Digital Signal Processing Reference
In-Depth Information
performance, but the computational complexity of the latter is much lower than
that of the former.
The remainder of this chapter is organized as follows: In Section 6.2, we
review the 2-D nonparametric APES algorithm. In Section 6.3, we present 2-D
extensions of the MAPES-EM algorithms and develop the 2-D MAPES-CM al-
gorithm in Section 6.4. In Section 6.5, we compare MAPES-CM with MAPES-
EM,from both theoretical and computational points of view. Numerical examples
are provided in Section 6.6 to demonstrate the performance of the MAPES algo-
rithms.
6.2 TWO-DIMENSIONAL ML-BASED APES
In this section we provide the 2-D extension of APES, devised via a ML fitting
based approach, for complete-data spectral estimation.
Consider the 2-D problem introduced in Section 3.3.1. Partition the N 1
×
N 2 data matrix
y 0 , 0
y 0 , 1
···
y 0 , N 2 1
y 1 , 0
y 1 , 1
···
y 1 , N 2 1
Y
(6.1)
.
.
.
. . .
y N 1 1 , 1
···
y N 1 1 , N 2 1
y N 1 1 , 0
into L 1 L 2 overlapping submatrices of size M 1
×
M 2 :
y l 1 , l 2
y l 1 , l 2 + 1
···
y l 1 , l 2 + M 2 1
y l 1 + 1 , l 2
y l 1 + 1 , l 2 + 1
···
y l 1 + 1 , l 2 + M 2 1
Y l 1 , l 2
=
,
(6.2)
.
.
.
. . .
y l 1 + M 1 1 , l 2
y l 1 + M 1 1 , l 2 + 1
···
y l 1 + M 1 1 , l 2 + M 2 1
where
l 1
=
0
, ... ,
L 1
1
,
l 2
=
0
, ... ,
L 2
1
,
L 1
N 1
M 1
+
1,
and
L 2
1. Increasing M 1 and M 2 typically increases the spectral resolution
at the cost of reducing the statistical stability of the spectral estimates due to the
N 2
M 2
+
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