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HAL Id: tel-01807651

https://tel.archives-ouvertes.fr/tel-01807651

Submitted on 5 Jun 2018

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Spectrum sensing for half and full-duplex interweave cognitive radio systems

Abbass Nasser

To cite this version:

Abbass Nasser. Spectrum sensing for half and full-duplex interweave cognitive radio systems. Physics

[physics]. Université de Bretagne occidentale - Brest, 2017. English. �NNT : 2017BRES0006�. �tel-

01807651�

(2)

THÈSE / UNIVERSITÉ DE BRETAGNE OCCIDENTALE

sous le sceau de l’Université Bretagne Loire pour obtenir le titre de DOCTEUR DE L’UNIVERSITÉ DE BRETAGNE OCCIDENTALE Mention : Sciences et Technologies de l’Information et de la

Communication École Doctorale SICMA

présentée par

Abbass NASSER

Préparée au Lab-STICC UMR CNRS 6285 à l'UBO & Ensta-Bretagne

Spectrum Sensing for Half and Full-Duplex Interweave Cognitive Radio Systems

Thèse soutenue le 17 janvier 2017 devant le jury composé de :

M. Christian Jutten

Professeur, Université Joseph Fourier, Examinateur

M. Gilles Burel

Professeur, Université de Bretagne Occidentale, Examinateur

M. Karim Abed Meraim

Professor, Université d'Orléans, Rapporteur

M. Yannick Deville

Professeur, Université Paul Sabatier Toulouse 3, Rapporteur

M. Koffi-Clément Yao,

Maitre de Conférence, Université de Bretagne Occidentale, Encadrant

M. Ali Mansour,

Professeur, Ensta-Bretagne, Directeur de thèse M. H. Charara,

Maitre de Conférence, Université Libanaise, Membre invité

(3)
(4)

&

(5)

etc

(6)
(7)
(8)
(9)
(10)

Tp Tp Tp Tor

Tav

(11)

Tp H0 Tp H1

(12)

f(T S|H0) f(T S|H1)

(pf a;pd) = (0.1; 09) (pf a;pd) = (0.1; 09) ρ

pf a = 0.1 pmd= 1−pd

pf a= 0.1

pmd= 1−pd pf a = 0.05

pmd= 1−pd pf a = 0.05

N = 10000 Ns

Ns = 3

(13)

Ns −12dB N = 1500

N = 1000

pf a= 0.1 Ns

Ns= 4 8

=−5 (pf a;pd) = (0.1; 0.9)

pd pf a = 0.1

H0 H1

pd = 0.9 pf a = 0.1

γd γs δ

(pHf a ; pHd) = (0.1 ; 0.9)

i.e.

Ts Tt

pd Nt

pd Nt

(14)

ppd

pf a N = 1500 Ns= 4 ppd

pf a −10 Ns= 4

(15)
(16)
(17)
(18)
(19)
(20)
(21)
(22)

etc.

%

etc

(23)
(24)
(25)

Spectrum Spectrum Spectrum PU

SU

(a): Undelay Access (b): Overlay Access (c): Interweave Access

(26)
(27)
(28)
(29)

Radio Environment

Spectrum Sensing

Spectrum Decision Spectrum Mobility

Spectrum Sharing

etc

(30)
(31)

etc

(32)
(33)
(34)

S

S&T

T S T S T

S&T S&T

SU is idle SU is idle SU is idle

(a): HD-CR

(b): FD-CR

SU is active SU is active SU is active

If PU is absent If PU is absent

If PU is absent If PU is absent

H

0

H

1

y(n)

(35)

8

<

:

H

0

: y(n) = w(n)

H

1

: y(n) = hs(n) + w(n)

h s(n) w(n) = w

p

(n) +

iw

q

(n) i.i.d

i.e. E[w(n)] = 0 = E[w

2

(n)] E[.]

w

p

(n) w

q

(n) w(n)

E[w

2p

(n)] = E[w

2q

(n)] = σ

w2

2

σ

w2

= E[ | w(n) |

2

] s(n)

γ γ = | h |

2

σ

w2

8

<

:

H

0

: y(n) = x

g

(n) + w(n)

H

1

: y(n) = hs(n) + x

g

(n) + w(n)

x

g

(n) x(n) R

X

x(n) T

X

x

g

(n)

T

X

R

X

R

X

ˆ

x

g

(n) x

g

(n) y(n) y(n) ˆ

ˆ y(n)

ˆ

y(n) = y(n) − x ˆ

g

(n)

i.e. x ˆ

g

(n) = x

g

(n) y(n) = ˆ y(n)

(36)

OX ADC Evaluation of TS

LNA Comparison with a pre-

determined threshold

Decision

� � � �

y(t)

y(n)

T

X

R

X

(37)

PU CR

PU signal

Self-Interference

PU

transmitting antenna

� � >>d

etc

etc

(38)

λ 8

<

:

H

0

: T S < λ : P U is idle

H

1

: T S ≥ λ : P U is transmitting

p

re

p

re

= P r

T S < λ | H

0

p

f a

p

f a

= P r

T S ≥ λ | H

0

p

d

p

d

= P r

T S ≥ λ | H

1

(39)

p

md

p

md

= P r

T S < λ | H

1

p

re

+ p

f a

= 1 p

d

+ p

md

= 1

H

0

H

1

H

0

p

f a

= 0.1 p

d

= 0.9

p

f a

� �� � )

� �� � ) Reject

Missed Detection

False Alarm

Detection

f(T S|H0) f(T S|H1)

(40)

H

0

H

1

p

d

p

f a

T

ED

N λ

T

ED

= 1 N

X

N n=1

| y(n) |

2

λ p

f a

H

0

p

f a

T

ED

H

0

χ

2

2N T

ED

T

ED H0

⇠ N (µ

ED0

, V

0ED

)

Hi

⇠ H

i

, i 2 { 0, 1 } N (µ, V )

µ V

(41)

H

1

T

ED

s(n) w(n) s(n) T

ED

H

1

T

ED H

⇠ N

1

ED1

, V

1ED

)

N

p

EDf a

= Q λ − σ

w2

p1 N

σ

w2

!

p

EDd

= Q λ − (σ

w2

+ σ

s2

)

p1

N

w2

+ σ

2w

)

!

Q(x)

Q(x) = 1 p 2π

Z

+1 x

e

u2

du λ

λ = 1

p N Q

1

(p

f a

w2

+ σ

w2

λ

(42)

s(n) = X

k

b

k

g(n − kN

s

)

b

k

g(n) N

s

≥ 1

r

ss

(m) s(n) m

r

ss

(m) = E[s(n)s

(n − m)] 6 = 0

etc r

ss

(m)

r

ss

(m) = 8

> >

<

> >

:

σ

s2

1 − | m | N

s

!

; | m |  N

s

0; | m | > N

s

σ

s2

= E[ | s(n) |

2

]

r

yy

(m) y(n)

r

yy

(m) = E[y(n)y

(n − m)]

= E

"

(hs(n) + w(n))(hs(n − m) + w(n − m))

#

= E

"

| h |

2

s(n)s

(n − m)

# + E

"

w(n)w

(n − m)

#

+ E

"

h

w(n)s

(n − m)

# + E

"

hw

(n − m)s(n)

#

w(n)

E[w(n)w

(n − m)] = σ

w2

δ(m)

δ(m)

δ(m) = 8

<

:

1 if m = 0

0 elsewhere

(43)

s(n) w(n) E[h

w(n)s

(n − m)] + E[hw

(n − m)s(n)] = 0

r

yy

(m) = E

"

| h |

2

s(n)s

(n − m)

#

+ E [w(n)w

(n − m)]

= | h |

2

r

ss

(m) + σ

2w

δ(m)

r

yy

(m) m 6 = 0

1  m  N

s

1  m  N

s

r

yy

(m) = 8

<

:

0 under H

0

6

= 0 under H

1

{ r

yy

(m) } m 2 [1; N

s

− 1] T

ACD

T

ACD

= 1 ˆ r

yy

(0)

Ns1

X

m=1

c

m

Re { r ˆ

yy

(m) }

Re { . } ˆ r

yy

(m) =

N1

P

N

n=1

y(n)y

(n − m)

r

yy

(m) c

m

r ˆ

yy

(0)

ˆ r

yy

(0)

H

0

p

ACDf a

= Q λ s N

λ

2

+ ϕ

!

p

ACDd

= Q λ −

γ+1βγ

p V

ACD

!

(44)

ϕ = 1 2

Ns1

X

l=1

c

2l

β =

Ns1

X

l=1

c

l

r

ss

(l)

r

ss

(0) V

ACD

= (1 + γ)λ

2

− 4βγλ + Σ + ηγ N (γ + 1)

2

η =

Ns1

X

l=1 Ns1

X

k=1;l6=k

c

l

c

k

r

ss

(l − k) + r

ss

(l + k)

r

ss

(0) γ

etc

s(n) T

α

r

ss

(n, m) = E[s(n)s

(n − m)] = r

ss

(n + T

α

, m)

r

ss

(n, m) n

r

ss

(n, m) = X

1 p=−1

R

ss

p T

α

, m

!

exp j2π p T

α

n

!

R

ss

(

Tp

α

, m) {

Tpα

}

R

ss

(α, m)

R

ss

(α, m) = lim

N−!+1

1 N

N

X

2

n=N2

s(n)s

(n − m)) exp ( − j2παn)

R

ss

(α, m) 6 = 0 α 2 {

Tpα

} α α = 0 R(0, m)

m = 0 α = 0 R

ss

(0, 0)

s(n)

(45)

R

yy

(α, m)

R

yy

(α, m) = lim

N−!1

N

X

2

n=N2

y(n)y

(n − m) exp ( − j2παn)

= lim

N−!1

N

X

2

n=N2

hs(n) + w(n)

!

h

s

(n − m) + w

(n − m)

!

exp ( − j2παn)

= lim

N−!1

Ni

X

2

n=N2

| h |

2

s(n)s

(n − m) + w(n)w

(n − m) + s(n)w

(n − m)

+ w(n)s

(n − m)

!

exp ( − j2παn)

= R

ss

(α, m) + R

ww

(α, m) + R

sw

(α, m) + R

ws

(α, m)

w(n) R

ww

(α, m) = 0 8 α 6 = 0

R

ws

(α, m) = R

sw

(α, m) = 0 s(n)

w(n)

R

yy

(α, m) = R

ss

(α, m)

R

yy

(α, m) R ˆ

yy

(α, m)

R ˆ

yy

(α, m) ' 1 N

N 21

X

n=N2

y(n)y

(n − m) exp ( − j2παn)

T

CAF

R ˆ

yy

(α, m)

T

CAF

= | R ˆ

yy

(α, m) |

2

T

CAF

(46)

T

CSD

= N r ˆ

y

r ˆ

yT

T r ˆ

y

ˆ r

y

=

"

Re { R ˆ

yy

(α, m

1

) } , Re { R ˆ

yy

(α, m

2

) } ..., Re { R ˆ

yy

(α, m

M

) } , Im { R ˆ

yy

(α, m

1

) } , Im { R ˆ

yy

(α, m

2

) } ..., Im { R ˆ

yy

(α, m

M

) }

#

Re { . } Im { . } M

= 1 2

"

Re {P + U} Im {U − P}

Im {P + U} Re {P − U}

#

1

P = P

pq

!

U = U

pq

!

P

p,q

=

L−1

X

2

l=12L

f (l) ˆ R

yy

α + 2πl N , m

p

!

R ˆ

yy

α + 2πl N , m

q

!

U

p,q

=

L1

X

2

l=1−2L

f (l) ˆ R

yy

α + 2πl N , m

p

!

R ˆ

yy

α − 2πm N , m

q

!

L f (l) P

L

l=1

f(l) = 1

T

CSD

H

0

H

1

χ

2

2M

H

0

χ

2

H

1

N r ˆ

y

r ˆ

yT

8

>>

<

>>

: TCSD

H1

∼ χ22M TCSD

H1

∼ χ22M NrˆxxT

!

(47)

p

f a

p

d

H

0

H

1

p

CSDf a

= Γ(λ/2, M ) p

CSDd

= Q

M

p λ, q

N r ˆ

x

r ˆ

Tx

!

Γ(a, b) Q

M

(a, b)

Γ(a, b) = Z

b

0

t

a1

exp ( − t)dt Q

M

(a, b) = 1

a

M1

Z

+1

b

t

M

exp

− t

2

+ a

2

2

!

I

M1

(at)dt

I

M

(t) M

etc

(48)

{ β

i

}

i=1,...,m

; (m  N

s

) m ⇥ m C

yy

C

yy

= 2 6 6 6 6 6 4

E[y(n)y

(n)] E[y(n)y

(n − 1)] . . . E[y(n)y

(n − m)]

E[y(n − 1)y

(n)] E[y(n − 1)y

(n − 1)] . . . E[y(n − 1)y

(n)]

. . .

E[y(n − m)y

(n)] . . . E[y(n − )y

(n − 1)] . . . E[y(n − m)y

(n − m)]

3 7 7 7 7 7 5

C

yy

H

0

C

yy

β

1

= β

2

= ... = β

m

= σ

w2

H

1

s(n) w(n) C

yy

C

ss

C

ww

s(n) w(n)

β

1

= β

1s

+ σ

w2

β

2

= β

2s

+ σ

w2

. . .

β

m

= β

ms

+ σ

2w

β

1s

≥ β

2s

... ≥ β

sm

β

max

β

min

C

yy

β

max

min

T

ED

min

β

min

(49)

C

yy

w(n) || w(n) ||

2

χ

2

χ

2

χ

2

T

GoF

T

GoF

= − X

N n=1

✓ ln(F

0

(y(n)))

N − n + 1/2 + ln(1 − F

0

(y(n))) n − 1/2

F

0

χ

2

T

GoF

(50)

p

d

p

f a

p

d

p

f a

p

d

p

f a

p

d

p

f a

N

s

= 4

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

pfa

p d

SNR=12 dB, N=1000 samples

ED CSD ACD

p

d

p

f a

= 0.1 N

s

= 8 N = 1000

p

d

p

f a

N

s

(51)

18 16 14 12 10 8 6 0.1

0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

SNR (dB)

p d

pfa=0.1; N=1000 samples

ED CSD ACD

i.e. p

d

, p

f a

N

(p

f a

= 0.1, p

d

= 0.9)

N

s

= 3 N

(52)

102 103 104 105

25

20

15

10

5 0

SNR (dB)

Number of samples (pfa ; p

d) = (0.1 ; 0.9); N s=3 sps

ED CSD ACD

(pf a;pd) = (0.1; 09)

C

ED

N | y(n) |

2

N − 1

| y(n) |

2

2N − 1

C

ED

= 2N − 1

C

CSD

= (N

s

− 1)N (L + 1) + 4(N

s

− 1)L

2

+ 8(N

s

− 1)

3

+ 6(N

s

− 1)

2

+ 2(N

s

− 1))

c

m

= 1 2N − 1

ˆ

r

yy

(m)

(53)

N

s

N

s

− 1 m = 1, ..., N

s

− 1

C

ACD

= (N

s

− 1)(2N − 1) + N

s

− 2

= 2(N

s

− 1)N − 1

(p

f a

= 0.1; p

d

= 0.9)

-18 -16 -14 -12 -10 -8 -6

SNR (dB) 102

103 104 105 106 107 108

Number of required operations

(pfa ; p

d) = (0.1 ; 0.9); N s=3 sps

ED CSD ACD

(pf a;pd) = (0.1; 09)

etc

(54)

ˆ σ

2w

ˆ σ

w2

2

 1

κ σ

2w

; κσ

w2

7

σ

w2

κ κ ≥ 1

ˆ σ

w2

f

σˆ2

w

( ˆ σ

2w

)

fεˆ(ˆε) = 8

><

>: 1

2ρ, ε−ρ≤εˆ≤ε+ρ 0, elsewhere

ε = 10 log

10

w2

) ˆ ε = 10 log

10

(ˆ σ

2w

) ρ = 10 log

10

(κ)

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

pfa 0

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

pd

SNR=-10 dB, N=1200 samples

ED: ρ = - 0 dB CSD: ρ = - 0 dB ACD: ρ = - 0dB ED: ρ = - 0.75 dB CSD: ρ = - 0.75 dB ACD: ρ = - 0.75 dB ED: ρ = - 2 dB CSD: ρ = - 2 dB ACD: ρ = - 2dB

ρ

p

f a

(p

f a

< 0.5; p

d

> 0.5) (κ − 1/κ)

N

s

= 2 ρ = 0

N

s

(55)

2N − 1

(2(N

s

− 1)N )

(N

s

− 1)N (L + 1) + 4(N

s

− 1)L

2

+ 8(N

s

− 1)

3

+ 6(N

s

− 1)

2

+ 2(N

s

− 1))

!

etc

(56)

N = 1000

N

a

= 5

(57)

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 0

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

p

p d

N=1000 samples, SNR=10 dB, Rayleigh Channel

Local SCS OR AND

Majority: 3 out of 5

N

sig

N

a

N

sig

 N

a

(58)
(59)
(60)

N

a

H

η

: y

i

(n) = ηh

i

s(n) + w

i

(n)

η 2 { 0; 1 } H

0

H

1

y

i

(n) 1 ⇥ N ith

N s(n) w

i

(n)

ith

σ

w2i

h

i

ith

(61)

(n) (n)

=

1 1

= Cov[ (n), (n)] C ˆ

ˆ = 1

N X

N n=1

(n)

H

(n)

H

(n) (n)

(n) (n)

(n) = [z

1

(n), z

2

(n), ..., z

Na1

(n)]

T

(n) = [y

1

(n), y

2

(n), ..., y

Na2

(n)]

T

y

i

(n) z

i

(n) ith

N

a1

N

a2

N

a

N

a1

N

a2

N

a

(n) (n)

(n, m, α) = (n − m) exp (j2παn) α

s(n) m P

N

n=1

s(n)s

(n − m)e

j2παn

α s

(n) s(n)

(62)

α

ˆ

ˆ = 1

N X

N n=1

(n)

H

(n, m, α) 1

N X

N n=1

(n)

H

(n − m) exp ( − j2παn)

ˆ ˆ

H

ˆ

α ˆ N

ˆ = 1

N X

N n=1

(n − m) exp (j2παn)

H

(n − m) exp ( − j2παn)

= 1 N

X

N n=1

(n − m)

H

(n − m)

ˆ

ˆ = ˆ

1

ˆ ˆ

1

ˆ

H

N

a

= 1 ˆ =

N1

P

N

n=1

y

1

(n)y

1

(n − m) exp ( − j2παn) = ˆ R

y1y1

(α, m) y

1

(n)

ˆ =

N1

P

N

n=1

| y

1

(n − m) |

2

' R ˆ

y1y1

(0, 0) N R ˆ

y1y1

(0, 0) =

1 N

P

N

n=1

| y

1

(n) |

2

y

1

(n) z

1

(n) = y

1

(n −

m) exp (j2παn)

ˆ = ˆ R

y11y1

(0, 0) ˆ R

y1y1

(α, m) ˆ R

y11y1

(0, 0) ˆ R

y1y1

(α, m))

= 1

| R ˆ

y1y1

(0, 0) |

2

| R ˆ

y1y1

(α, m) |

2

N

a

> 1 ˆ

ˆ =

2 6 6 6 6 6 4

R ˆ

y1y1

(α, m) R ˆ

y1y2

(α, m) . . . R ˆ

y1yNa

(α, m) R ˆ

y2y1

(α, m) R ˆ

y2y2

(α, m) . . . R ˆ

y2yNa

(α, m)

. . .

R ˆ

yNay1

(α, m) . . . R ˆ

yNay2

(α, m) . . . R ˆ

yNayNa

(α, m)

3

7 7

7 7

7 5

(63)

ˆ

T

CCST

= − N log

Na

Y

i=1

(1 − β

i

)

!

{ β

i

} , 1  i  N

a

ˆ 1 ≥ β

1

≥ β

2

≥ ...β

Na

≥ 0 i.e.β

i

 1

ˆ

1

ˆ

1

ˆ

H

0

N

a

ˆ ' β

1

= β

2

, ..., β

Na

= 0 T

CCST

H

1

ˆ s(n)

T

CCST

T

CCST

ˆ T

CCST

(n)

H

0

H

1

H

0

H

1

8

<

:

H

0

: y

1

(n) = w

1

(n)

H

1

: y

1

(n) = h

1

s(n) + w

1

(n)

(64)

V

V = [m

1

, m

2

, ..., m

P

] P

P

N

n=1

s(n − m

p

)s

(n − m

k

)e

j2παn

6 = 0 8 m

p

, m

k

2 V

1

(n, [m

1

; m

k

])

1

(n, [m

1

; m

k1

]) = h

y

1

(n − m

1

), y

1

(n − m

2

), ... y

1

(n − m

k1

) i

T

1 < k

1

 P

1

(n, [m

1

; m

k1

])

1

(n, [m

1

; m

k2

], α)

1

(n, [m

1

; m

k2

], α) =

1

(n, [m

1

; m

k2

]) exp (j2παn), 8 k

1

, k

2

2 [1; P ]

min (k

1

; k

2

) > l l

k

1

≥ k

2

> 1

1

(n, [m

1

; m

k1

])

1

(n, [m

1

; m

k2

], α) y

1

(n)

y(n)

R ˆ

SAS

ˆ

SAS

= ˆ

1 11

ˆ

1 1

ˆ

1

1 1

ˆ

1 1

ˆ

1 1

ˆ

1 1

ˆ

1 1

ˆ

1 1

ˆ

1 1

ˆ

1 1

H

0

ˆ

0

1 1

ˆ

0

1 1

= 2 6 6 6 6 6 4

R ˆ

ww

(α, [m

1

; m

1

]) R ˆ

ww

(α, [m

1

; m

2

]) . . . R ˆ

ww

(α, [m

1

; m

k2

]) R ˆ

ww

(α, [m

2

; m

1

]) R ˆ

ww

(α, [m

2

; m

2

]) . . . R ˆ

ww

(α, [m

2

; m

k2

])

. . .

R ˆ

ww

(α, [m

k1

, m

1

]) . . . R ˆ

ww

(α, [m

k1

; m

2

]) . . . R ˆ

ww

(α, [m

k1

; m

k2

])

3

7 7

7 7

7 5

(65)

R ˆ

ww

(α, [m

i

; m

j

])

R ˆ

ww

(α, [m

i

; m

j

]) = 1 N

X

N n=1

w

1

(n − m

i

)w

1

(n − m

j

)e

j2παn

w

1

(n) α 6 = 0 ˆ

0

1 1

'

1

(n, [m

1

; m

k2

])

1

(n, [m

1

; m

k2

], α)

H

1

ˆ

1

1 1

ˆ

1

1 1

(α) = ˆ R

ss

(α) + ˆ R

sw

(α) + ˆ R

ws

(α) + ˆ R

0rq

(α) R ˆ

ws

(α) R ˆ

sw

(α)

R ˆ

ss

(α)

R ˆ

ss

(α) = | h |

2

2 6 6 6 6 6 4

R ˆ

ss

(α, [m

1

; m

1

]) R ˆ

ss

(α, [, [m

1

; m

2

]) . . . R ˆ

ss

(α, [m

1

; m

k2

]) R ˆ

ss

(α, [m

2

; m

1

]) R ˆ

ss

(α, [m

2

; m

2

]) . . . R ˆ

ss

(α, [m

2

; m

k2

])

. . .

R ˆ

ss

(α, [m

k1

, m

1

]) . . . R ˆ

ss

(α, [m

k1

; m

2

]) . . . R ˆ

ss

(α, [m

k1

; m

k2

]) 3 7 7 7 7 7 5

R ˆ

ss

(α, [m

i

; m

j

]) s(n) m

i

m

j

R

ss

(α)

s(n) α

α

T

SAS

T

SAS

= − N log

k1

Y

i=1

(1 − β

is

) { β

is

} , i = 1, 2, ..., N

a

1 ≥ β

s1

≥ β

2s

≥ ... ≥ β

Nsa

l l

(66)

l = 1 T

SAS

T

SAS

= − N log(1 − β

1s

)

T

SAS

λ

T

SAS

H1

R

H0

λ

T

SAS

R ˆ

SAS

R ˆ

SAS

T

SAS

T

SAS

λ

(n, m) (n, p, α)

(n, [m

1

; m

k1

]) = [

1

(n, [m

1

; m

k1

]),

2

(n, [m

1

; m

k1

]), ...,

Na

(n, [m

1

; m

k1

])]

T

(n, [m

1

; m

k2

], α) = [

1

(n, [m

1

; m

k2

], α),

2

(n, [m

1

; m

k2

], α), ...,

Na

(n, [m

1

; m

k2

], α)]

T

i

(n, [m

1

; m

k2

]), 1  i  N

a

ith

i

(n, [m

1

; m

k2

], α) =

i

(n, [m

1

; m

k2

])e

j2παn

1  i  N

a

α (n, [m

1

; m

k1

]) (n, [m

1

; m

k2

], α)

ˆ

M AS

= ˆ

1

ˆ ˆ

1

ˆ

(67)

T

M AS

= − N log(1 − β

1m

)

β

1m

ˆ

M AS

(n, [0; 0]) (n, [m

1

; m

1

], α)

1µs F

s

i.e. F

s

= 8B B

ith

V

sim

= [0, T

s

, 2T

s

, 3T

s

, 4T

s

, 5T

s

, 6T

s

, 7T

s

] T

s

=

F1

s

1

(n, [m

1

; m

k1

])

k

1

= 8 k

2 1

(n, [m

1

; m

k2

], α)

i.e. V

sim

p

d

p

f a

k

2

(68)

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 0

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

Pf

p d

SNR=−10 dB, N=2000 samples

CCST−S:p2=1 CCST−S: p2=5 CCST−S: p2=8 GLRT

-8-8-8

pfa

p

f a

V

sim 1

(n, [m

1

; m

k1

])

1

(n, [m

1

; m

k2

], α) i.e. k

1

= k

2

= p p

f a

= 0.1

p

d

(n, [m

1

; m

k1

]) (n, [m

1

; m

k2

], α)

V

sim

(69)

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 pfa

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

p d

SNR=-8 dB, N=1500 samples

CCST-S, NU=0 dB ED, NU=0 dB CCST-S, NU=0.5 dB ED, NU=0.5 dB CCST-S, NU=1.5 dB ED, NU=1.5 dB

−10 −8 −6 −4 −2 0 2 4

0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

SNR (dB)

p d

pfa=0.1, N=1000 samples

p=2 p=4 p=6 p=8

pf a= 0.1

(70)

2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 103

10−2 101 100

Number of SU receiving antennas: M

p md

pfa=0.1; N=2000 samples, SNR=−10 dB

CCST−M CCST−D

pmd= 1−pd

pf a = 0.1

p

md

N

a

N = 1000 − 10 p

f a

= 0.1

N

a

p

md

N

a

N

a

= 5 p

md

' 0.2 p

md

' 0.06 N

a

= 7

p

md

0.1 p

md

= 0.004

E[w

i

(n)w

j

(n)] = 8

<

:

σ

w2

i = j σ

w2

γ

|ij|

i 6 = j

; 1  i, j  M ;

γ 0  γ  1

(71)

−16 −14 −12 −10 −8 −6 −4 103

10−2 10−1 100

pfa=0.05; M=5; N=1000 samples

SNR (dB)

p md

CCST−M CCST−D

pmd= 1−pd

pf a = 0.05

N

a

= 5 N = 1000

p

md

= 0.5 = − 14dB = − 12dB

N

a

− 12 N

a

= 6 N = 2000

p

md

= 0.1 p

f a

= 0.03

p

md

p

f a

= 0.5

(72)

103 102 101 100 10−4

103 10−2 10−1 100

p md

pfa

SNR=−12 dB, M=6; N=2000 samples

CCST−D CCST−M

pmd= 1−pd

pf a = 0.05

(73)
(74)

i.e. N

s

≥ 2

N

s

= 2

N

s

= 2

(75)

s(n) B

s(n) s

p

(n) s

q

(n)

s(n) s(n) = X

k

b

k

g(n − k + N

s

) = s

p

(n) + js

q

(n)

b

k

g(n) N

s

N

s

=

FBs

≥ 2 F

s

s

p

(n) s

q

(n) s(n)

H

0

H

1

8

<

:

H

0

: y(n) = w(n)

H

1

: y(n) = hs(n) + w(n)

h w(n)

σ

w2

N (0, σ

w2

) w(n) = w

p

(n) + jw

q

(n) i.i.d i.e. E[w

2

(n)] = 0 w

p

(n) w

q

(n) w(n)

E[w

2p

(n)] = E[w

2q

(n)] = σ

w2

2 σ

w2

= E[ | w(n) |

2

] E[.]

s(n) γ

γ = | h |

2

σ

w2

(76)

P

x

(k) x(n) r

xx

(m)

r

xx

(m) = E[x(n)x

(n − m)]

P

x

(k) = lim

N!+1

N

X

2

m=N21

r

xx

(m) exp ( − j2πk m N )

w(n) w(n)

r

ww

(m) = E[w(n)w

(n − m)] = σ

w2

δ(m)

δ(m)

P

w

(k) = σ

2w

σ

w2

s(n) P

s

(k)

(y(n))

x(n)

P ˆ

x

(k) = 1

N | X(k) |

2

X(k) x(n) N

X(k) =

N

X

2

n=N21

x(n) exp ⇣

− j2πk n N

(77)

Lemma 1 X(k) x(n) = x

p

(n) + jx

q

(n)

X(k) E[X

2

(k)] = 0

X(k) x(n)

E[X

2

(k)] = E 2 6 4

X

N

m,n=N21

x(n) exp ⇣

− j2πk n N

x(m) exp ⇣

− j2πk m N

⌘ 3 7 5

=

X

N m=n=N21

E[x

2

(n)] exp

− j2πk 2n N

| {z }

=0;using the circularity property of x(n)

+ X

N m6=n

E [x(n)x(m)] exp

− j2πk n + m N

| {z }

= 0as x(n)is i.i.d. and zero mean

= 0

Lemma 1 W (k) w(n)

CP

y

(k) y(n)

CP

y

(k) = X

k u=v

P ˆ

y

(u), , 8 k 2 [v; l],

P ˆ

y

(u) y(n)

Ψ(k) y(n)

Ψ(k) = CP

y

(k)

(l − v + 1)σ

w2

Références

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