC and Turn-off
subcarrier
pow
er m
agni
tude
(dB
)
9-tone AIC
9-tone turn-off
Outline
• AIC• Algorithm• simulation
• V-blast• Algorithm• simulation
• MIMO-AIC
Vertical Bell Laboratories Layered Space-Time (V-BLAST) Encoding
Vertical Bell Laboratories Layered Space-Time (V-BLAST) Decoding
Vertical Bell Laboratories Layered Space-Time (V-BLAST) Decoding
vaHr 1
ij
ijHw ijk
Tk ji
1
0
22
2
:symbol detectedfor SNRdetection -post
i
i
i
k
k
kw
a
},,2,1{ Mk i
ers transmittM, receivers N
MNH
Vertical Bell Laboratories Layered Space-Time (V-BLAST) Decoding
• Initialization: Recursion: 1i
HG1
2
11 )(minarg jj
Gk
ii kik Gw )(
i
H
kk rwyii
)(ˆii kk yQa
ii kkii Harr )(ˆ1
iki HG 1
2
11 )(minarg1
jikkj
i Gki
1 ii
HH HHHHG 1)(
HH HIHHG 12 )(
V-Blast Simulation
0 5 10 15 20 25 3010
-4
10-3
10-2
10-1
100
SNR(dB)
BE
R1
V-BLAST(2x2)
Outline
• AIC• Algorithm• simulation
• V-blast• Algorithm• simulation
• MIMO-AIC
MIMO-AIC• Assumptions: The channel is random, flat-fading or quasi-static, frequency independent
(but changing from frame to frame is accepted or that is to say this rule constrains inside a frame).
The channel gains, signals and noise are independent.
Perfect channel state information (CSI) should be assumed to be available at the receiver end.
We have assumed perfect timing and synchronization so that there’s no more degradation.
The noise vector is complex AWGN.
we have already known first transmitter data sequence so as to operate the AIC action at second receiver to clean interference from both transmitters.
MIMO-AIC
• Assumptions:• QPSK• Oversampling rate=4
Final oversampling rate (comparison)=20• 2x2 UWB channel ( CM1~CM4)• Tx1 :data• Tx2 :AIC (around preserved band)
data (left subcarriers)
),,,( 22211211 HHHHH
MIMO-AIC
Tx2_DATATx2_DATA
Tx1_DATATx1_DATA Tx1_Victim
Tx2_AIC
Tx1_Victim
Tx2_AIC
(2)
(1)
Tx 1 Rx 1
Tx 2 Rx 2
Tx Rx (V-BLAST)
H11
H22
H21
H12
2 x 2 MIMO AIC Architecture
Tx2_DATATx2_DATA
Tx1_DATATx1_DATA Tx1_Victim
Tx2_AIC
Frequency allocation
MIMO-AIC(1)
Tx 1 Rx 1
Tx 2 Rx 2
Tx Rx (V-BLAST)
H11
H22
H21
H12
2 x 2 MIMO AIC Architecture
Tx2_DATATx2_DATA
Tx1_DATATx1_DATA Tx1_Victim
Tx2_AIC
Frequency allocation
0 25 50 75 100 125-120
-100
-80
-60
-40
-20
0
20
40
Po
we
r sp
ect
rum
(d
B)
subcarrier
SNR=0 dB SNR=5 dB SNR=10dB SNR=15dB SNR=20dB SNR=25dB SNR=30dB
H=(CM1,CM1,CM1,CM1)
0 25 50 75 100 125-120
-100
-80
-60
-40
-20
0
20
40
po
we
r se
ctru
m(d
B)
subcarrier
SNR=0 dB SNR=5 dB SNR=10dB SNR=15dB SNR=20dB SNR=25dB SNR=30dB
H=(CM1,CM1,CM2,CM2)
0 25 50 75 100 125-120
-100
-80
-60
-40
-20
0
20
40
Pow
er s
pec
trum
(d
B)
subcarrier
SNR=0 dB SNR=5 dB SNR=10dB SNR=15dB SNR=20dB SNR=25dB SNR=30dB
H=(CM1,CM1,CM3,CM3)
0 25 50 75 100 125
-120
-100
-80
-60
-40
-20
0
20
40
Pow
er s
pect
rum
(dB
)
subcarrier
SNR=0 dB SNR=5 dB SNR=10dB SNR=15dB SNR=20dB SNR=25dB SNR=30dB
H=(CM1,CM1,CM4,CM4)
MIMO-AIC(1)
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 321E-4
1E-3
0.01
0.1
1
BE
R
SNR(dB)
Tx1_Victim (1111) Tx1_DATA (1111) Tx2_AIC (1111) Tx2_DATA (1111) Tx1_Victim (1122) Tx1_DATA (1122) Tx2_AIC (1122) Tx2_DATA (1122) Tx1_Victim (1133) Tx1_DATA (1133) Tx2_AIC (1133) Tx2_DATA (1133) Tx1_Victim (1144) Tx1_DATA (1144) Tx2_AIC (1144) Tx2_DATA (1144)
Tx2_AIC
Tx1_Victim
Tx1_DATATx2_DATA
MIMO-AIC(2)
Tx 1 Rx 1
Tx 2 Rx 2
Tx Rx (V-BLAST)
H11
H22
H21
H12
2 x 2 MIMO AIC Architecture
Protect band
Frequency allocation
Tx1_Victim
Tx2_AIC
0 25 50 75 100 125
-300
-250
-200
-150
-100
-50
0
Pow
er s
pect
rum
(dB
)
subcarrier
SNR=0 dB SNR=5 dB SNR=10dB SNR=15dB SNR=20dB SNR=25dB SNR=30dB
H=(CM1,CM1,CM1,CM1)
0 25 50 75 100 125
-300
-250
-200
-150
-100
-50
0
Po
we
r sp
ect
rum
(d
B)
subcarrier
SNR=0 dB SNR=5 dB SNR=10dB SNR=15dB SNR=20dB SNR=25dB SNR=30dB
H=(CM1,CM1,CM2,CM2)
0 25 50 75 100 125
-350
-300
-250
-200
-150
-100
-50
0
Po
we
r sp
ect
rum
(d
B)
subcarrier
SNR=0 dB SNR=5 dB SNR=10dB SNR=15dB SNR=20dB SNR=25dB SNR=30dB
H=(CM1,CM1,CM3,CM3)
0 25 50 75 100 125
-350
-300
-250
-200
-150
-100
-50
0
Po
we
r sp
ect
rum
(d
B)
subcarrier
SNR=0 dB SNR=5 dB SNR=10dB SNR=15dB SNR=20dB SNR=25dB SNR=30dB
H=(CM1,CM1,CM4,CM4)
MIMO-AIC(2)
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 321E-4
1E-3
0.01
0.1
BE
R
SNR (dB)
Tx1(1111) Tx1(1122) Tx1(1133) Tx1(1144)
More analysis for Victim part and AIC part
Tx 1 Rx 1
Tx 2 Rx 2
Tx Rx (V-BLAST)
H11
H22
H21
H12
2 x 2 MIMO AIC Architecture
Tx2_DATATx2_DATA
Tx2_Protect
Tx1_DATA Tx1_DATA
Tx1_Protect
Protect band
Frequency allocationTx1_Vitctim
Tx2_AIC
More analysis for Victim part and AIC part
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32
1E-4
1E-3
0.01
0.1
BE
R
SNR (dB)
Tx1_Victim (1111) Tx1_DATA (1111) Tx1_Protect(1111) Tx2_DATA (1111) Tx1_Victim (1122) Tx1_DATA (1122) Tx1_Protect(1122) Tx2_DATA (1122) Tx1_Victim (1133) Tx1_DATA (1133) Tx1_Protect(1133) Tx2_DATA (1133) Tx1_Victim (1144) Tx1_DATA (1144) Tx1_Protect(1144) Tx2_DATA (1144)
Tx1_Victim
Tx1_DATATx1_ProtectTx2_DATA
Reference
• H. Yamaguchi, “Active Interference Cancellation Technique for MB-OFDM Cognitive Radio,” Microwave Conference, 2004. 34th European Volume 2, pp.1105-1108, 13 Oct. 2004.
• P. W. Wolniasky, G. J. Foschini, G.D. Golden, and R. A. Valenzuela. “V-blast: An architecture for realizing very high data-rates over the rich-scattering wireless channel,” Proc. IEEE ICC-00, New Orleans, LA, USA, 18-22 June 2000.
• http://mimo.cm.nctu.edu.tw/Courses/Special_Topics_on_DSP_2007.htm, Ta-Sung Lee, Signal Processing for Wireless Communications, spring semester in 2007.