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Journal of Engineering Technology Volume 6, Special Issue on Technology Innovations and Applications
Oct. 2017, PP. 392-404
392
A note on the singular value decomposition of inverse-orthogonal circulant
jacket matrices
K. M. Cho1
, Md. Abdul Latif Sarker1
, N. Yankov2
, Moon Ho Lee1*.
1Department of Electronics and Information Engineering, Conbuk National University, Jeonju-si, 54896 Korea.
2The Faculty of Mathematics and Informatics, Shumen University, Shumen 9712, Bulgaria.
*Corresponding author: Moon Ho Lee
Abstract. This study investigates the singular value decomposition (SVD) of inverse orthogonal circulant
Jacket (CJ) matrices, which are able to be constructed by inverse orthogonal Toeplitz matrices. These CJ
matrices are applied to a variety of fields of engineering and mathematical disciplines such as signal
processing, wireless communications, and so forth. The SVD of inverse orthogonal CJ matrices is enabled to
compute small, medium, and large size matrices with higher accuracy.
Keywords: Toeplitz and Jacket matrices, Circulant Jacket (CJ) matrices, Eigen value decomposition
(EVD), Singular value decomposition (SVD).
1. Introduction
The matrices such as Toeplitz [1], circulant [1, 2, 3], Hadamard [4], and Jacket matrices [5, 6, 7], have an
important role in numerical analysis and signal processing. The practical values of Hadamard transformation
such as center weighted Hadamard transformation represent their corresponding signals and images. The class
of Jacket matrices also contains the class of real and complex Hadamard matrices. Jacket matrices generated
by inverse orthogonal Toeplitz matrices are in fact circulant Jacket (CJ) matrices. We present a very simple
decomposition of CJ matrices which can provide efficient eigenvalue and singular-value decomposition
strategies in this paper. These eigenvalue and singular-value decomposition techniques are extensively used in
signal processing and wireless communications which are broadly used in practice thanks to their efficiently
computable inverse matrices. The Jacket matrices are a generalization of complex Hadamard matrices. A
square n × n matrix ( )ijM m is called a Jacket matrix [5] if its inverse satisfies-1
,
,
]1
[ i j
j i
Mnm
, i.e., the inverse
matrix can be obtained by taking element-wise inverse and transpose, up to a negligible constant factor.
Equivalently, these matrices satisfy the following relations:
,
,
1 ,
, , 1, , ,n
i k
i j
k j k
mn i j n
m
(1)
where ,i j is the Kronecker delta - a function of two variables, usually integers,
0, if .
1, if ij
i j
i j
(2)
Journal of Engineering Technology Volume 6, Special Issue on Technology Innovations and Applications
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If C is nonzero constant, then the definition of Jacket matrix can be rewritten as follows. A square m × m
matrix
0,0 0,1 0, 1
1,0 1,1 1, 1
1,0 11 1, 1
m
m
m
m m m m
j j j
j j jJ
j j j
is called a Jacket matrix if its normalized element-wise inverse and transpose
0,0 0,1 0, 1
1,0 1,1 1, 1
1,0 11 1, 1
1/ 1/ 1/
1/ 1/ 1/1
1/ 1/ 1/
T
m
m
m
m m m m
j j j
j j jJ
C
j j j
satisfies .m m mJ J I
A Jacket matrix in which the modulus of each entry is unity, is called a complex Hadamard matrix [4]. It is
easy to see that if K is a jacket matrix, then for every permutation matrices 1 2,P P , and for every invertible
diagonal matrix 1 2,D D , the matrix
1 1 2 2H PD KD P is a Jacket matrix as well. Jacket matrices related in this
fashion are called equivalent. Finding all jacket matrices up to equivalent ones turns out to be a challenging
problem, and has been solved only up to orders 5n [8].
The property of Jacket matrices is, that for any two different rows ,1 ,, ,i i na a and ,1 ,, ,j j na a , it is
necessary to have the Jacket condition
,
1 ,
0.n
i s
s j s
a
a
(3)
Requirement of Eq. (1) instead of usual inner product is given as bad algebraic properties, about Jacket
matrices - for example, multiplication of two Jacket matrices in general is not a Jacket matrix. However,
Jacket matrices have some interesting combinatorial properties. For example, if we multiply some rows or
columns by any non-zero element, then the resulting matrix remains a Jacket matrix. This type of equivalence
operation splits the space in large classes of matrices. In an orthogonal case, we can multiply only by 1 . We
conclude this section with some examples of Jacket matrices. Examples of Jacket matrices are the following
matrices of order 2n and 3, respectively:
2
1 1,
1 1A
2
3
2
1 1 1
1
1
A
,
where 2 1 0 , i.e., 1 3
,2 2
so alternative notation is
3
1 1 1
1 3 1 31 .
2 2 2 2
1 3 1 31
2 2 2 2
A
Numerous examples can be found in [6]. Some of the Jacket matrices can have parameters. For example, for
every nonzero a, the following matrix
Journal of Engineering Technology Volume 6, Special Issue on Technology Innovations and Applications
Oct. 2017, PP. 389-402
394
4
1 1 1 1
1 1
1 1
1 1 1 1
a aA
a a
,
is not only a Jacket matrix but also a symmetric matrix. Also, it is easy to check that the Vandermonde matrix
of n-th roots of unity1, , nx x ,
1 2
2 2 2
1 2
1 1 1
1 2
1 1 1
n
n
n n n
n
x x x
W x x x
x x x
,
is a Jacket matrix, too [7].
This paper is organized as follows. First, we investigate the system model in Section 2. In Section 3, we show
the relation between the circulant and inverse orthogonal circulant Jacket (CJ) matrices. In Section 4, we
calculate the eigenvector and eigenvalues of inverse CJ matrices. In Section 5, we compute the SVD of
inverse CJ matrices, which can be applied to wireless MIMO communications shown in Section 6. Finally, the
conclusions are drawn in Section 7.
2. System Model
A Toeplitz matrix is an n × n matrix such that ,{ ; , 0,1, , 1},n k jT t k j n where
,k j k jt t for some elements
1 1 0 1 1, , , , , ,n nt t t t t . In other words, the Toeplitz matrixes have diagonal-constant elements and have
the form
0 1 2 1
1 0 1
2 1
1 2
1 0 1
1 2 1 0
.
n
n
n
t t t t
t t t
t tT
t t
t t t
t t t t
(4)
Such matrices have been found in many applications. For example, suppose that 0 1 1( , , , )T
nx x x x is a column
vector denoting an “input” and that kt is zero for 0k . Then the vector,
y x znT (5)
with entries 1
0
k
k k i i
i
y t x
represents the output of the discrete time causal time-invariant filter h with
“impulse response” .kt Equivalently, this is a matrix and vector formulation of a discrete-time convolution of
a discrete time input with a discrete time filter.
As another example, suppose that { }nX is a discrete time random process with mean function given by the
expectations ( )k km E X and covariance function given by the expectations ( , ) [( )( )].X k k j jK k j E X m X m
The signal processing theory such as prediction, estimation, detection, classification, regression, and
Journal of Engineering Technology Volume 6, Special Issue on Technology Innovations and Applications
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communications, and information theory are most thoroughly developed under the assumption that the mean
is constant and that the covariance is Toeplitz, i.e., ( , ) ( ),X XK k j K k j in which case the process is said to
be weakly stationary. (The terms “covariance stationary” and “second order stationary” also are used when the
covariance is assumed to be Toeplitz.) In this case, the n × n covariance matrices
[ ( , ); , 0,1, , 1]n XK K k j k j n are Toeplitz matrices. Many theories of weakly stationary processes involve
applications of Toeplitz matrices. Toeplitz matrices also give a hand with solutions to differential and integral
equations, spline functions, problems, and methods in physics, mathematics, statistics, and signal processing.
3. Circulant and Inverse Orthogonal Circulant Jacket Matrices
A common special case of Toeplitz matrices – which will result in significant simplification and play a
fundamental role in developing more general results when every row of the matrix is a right cyclic shift of the
row above it so that ( )k n k k nt t t for 1,2, , 1.k n In this case, the resulting matrix becomes,
0 1 2 1
1 0 1 2
1 0
2 1
1 2 1 0
.
n
n
n
n n
n n
c c c c
c c c c
C c c
c c
c c c c
(6)
A matrix of this form is called a circulant matrix and usually is denoted by 0 1 1circ( , , , ).nc c c
Circulant
matrices have been made good use of in various engineering areas such as the discrete Fourier transform
(DFT) and cyclic codes for error correction.
In [9], there is an example of inverse-orthogonal Toeplitz or Toeplitz Jacket (TJ) matrices of order 4
24
2 2
2
( , , ) .
bca b c
a
aba b c
cTJ a b c
a aba b
c c
a b a aba
c cc
(7)
We take advantage of the diagonal matrices that can be used to replace the matrix with the circulant Jacket
matrix. One interesting thing about the aforementioned matrix has three independent parameters which are
one more than those of circulant matrices with the same size. This extra parameter, however, is giving rise due
to the following non-trivial symmetry of Toeplitz matrices. We use the notation 1 2, ,..., nDiag a a a to refer to the
n × n diagonal matrix with diagonal entries ai, i=1,2,…,n. Therefore, a square n × n inverse-orthogonal
Toeplitz matrix is called a CJ matrix where ai is an arbitrary complex number and b is a nonzero complex
number. Then, we arrive at Lemma 1 as follows:
Lemma 1. Let nT be a Toeplitz matrix of order n, and let a be an arbitrary complex number while let b be
a nonzero complex number. Then, the following matrix is a Toeplitz matrix as well:
' 1 2 1 2 11, , , . . . , 1, , , . . . , n n
n nT aDiag b b b T Diag b b b . (8)
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Proof: It is easy to see that the (i, j)-th entry of 'nT leads to
j iijt ab
in [9].
Now we show a structural result w.r.t. Toeplitz-Jacket matrices
Proposition 1. Suppose that T is a Toeplitz Jacket matrix. Then, with the notations from Eq. (4), we have
1
1
, 1,2,... 1ll n l
n l
tt t l n
t
(9)
Proof: Note that the Eq. (9) holds trivially for 1l . We begin the proof by showing that it holds for 2l .
We assume that 3n .
Considering the Eq. (3) within the first two rows of nT , i.e., for , 2,1i j , we reach
0 21
0 1 1
0n
n
t tt
t t t
(10)
Next, the Eq. (3) for the pair of rows , 3,2i j results in
0 32 1
1 0 1 2
0n
n
t tt t
t t t t
Adding 2
1
n
n
t
t
to both sides and by means of Eq. (10), it is easy to prove that the Eq. (9) holds for 2l . In
addition, when 1l , we get to
1 1 , 1,2,... 2l n l
l n l
t tl n
t t
(11)
Now, by using mathematical induction, we prove that the Eq. (11) holds for all 1 2l n . We can assume
that 4n because it was already proven that the Eq. (11) holds for 3l n . Then, we consider the Eq. (3)
for the pair of rows 3, 2l l :
12
10
0
nl k
l kk
t
t
,
and rewrite it using the Eq. (11) as
12 2
1 10
0
nl n k
l n kk
t t
t t
.
Adding 2 1/n l n lt t to both sides and by means of Eq. (10), it is easy to prove that the Eq. (11) holds for
1.l l We complete the proof by using the Eq. (10) for the consecutive terms lt and 1lt , hence
1 11 1
n l l n l ll l n l n l
n l n l n l n l
t t t tt t t t
t t t t
.
Now, we move to Theorem 1 about a Toeplitz-Jacket n
TJ and a circulant-Jacket n
CJ matrix.
Theorem 1. Every Toeplitz-Jacket matrix is equivalent to a circulant-Jacket matrix.
Proof Theorem 1. Let n
TJ be a Toeplitz-Jacket matrix as in the Eq. (4) and assume1 1/n
nx t t , where the
operator n denotes the principal n th root. By Lemma 1, the matrix
Journal of Engineering Technology Volume 6, Special Issue on Technology Innovations and Applications
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1 1 1 11 1n n
n nCJ diag x x TJ diag x x (12)
is a Toeplitz matrix equivalent to n
TJ . This n
CJ is called a circulant-Jacket matrix. To see this, it is
enough to show that 1, 2,1j n jc c for every 2,...,j n . It is clear that
11, 1
jj jc t x
. On the other hand, by
using Proposition 1, we have,
1 1 112,1 1 1 1
1
n j n j jn j n j j j
n
tc t x t x t x
t
.
Using the Eq. (7) in the Eq. (12), if a=b=c=1, and n=4, then the [CJ]4 is given by
0 1
41 0
1 1 1 1
1 1 1 1
1 1 1 1
1 1 1 1
C CCJ
C C
. (13)
Proposition 2. Let 0 1
1 0n
C CCJ
C C
be a 2×2 block matrix of order n=2p. If [C0]p and [C1]p are p×p
Jacket matrices, then [CJ]n is a block circulant Jacket matrix if and only if
0 1 1 0 0RT RT
nC C C C , where RT is the reciprocal transpose. (14)
Proof. Since 0C and 1C are Jacket matrices, we have 0 0
RT
pC C p I and 1 1
RT
pC C p I . Note that [CJ]n is a
block circulant Jacket matrix if and only if RT
nn nCJ CJ nI . Then, [CJ]n is a Jacket matrix if and only if
0 1 1 00 1 0 1
1 0 1 0 0 1 1 0
2
2
RT RTRTpRT
n n nRT RT
p
p I C C C CC C C CCJ CJ n I
C C C C C C C C p I
(15)
Hence, [CJ]n is a Jacket matrix if and only if
0 1 1 0 0RT RT
nC C C C .
By using Proposition 2, we may construct many block circulant matrices.
One example of block circulant jacket matrices: Let
0
1 1
1 1C
, 1 1 1
a a
C
a a
(16)
Since 0 0 22RTC C I and 1 1 2
2RTC C I , 0C and 1C are Jacket matrices of order 2. Moreover,
0 1 1 0 2
1
1 1 1 101 1
1 1 1 1 1
RT RT
a aaa
C C C C
a a aa
. (17)
And we reach
0 1
1 0
1
1 1
1 1 1 11 11 1
1 1 1 1
1 1 1 1 1 1
1 1 1 1 1 11 1
n
a
a a
C C a aCJ
C C a a
a a
, (18)
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Therefore, [CJ]n is a block circulant inverse orthogonal Jacket matrix.
Circulant submatrices of size 2×2, are such that each submatrix has the property that all rows are cyclic shifts
of the first row and all columns are cyclic shifts of the first column. We shall refer to these submatrices as
circulant blocks. Also, we define user’s equivalence classes as the sets of user groups whose corresponding
columns of Hadamard matrices form circulant blocks. A circulant matrix is fully specified by one vector
which appears as its first column. Therefore, these matrices are important because they are diagonalized by
the DFT, and hence their linear equations can be quickly solved using the unitary fast Fourier transform.
4. Eigenvector and eigenvalue decomposition (EVD)
Because by Theorem 1, every Toeplitz Jacket matrix is equivalent to circulant matrices [9], it is natural to
look into details how the eigenvalues, eigenvectors, and eigenvalue decomposition (EVD) of a circulant
matrix can be obtained. Also note that in contrast to the usual symmetric matrix S (that have the propertyTS S ), the Toeplitz matrices and circulant matrices in particular are persymmetric [3]. This means that a real
matrixn nB ,
11 12 1
21 22 2
1 2
n
n
n n nn
b b b
b b bB
b b b
is persymmetric if it is symmetric about its northeast-southwest diagonal, i.e., for all 1 ,i j n , , 1, 1.i j n j n ib b
This is equivalent to requiring ,TB EB E where T is the transpose and E is the n×n exchange matrix
0 0 0 1
0 0 1 0
.
0 1 0 0
1 0 0 0
E
Lemma 2. If T is a Toeplitz (circulant) matrix, then the following statements are satisfied:
a) T is a persymmetric matrix;
b) If T is nonsingular, then its inverse 1T is also persymmetric.
In contrast to diagonal matrices whose eigenvalues are their diagonal elements [10], the numerical
determination of the eigenvalues of persymmetric matrices requires tedious calculation. Their
eigendecomposition depends on whether their dimension is odd or even.
We will delve into the EVD of circulant matrices following [1]. Let be the universal circulant matrix given
by
0 1 0 0
0 0 1 0
circ(0,1,0, ,0) .
0 0 0 1
1 0 0 0
(19)
It is easy to prove that a matrix C is circulant if and only if CΠ=ΠC
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Definition 1. Let n be a fixed integer ≥1 and 1i is the imaginary unit. Let 2
2 2cos sin .
i
ne in n
Denote
2 1( ) diag(1, , , , ).n
n (20)
Theorem 2. F F , where * is the conjugate transpose and F is the normalized matrix of the unitary
discrete Fourier Transform 0,0 0,1 0,( 1)
1,0 1,1 1,( 1)
2 i/
( 1),0 ( 1),1 ( 1),( 1)
1 1( ) .
n
n n n
n
jk n n n n
n n n n
n n n
F en n
(21)
Using the universal circulant matrix Π and Theorem 2, we have
Theorem 3. If C is circulant, it is diagonalized by F.
More precisely, ,C F F where 1diag( (1), ( ), , ( )),np p p for 1
0 1 1 .( ) n
np x c c x c x
If 2 ij
nj e
are the n-th roots of unity, the eigenvalues of C are 2 1
0 1 2 1 , 0,.... 1,n
j n j n j j j nc c c c
and the eigenvectors 1 , 0,1,..(1 ) . 1n T
j j jv j n .
As a consequence of the explicit formula for the eigenvalues above, the determinant of circulant matrix can be
computed as: 1
2 1
0 1 2 1
0
det( ) ( ).n
n
n j n j j
j
C c c c c
(22)
5. The Singular-value Decomposition
Using the Eq. (7) [9, Theorem 1.1], we can get to the diagonal matrices that can be used to replace the matrix
with circulant Jacket matrices. We have
44
1 0 0 0 1 0 0 0
0 0 0 0 0 0
( , , )0 0 0 0 0 0
0 0 0 0 0 0
c a
a c
CJ T a b cc a
a c
c c a a
a a c c
ab aba a
c c
ab aba a
c c
ab aba a
c c
ab aba a
c c
. (23)
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The Eq. (23) is enabled to have Jacket matrices in the pattern of 0 1
1 0
C C
C C
where
0
a
C
a
ab
c
ab
c
and 1
a
C
a
ab
c
ab
c
.
The characteristic polynomial of C is 3 2 2 2 2
2 2 2 3 4
2 22 2 2 2 2
16 16 4det( ) 4 4
4 4( 4 4 ) ( 2 ) ,
a b a b abC xI x a x x ax x
c c c
ab abx x a a x x a
c c
so the eigenvalues are 2 2
2 ,2 , ,i ab i ab
a ac c
and the eigenvectors are
{(0,1,0,1),(1,0,1,0),( , 1, ,1),( , 1, ,1)}.i i i i
Since we do not have any simple spectrum of the matrix C, we proceed with the singular value decomposition
(SVD):
4
1 1 1 10 0 0 0
2 0 0 02 2 2 20 2 0 01 1 1 1
0 0 0 022 2 2 2
0 0 01 1 1 1
0 0 0 02 2 2 22
0 0 01 1 1 1
0 0 0 02 2 2 2
.
T
a
a
abCJ
c
ab
c
(24)
Another example of the Toeplitz Jacket 6×6 matrix
6
1 1 11
3 9 27 81 243
1 1 13 1
3 9 27 81
1 19 3 1
3 9 27
127 9 3 1
3 9
181 27 9 3 1
3
243 81 27 9 3 1
w w
ww
ww
TJ
ww
w w
w w
, (25)
can be replaced with the circulant Jacket matrix using x=3i as
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1 2
0 1
1
5 2 5
6 6
0
diag(1, , , , ) diag(1, , , , )
circ(1, , , ,1, )
1 1
1 1
1 1
1 1
1 1
1 1
,
CJ x x x TJ x x x
i i i
i i i
i i i
i i i
i i i
i i i
i i i
C C
C C
(26)
where 0
1
1
1 1
i
C i i
i
, 1
1
1
i i
C i
i i
, and 2
31 3
2 2
i
e i
, respectively.
If n=8, a=1, and b=0, the circulant vector x(a,b)=x(1,0) is constructed as follows
2 2
22 21,0 exp exp exp
2 8 2 8i
ai ix bi i
n
i i i ,
Therefore, this vector looks like as
7 7
8 8 8 82 2 21,0 exp 1 ,exp 2 ,...,exp 8 , , 1, , ,18 8 8
i i i i
x e e e e
i i ii, i, .
Therefore, an instance of 8×8 CJ matrix [CJ]8(a,b) is given by
7 78 8 8 8
7 78 8 8 8
7 78 8 8 8
7 78 8 8 8
7 78 8 8 8
7 78 8 8 8
7 78 8 8 8
78
18 88 8
1, ,
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1
i i
i i
i i
i i
i i
i i
i i
i
i i i i
i i i i
i i i i
i i i i
i i i i
i i i i
i i i i
i
CJ a b D TJ a b Db
e e e e
e e e e
e e e e
e e e e
e e e e
e e e e
e e e e
e e
78 8 8
0 1
1 0
1ii i i
C C
C C
e e
, (27)
where
78 8
78 8
8 8
8 8
0
1
1
1
1
i
i
i
i
i i
i i
i i
i i
e e
e eC
e e
e e
,
78 8
78 8
7 78 8
7 78 8
1
1
1
1
1
i
i
i
i
i i
i i
i i
i i
e e
e eC
e e
e e
, the diagonal matrix 2 3 4 5 6 71, , ,a , , ,D diag a a a a a ,
the inverse of this diagonal matrix 1 2 3 4 5 6 71,1/ ,1/ ,1/ a ,1/ ,1/ ,1/D diag a a a a a , and Toeplitz-Jacket
matrix
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7 78 8 8 8
7 78 8 8 8
7 788 8 8
2
7 788 8 8
3 2
78 8
4 3 2
2 3 4 5 6 7
2 3 4 5 6
2 3 4 5
2 3 4
8,
i i i i
i i i i
ii i i
ii i i
i i
ba
be baa
ib be baa a
be ib be baa a a
be iab a be a b a be ia b a be a b
be iab a be a b a be ia b a be
be iab a be a b a be ia b
be iab a be a b a be
TJ a bbe
78 8
778 8
8 85 4 3 2
7 78 8 8
86 5 4 3 2
7 78 8 8
87 6 5 4 3 2
2 3
2
i i
i ii i
i i ii
i i ii
b be ib be baa a a a
be b be ib be baa a a a a
ib be b be ib be baa a a a a a
iab a be a b
be iab a be
be iab
be
.
We also note that from Eq. (27), the eigenvalue of 8×8 CJ matrices is 2 2 whose multiplicity is 8 as that of
8×8 DFT matrices.
6. Wireless MIMO Applications
We consider,
1
1 1 1
1
2 2 2
1
2 2 2
1
, ,H I T
I J Σ J
I J I Σ I J
JΣJ
n n n
n
n n n
a b c
(28)
where J is the n×n Jacket matrix that satisfies JJ-1
=I,
1 1
2
2 2 2
0
0
J
J=
Jn n
,
its inverse Jacket matrix
1 1
1
2
1
1
2 2 2
0
0
J
J =
Jn n
,
and Σ is the diagonal matrix given by
1 1
1
2
2 2 2
, ,
0
0
Σ J T J
Σ
Σ
n
n n
a b c
.
The well-known capacity formula is given by
2log det / ,H
n n nC bps Hz I H H (29)
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where γ = ρ / N0 is the signal-to-noise ratio (SNR), ρ is the energy of the transmitted signals, and N0 is the
power spectral density of the additive noise 1
n
i iz
. The SVD of H H
H
n nis given by
,H H H H H H H
n n H H JΣJ JΣ J JΣΣ J QΛQ (30)
where QQ IH and Λ
n n is the diagonal matrix with its elements given as
2
min
min
, 1,...,
0, 1,...
i
i
if i n
if i n n
. (31)
However, the system capacity can be written as
min
2
1
log 1 /r n
i
i
C bps Hzn
, (32)
where r = min(nmin, n) = nmin denotes the rank of Hn and
i is the eigenvalue of the matrix H HH
n n.
In Figure 1, we compare the inverse orthogonal Jacket channel against the conventional channel [11-12].
Using MATLAB software, we perform the Monte Carlo simulation at γ = 20[dBs] and generate by 1000
channel realizations in the simulations. We observe that in Figure 1, the channel capacity over the inverse
orthogonal channel is slightly increased at high SNR regime compared to Toeplitz and Jacket channels,
which can be a big help for meeting exponentially growing demand for higher capacity communication
systems.
Figure 1. Comparison of MIMO channel capacity employing Eq. (7) in Eq. (32).
7. Conclusions
To sum up, we have studied the CJ matrices that have a similar structure of a special kind of Toeplitz such as
traditional circulant matrices in this paper. The greatest advantages of these CJ matrices are that they facilitate
very fast and instantaneous computation of inverse CJ matrices stemming from the fact that inverse CJ
matrices are diagnosable by fast Fourier transform matrices and that they acquaint with the singular value
decomposition technique. There are many applications of CJ matrices such as the Kronecker MIMO channel
[6] and a block circulant Jacket in [11].
Acknowledgement
This work was supported by MEST 2015R1A2A1A05000977, NRF, Korea and thanks to Ferenc Szöllősi, he
has derived Eq. (27).
Journal of Engineering Technology Volume 6, Special Issue on Technology Innovations and Applications
Oct. 2017, PP. 389-402
404
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