DTFT, DFT, ZT, and FFT 547
0 5 10
time index n
15 20 25
0 5 10
time index n
15 20 25
Amplitude
− 1
0
1
2
Amplitude
− 1
0
1
2
[IDFT of the products of the DFTs] versus n
[Direct convolution in the time domain] versus n
FIGURE 5.61
Plots of g(n) = IDFT of the products of DFT[h(n)] with DFT[f (n)], and time convolution of h(n) with f(n) of Exam-
ple 5.14.
0 5 10
[Impulse response h(n)] versus n
[Input sequence f(n)] versus n
15
(^051015)
time index n
Amplitude
−0.5
0
0.5
1
Amplitude
− 1
−0.5
0
0.5
1
FIGURE 5.60
Plots of f(n) and h(n) of Example 5.14.