Digital Signal Processing Reference
In-Depth Information
Exercise 6
(a)
Develop a circuit with which you can represent the time window types of the "Data
window" module graphically as in Illustration 54
(b)
Compare the frequency curve of these various different time windows as in Illustra-
tion 54 on the right.
(c)
Take a longish filtered noisy signal and try as in Illustration 52 to carry out the
"windowing" by means of staggered overlapping GAUSSian windows.
(d)
Present the spectrum of these signal segments in a time-frequency landscape.
Exercise 7
Examine the pulse response h(t) of various different low-pass filters in the time and
frequency domain.
Time domain
Spectr um
Fr eq. domain
del ta-pulse
LP filter
1,00
0,008
0,007
0,006
0,005
0,004
0,003
0,002
0,001
0,000
0,008
0,007
0,006
0,005
0,004
0,003
0,002
0,001
0,000
0,010
0,009
0,008
0,007
0,006
0,005
0,004
0,003
0,002
0,001
0,000
0,75
Impulse response LP 1 (Butterworth)
Spectrum of the
impulse response
( frequency
response)
0,50
0,25
0,00
-0,25
-0,50
1,25
1,00
Spectrum of the
impulse response
(frequency response)
0,75
Impulse response LP 2 (Bessel)
0,50
0,25
0,00
-0,25
1,00
0,75
Spectrum of the
impulse response
(frequency response)
Impulse response LP 3 ( Tschebycheff)
0,50
0,25
0,00
-0,25
-0,50
0
25
50
75
100
125
150
175
200
225
250
275
0
25
50
75
100
125
150
175
200
225
250
275
300
ms
Hz
Illustration 66:
Pulse response and transfer function
