Digital Signal Processing Reference
In-Depth Information
y(n)
x(n)
z/(z-0.3)
+
Time scope
z
-1
0.4
FIGURE 1.7
Simulink
®
model of a discrete-time system.
c.
Change sinusoidal signal amplitude (2V, 10V) and frequency (20
rad./s, 50 rad./s), and obtain the printouts of the output on the
time scope.
Exercise 4: Simulation of discrete-time LTI systems
a.
Create Simulink
®
models for the discrete-time system shown in
Figure 1.7. Please note that in all discrete-time simulation blocks,
the appropriate sampling time,
T
, sec. should be specified if
required.
b.
Obtain a printout of the output signal on the time scope, for an
input signal of
x
(
t
)
=
3 cos(2
5 sec.,
when the signal is sampled at a time interval of
T =
0.5 sec.
π
t
/5), in the time range 0
≤
t
≤
c.
Change the input signal amplitude to 6 volts and the input signal
frequency to twice its original value; observe the output on the
time scope. Obtain a printout of the output signal. Comment on
the differences between output signals obtained in part (b) and
part (c) of this exercise.
1.4
Hardware Laboratory: Working with Oscilloscopes,
Spectrum Analyzers, Signal Sources
Hardware equipment used in DSP applications can be classified into three
main categories.
1.4.1
Sinks or Measuring Devices
Sinks or measuring devices are used to accurately graph input signals in
two domains:
time
and
frequency
. The HP 54510A 100 MHz Digitizing Oscil-
loscope measures the amplitude and frequency of signals as a function of
time, whereas the HP 8590L RF Spectrum Analyzer measures the spectrum
