blob: b622f9277df8345bfbb1c38f32e3f044d68c0fc0 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
|
clc;
//page 199
//problem 4.2
//Given angle modulated signal is x = 3*cos[2*pi*(10^6)*t+2*sin(2*pi*10^3*t)]
//So, phase of the angle modulates signal is Q = 2*pi*(10^6*t)+2*sin(2*pi*(10^3)*t)
//Instantaneous frequency = dQ/dt = 2*pi*(10^6)+ 4*pi*(10^3)*sin(2*pi*(10^3)*t)
//For Instantaneous frequency at 0.25ms, Substituting t = 0.25ms in Instantaneous frequency
//Instantaneous frequency is expressed as f1_rad for frequency in radians per second
f1_rad = 2*%pi*(10^6)+ 4*%pi*(10^3)*sin(2*%pi*(10^3)*0.00025)
//Instantaneous frequency is expressed as f1_hz for frequency in hertz
f1_hz = f1_rad/(2*%pi)
disp('the Instantaneous frequency at time t=0.25ms is '+string(f1_rad)+' rad/sec = '+string(f1_hz)+' Hz')
//For Instantaneous frequency at 0.25ms, Substituting t = 0.5ms in Instantaneous frequency
//Instantaneous frequency is expressed as f2rad for frequency in radians per second
f2_rad = 2*%pi*(10^6)+ 4*%pi*(10^3)*sin(2*%pi*(10^3)*0.0005)
//Instantaneous frequency is expressed as f2hz for frequency in hertz
f2_hz = f2_rad/(2*%pi)
disp('the Instantaneous frequency at time t=0.5ms is '+string(f2_rad)+' rad/sec = '+string(f2_hz)+' Hz')
//Maximum phase deviation = max[2*sin(2*pi*(10^3)*t)] = 2*1
maxDp = 2;
disp('Maximum phase deviation is '+string(maxDp)+' rad')
//Maximum frequency deviation = max[4*pi*(10^3)*sin(2*pi*(10^3)*t)] = 4*pi*(10^3)*1
maxDf = 4*%pi*(10^3)*1;
disp('Maximum frequency deviation is '+string(maxDf)+' Hz')
//disp('in rad',maxDf,'Maximum frequency deviation is')
//In the textbook the calculated value of max frequency devaition is = 2000 Hz, in reality the value = 12566.371 Hz
|
