Digital Signal Processing Reference
In-Depth Information
4
2
0
−1
−0.5
0
0.5
1
Normalized Frequency (Multiples of
π
)
5
0
−5
−1
−0.5
0
0.5
1
Normalized Frequency (Multiples of
π
)
4
2
0
−1
−0.5
0
0.5
1
Normalized Frequency (Multiples of
π
)
4
2
0
−1
−0.5
0
0.5
1
Normalized Frequency (Multiples of
π
)
Figure 1.3:
(a) Magnitude of DTFT of the sequence [1,0,1]; (b) Phase of DTFT of same; (c) Real part
of DTFT of same; (d) Imaginary part of DTFT of same.
where
N
is the length of
x
. For the symmetrical time index option, the time indices are given as
n
=−
(N
−
1
)/
2
:
1
:
(N
−
1
)/
2
(n
odd
)
n
=−
N/
2
+
1
:
1
:
N/
2
(n
even
)
This script is useful for demonstrating the effect on the DTFT of time and frequency shifts to a
first test sequence. A typical call, which results in Fig. 1.4, is
nN = (0:1:100)/100;
LVxDTF T_MS([cos(2*pi*25*nN)],0,...
exp(j*2*pi*12.5*nN),200,2,2,1)
We will make use of these scripts shortly while studying the various properties of the DTFT.
