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2
3
Definition 1. We say that a pair of vector-valued functions
Hx Hx
(), ()
L R C
( ,
v
)
are biorthogonal, if their translations satisfy
3
[( , (
HH n
⋅−=
]
δ
I
,
nZ
,
(2)
0 ,
nv
I denotes the vv
×
δ
where
is the Kronecker symbol.
Definition 2. A sequence of vector-valued functions
indentity matrix and
0 , n
2
3
v
is
{( }
Hx
⊂⊂
U LRC
(,
)
n
3
nZ
called a Riesz basis of U if itsatisfies (i) for any
Gx
()
U
, there exists a unique
2
3
vv
×
vv
×
{}
Q
( )
Z
matrix sequence
such that
n
s
nZ
3
Gx
()
=
QH x
(),
x R
,
(3)
nn
3
nZ
1
v
∑∑
2
3
vv
×
3
uu
×
2
()
Z
=
{:
Q
Z
→ =
C
,
Q
|
qn
( ) | )
<+∞
,
where
2
(ii) there
ls
,
2
4
ls
,
= ∈
1
nZ
0
<≤<+∞
CC
{}
n
M
exist two constants
such that, for any matrix sequence
,
1
2
3
nZ
the following equality follows.i.e.,
CM
{}||
MHx C M
( ||
{},
(4)
1
n
n
n
2
n
*
*
3
nZ
In what follows, we introduce the notion of vector- valued multiresolution analysis
and give the definition of biorthogonal vector-valued wavelets of space
v
LR C .
2
3
(,
)
Definition 3. A vector-valued multiresolution analysis of the space
v
LR C is a
2
3
(,
)
nested sequence of closed subspaces {} Z
Y
YY
⊂∀∈
1 ,
Z
;
such that (i)
(ii)
ℓℓ
Y
=
{0}
Z Y
and
is dense in
v
LR C , where 0 denotes an zero vector of
2
3
(,
)
Z
v
R
;
Φ∈⇔Φ
( xY
(
Mx
)
∈∀∈
Y
,
Z
space
(iii)
; (iv) there exists
1
Fx
()
Y
,called a vector-valued scaling function, such that its translates
0
3
nZ
n Fx
():
=−
Fx n
(
),
Y
0 .
forms a Riesz basis of subspace
Fx
()
∈⊂
Y
Y
, by Definition 3 and (4) there exists a finitely supported se-
quence of constant vv
Since
0
1
×
matrice
such that
{}
Ω
2
(
Z
3
vv
×
n
3
nZ
(5)
Fx
()
FMx n
(
).
n
3
nZ
Equation (6) is called a refinement equation. Define
3
()
γ
=
exp{
− ⋅
in
γ
},
γ
R
.
m
Ω
Ω
(6)
n
3
nZ
s
, which is 2
π
Z
Fx . Thus, (6) becomes
3
()
where ( )
Ω
γ
fun., is called a symbol of
ˆ
ˆ
FM
(
γ
)
() (),
γ
F
γ
γ
R
. (7)
Xj Z
Y in
Y +
1 .
Let
be the direct complementary subspace of
Assume that
,
ψ
()
xLRC
23
( ,
v
),
μ
∈Γ
there exist 63 vector-valued functions
such that their
μ
X
tran- slations and dilations form a Riesz basis of
i.e.,
j
,
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