energy-detection uwb receivers with multiplel energy measurements a.a.d’amico and u.mengali...

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Energy-Detection UWB Receivers with Multiplel Energy Measurements

A.A.D’Amico and U.MengaliDepartment of Information Engineering

University of PisaItaly

E. Arias-de-ReynaDepartment of SP and Communications

University of SevilleSpain

UWB4SN 2005, Lausanne



Outline

Conventional Energy-Detection (ED) Receiver

Comparisons with other schemes

Improved ED Receiver

Performance evaluation

Conclusions



Optimal decision strategy (1/2)

Assumptions Channel Response (CR) is unknown Perfect synchronization

Problem Joint estimation of CR and data symbols

aK-1=0

t

aK=1 a

K+1=1noise



x0

Solution

y0

a =k

0 if x0 0y>

1 if x0 0y<

t

noise

r (t)2

2.r(t) r (t)2



Conventional ED Receiver

“o”

UWBchannel

Tbsynch

Compare( )2.“1”

A.Rabbachin and I.Oppermann, UWBST, 2004

M.Weisenhorn and W.Hirt, UWBST, 2004

C.Carbonelli and U.Mengali, TWC 2005/06



Transmitted reference (TR)

-1

t

sT

+1+1

D



Differential transmitted reference (DTR)

-1

t

sT

-1+1



Performance comparisons

10-4

10-3

10-2

10-1

100

BER

17161514131211

Eb/N0 (dB)

CM1

CEDR TR DTR

ED/TR

DTR



Complexity comparisons

synch

Compare( )2. ED

D synch

TR/DTR



y0

x0

Small energy chips

a =k

0 if x0 0y>

1 if x0 0y<

t

r (t)2

y0

yN-1

x0

xN-1

a =k

0 if >xn yn

1 if <xn yn

t

r (t)2



Side information

Problem:

Given , what is the optimal decision strategy

based on the observation of and ?

s

x y

s0

sN-1

t

sx y

y0

yN-1

x0

xN-1

t

r (t)2



Optimal decision strategy

a =k

0 if >xn s n yn s n

1 if <xn s n yn s n

a =0, k

p( , | )syx p( , | )a =1, k

syx

a =1k

a =0k

Optimal

Approximation(energy correlation)



Improved ED receiver

“o”

UWBchannel

Tb

( )2.

synch

Compare

sk“1”



Performance (1/3)

10-4

10-3

10-2

10-1

100

BER

17161514131211

Eb/N0 (dB)

CM2

Δ=2 ns

CEDR EDRMM

conventional

improved

10-4

10-3

10-2

10-1

100

BER

17161514131211

Eb/N0 (dB)

CM1

Δ=2 ns

CEDR EDRMM

conventional

improved

2 dB2 dB



Performance (2/3)

10-4

10-3

10-2

10-1

100

BER

17161514131211

Eb/N0 (dB)

CM1

EDRMM

Δ → 0

Δ =8 ns

Δ =4 ns

Δ =2 ns

Δ =1 ns



Performance (3/3)

10-4

10-3

10-2

10-1

100

BER

17161514131211

Eb/N0 (dB)

CM1

Δ=2 ns

EDRMM

{em} estimated {em} known

estimatedsk

knownsk



Another approach (Weisenhorn and Hirt, ICUW, Sept. 2005)

Problem:

Given and the channel average power-delay

profile , which is the ML decision rule?

r(t)

(t)2

“o”

UWBchannel

Tb

( )2.

synch

Compare

w(t)“1”

A function of and (t) 2

0



Performance comparisons

10-4

10-3

10-2

10-1

100

BER

17161514131211

Eb/N0 (dB)

CM1

Δ=2 ns

CEDR WH EDRMM

WH method

Improved

10-4

10-3

10-2

10-1

100

BER

17161514131211

Eb/N0 (dB)

CM2

Δ=2 ns

CEDR WH EDRMM

Improved

WH methodEDED



Estimation of s (1/2)

sk

Tb

= E{ - }sk

xk

yk

k-th bins

xk

yk

Tb

noise



Estimation of s (2/2)

t

xk(N-1)x

k(1)x

k(0) y

k(0) y

k(1) y

k(N-1)

= E{ - }sk

xk

yks

k

^x

k(n) y

k(n)

-K=0

N-11N=



Conclusions

Pros: Improved performance over conventional ED

Automatic adaptation to channel statistics

Cons: Higher complexity (sampling rate)

energy-detection uwb receivers with multiplel energy measurements a.a.d’amico and u.mengali...

Documents

t s x y y

s x y s

y t r t

x n y n t r t

x n s n y n s n

y t noise r t

t b noise slide

solution y