88
Practical MATLAB
® Applications for Engineers
Binary information signal
ASK signal
4
3
2
1
0
Amplitude
Amplitude
Amplitude
Amplitude
0
1
2
3
4
time
4
2
−2
−4
0
0
1
2
3
4
time
PSK signal
1
0.5
−0.5
−1
0
0.5
1
0
1.5
time
FSK signal
1
0.5
−0.5
−1
0
1
0
2
3
4
time
FIGURE 1.74
Plots of ASK, FSK, and PSK telecommunication signals for a binary information signal of Example 1.18.
Information signal: 3*cos(5*t)
6
4
2
0
−2
−4
−6
Amplitude
Amplitude
0
1
2
3
Amplitude
Amplitude
Carrier signal: cos(50*t)
1.5
1
0.5
0
−0.5
−1
−1.5
0
0
0.5
1
1.5
2
0.1
0.2
0.3
0.4
Angle Modulated signal
time
6
4
2
−2
−4
−6
0
time
time
AM (Amplitude Modulated) signal
6
4
2
0
−2
−4
−6
0
1
2
3
time
FIGURE 1.73
Plots of standard analog telecommunication signals of Example 1.18.
Example 1.19
Given the following time functions:
f 1 (t) = cos(2t) + 2 sin(3t)
and
f 2 (t) = 10 sin(2t)e
−t/π
over the range 0 ≤ t ≤ 2π.
CRC_47760_CH001.indd 88
CRC_47760_CH001.indd 88
7/25/2008 4:16:28 PM
7/25/2008 4:16:28 PM