Information Technology Reference
In-Depth Information
3D gnof2
T
-Periodic
M
-Ary LCZ Sequence Sets
The interleaved technique [2] may be applied to construct nT -periodic sequences
with low correlation from a T -periodic sequence with good autocorrelation,
where both n and T are positive integers. The technique may also be used to
construct 2 T -periodic M -ary LCZ sequences from a T -periodic M -ary sequence
with good autocorrelation.
Let
{
s ( t )
}
be a T -periodic M -ary sequence satisfying
|
C s ( τ )
|≤
T− 2 .
for some nonnegative constant . Assume that M is even and 1
d
Let
2 T− 1
4 d if d
T−
1
2
f =
(1)
2 T− 3
4 d if d
T− 1
2
|
.
The set
IS
of 2 T -periodic sequences is defined as
IS
=
{{
s ( i,m ) ( t )
}|
0
i
f
1 ,m =0 , 1
}
(2)
where
s ( i, 0) (2 t )= s ( t
id ) ,s ( i, 0) (2 t +1)= s ( t +1+( i +1) d ) ,
id )+ M
2
s ( i, 1) (2 t )= s ( t
,s ( i, 1) (2 t +1)= s ( t +1+( i +1) d )
T−
1
for d
,and
2
s ( i, 0) (2 t )= s ( t
id ) ,s ( i, 0) (2 t +1)= s ( t +2+( i +1) d ) ,
id )+ M
2
s ( i, 1) (2 t )= s ( t
,s ( i, 1) (2 t +1)= s ( t +2+( i +1) d )
T− 1
2
for d
contains 2 fM -ary sequences of period 2 T .The
crosscorrelation between any two sequences in
|
. Note that the set
IS
IS
is derived in the following
lemma.
Lemma 1. Let τ =2 τ 1 + τ 0 , τ 0 ∈{
0 , 1
}
,and 0
τ 1
T
1 .For 0
i, j
f
1 , m, n
∈{
0 , 1
}
,let a = j
i and b = j + i +1 . Then the crosscorrelation
C ( i,m ) , ( j,n ) ( τ ) between
{
s ( i,m ) ( t )
}
and
{
s ( j,n ) ( t )
}
is given as follows:
1
2 :
C ( i, 0) , ( j, 0) ( τ )= C s ( τ 1 + ad )+ C s ( τ 1
T
Case i) d
ad ) ,
if τ 0 =0;
C s ( τ 1 + bd +1)+ C s ( τ 1
bd ) , if τ 0 =1;
C ( i, 1) , ( j, 1) ( τ )= C s ( τ 1 + ad )+ C s ( τ 1
ad ) ,
if τ 0 =0;
bd ) , if τ 0 =1;
C ( i, 0) , ( j, 1) ( τ )= −C s ( τ 1 + ad )+ C s ( τ 1 − ad ) , if τ 0 =0;
C s ( τ 1 + bd +1)
C s ( τ 1
C s ( τ 1 + bd +1) − C s ( τ 1 − bd ) , if τ 0 =1;
C ( i, 1) , ( j, 0) ( τ )=
C s ( τ 1 + ad )+ C s ( τ 1
ad ) ,
if τ 0 =0;
C s ( τ 1 + bd +1)+ C s ( τ 1
bd ) , if τ 0 =1;
Search WWH ::




Custom Search