Digital Signal Processing Reference
In-Depth Information
0,5
0,5
Time domain
0,4
0,4
Duration of signal= 1 s
0,3
0,3
0,2
0,2
0,1
0,1
0,0
0,0
-0,1
-0,1
-0,2
-0,2
-0,3
-0,3
-0,4
-0,4
Period length of the sawtooth T = 765ms, i.e. 1,3 Hz
-0,5
-0,5
50
100
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250
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350
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950
50
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500
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600
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ms
ms
0,40
Frequency domain
0,30
That is
not
the amplitude -
spectrum of a periodic
sawtooth!
0,20
0,10
0,00
2,5
5,0
7,5
10,0
12,5
Hz
Illustration 194:
Digital non-periodicity
Here too the signal length is 1 s and the sampling frequency 32 Hz with a block length n = 32. However,
the frequency of the sawtooth is 1.3 Hz here and as a result does not fit into the time grid of the signal
segment. The amplitude spectrum has a completely irregular curve and is not identical to that of a periodic
sawtooth. On the other hand, it is a discrete line spectrum and must therefore belong to a periodic signal.
