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Full Text - Journal of Theoretical and Applied Information Technology

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<strong>Journal</strong> <strong>of</strong> <strong>Theoretical</strong> <strong>and</strong> <strong>Applied</strong> <strong>Information</strong> <strong>Technology</strong><br />

10 th June 2013. Vol. 52 No.1<br />

© 2005 - 2013 JATIT & LLS. All rights reserved .<br />

ISSN: 1992-8645 www.jatit.org E-ISSN: 1817-3195<br />

was divided into M blocks zi(1), zi(2),..., z<br />

i( M ) ,<br />

The encoding function <strong>of</strong> the source (or relay) node<br />

was X ( ζ (1)) , X ( ζ (2)) ,…, X ( ζ ( M))<br />

.<br />

Si<br />

i<br />

Si<br />

i<br />

In the model <strong>of</strong> received signals above, the relay<br />

node R ( w≠ j)<br />

decoded the Code Book<br />

X<br />

Si<br />

w<br />

( ζ ( l))<br />

<strong>of</strong> l block.. When<br />

i<br />

ù g , the biggest<br />

2<br />

i<br />

< log(1 + |<br />

ij<br />

| ⋅PS (<br />

i<br />

))<br />

misunderst<strong>and</strong>ing code probability would be so<br />

small. After obtaining the signal <strong>of</strong> Decode Block,<br />

the relay node sent the signal series<br />

0, X ( ζ (1)) , X ( ζ (2)) ,…, X ( ζ ( M))<br />

which<br />

Rw<br />

i<br />

Rw<br />

i<br />

was decoded in the next Block Slot. The transport<br />

method <strong>of</strong> block code signal was called Decode<br />

Relay. To the model architecture <strong>of</strong> System in this<br />

paper, the target (or relay) nodes used parallel<br />

decoding technology12.<br />

Supposed the destination (or relay) node had<br />

received the signal z ( k)<br />

<strong>of</strong> k block, <strong>and</strong><br />

i<br />

Meanwhile, the Code Book XS i<br />

( ζ<br />

i<br />

( k−<br />

2)) was<br />

decoded by the small misunderst<strong>and</strong>ing code<br />

probability, then the form <strong>of</strong> parallel decoding<br />

signal based on the model <strong>of</strong> received signals in the<br />

target (or relay) nodes was<br />

⎡<br />

⎣<br />

X ( ( ))<br />

S<br />

ζ<br />

i i<br />

k +<br />

∑<br />

w= 12 , ...m, w≠<br />

j<br />

Rw<br />

G (cosθ + isin θ ) X ( ζ ( k− 1)) + C ,<br />

X<br />

i<br />

Si<br />

jw jw Rw<br />

i j<br />

( ζ ( k − 1)) + C<br />

- ⎦<br />

(7)<br />

⎤<br />

Si<br />

i j 1<br />

If the source (or relay) node Si<br />

( i = 1,2,..., m)<br />

sent a code word that described the information<br />

received by the destination (or relay) node. Based<br />

on the discussion mentioned above, the relay node<br />

R ( w≠ j)<br />

would decode the information before<br />

R<br />

w<br />

j<br />

. So when the information was decoded<br />

successfully, every receiver node began to use<br />

another scheduled code word <strong>and</strong> sent the same<br />

information in the average power conditions.<br />

Supposed that the decoding time <strong>of</strong> the node R in<br />

a code block cycle was represented in the time slot<br />

t<br />

j<br />

. Then, t<br />

j<br />

means a period <strong>of</strong> a fading code block<br />

cycle when the node R j<br />

decoded <strong>and</strong> realied the<br />

information to the node Rw<br />

( w≠<br />

j)<br />

. According to<br />

the condition <strong>of</strong> right decoding, there was<br />

2<br />

ù log(1 + | g | ⋅ PS ( )) < 1 .<br />

i ij i<br />

i<br />

j<br />

Based on the actual physical channel <strong>and</strong><br />

decoding conditions, we supposed that the node R<br />

would neither decode nor send information when<br />

t ≥ 1.<br />

j<br />

Let p<br />

j<br />

to represent the probability which the<br />

node R<br />

j<br />

was decoded successfully. In addition, the<br />

mutual information related to node S<br />

i<br />

,<br />

R<br />

j<br />

was<br />

j<br />

2 2<br />

j<br />

= ∑( l<br />

−<br />

l −1)log(1 + | gij | ⋅ (<br />

i<br />

) + G ( −1))<br />

l = 1<br />

I t t PS l<br />

(8)<br />

In which t 0<br />

= 0 , by solving a equation I<br />

j<br />

= ù<br />

i<br />

, j = 1,2,..., n, we have:<br />

ù<br />

t =<br />

log(1 + | | ⋅PS<br />

( ))<br />

i<br />

1 2<br />

gi<br />

1<br />

2 2<br />

i2<br />

i<br />

ù<br />

i<br />

+ t1 log<br />

2<br />

1 + | gi2<br />

| ⋅PS<br />

(<br />

i)<br />

2<br />

=<br />

2 2<br />

log(1 + | gi2<br />

| ⋅ PS (<br />

i) + G )<br />

t<br />

t<br />

n<br />

=<br />

i<br />

1 + | g | ⋅ PS ( ) + G<br />

1 + | g | ⋅ PS ( ) + G<br />

ù<br />

i<br />

+ t<br />

+<br />

log(1 + | | ⋅ ( ) + ( −1) )<br />

2 2<br />

i2<br />

i<br />

1<br />

log<br />

2<br />

1 + | gi2<br />

| ⋅PS<br />

(<br />

i)<br />

2 2<br />

gin<br />

PSi<br />

n G<br />

2 2<br />

i3<br />

i<br />

2 2 2<br />

+ gi3<br />

⋅ PSi<br />

+ G<br />

2 2<br />

+ gin<br />

⋅ PSi<br />

+ n−<br />

G<br />

,…,<br />

1 + | g | ⋅ PS ( ) + 2G<br />

t log 1 | | ( )<br />

+ + ...<br />

log(1 | | ( ) ( 1) )<br />

t<br />

+<br />

1 + | g | ⋅ PS ( ) + ( n−1)<br />

G<br />

2 2<br />

in<br />

i<br />

n−1 log 1 | |<br />

2 ( ) ( 2)<br />

2<br />

+ gin<br />

⋅ PSi<br />

+ n−<br />

G<br />

2 2<br />

log(1 + | gin<br />

| ⋅ PS (<br />

i<br />

) + ( n−1) G )<br />

j<br />

,<br />

(9)<br />

( i = 1,2,..., m)<br />

Naturally, when t<br />

j<br />

< 1 <strong>and</strong> t<br />

j + 1<br />

≥ 1 , then p<br />

j<br />

> 0 ,<br />

p +<br />

= , ( j = 1,2,..., m)<br />

, <strong>and</strong> vice versa. So<br />

j 1<br />

0<br />

pj<br />

= Pr{ tj<br />

< 1}<br />

(10)<br />

Through the analysis (node decoding,<br />

cooperation <strong>and</strong> relay) mentioned above <strong>and</strong> the<br />

literature[15], in the sense <strong>of</strong> probability<br />

expectations, the throughput <strong>of</strong> mulit-hop relay<br />

sensor network based on cooperative diversity was<br />

expressed as<br />

6

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