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
|
// Example no 8.1
// To compute the mean square error distortion and output signal-to-distortion ratio.
// Page no. 420
clc;
clear all;
//Given data
l1=1; // 1st Quantization level
l2=3; // 2nd Quantization level
l3=5; // 3rd Quantization level
l4=7; // 4th Quantization level
U1=(l1+l2)/2; // upper boundary of 1st level
U2=(l2+l3)/2; // upper boundary of 2nd level
U3=(l3+l4)/2; // upper boundary of 3rd level
U4=l4+(U1-l1); // upper boundary of 4th level
L1=l1-(U1-l1); // Lower boundary of 1st level
D1=integrate('(x^3-2*x^2+x)/32','x',L1,U1); // Mean square error distortion of 1st level
D2=integrate('(x^3-6*x^2+9*x)/32','x',U1,U2); // Mean square error distortion of 2nd level
D3=integrate('(x^3-10*x^2+25*x)/32','x',U2,U3); // Mean square error distortion of 3rd level
D4=integrate('(x^3-14*x^2+49*x)/32','x',U3,U4); // Mean square error distortion of 4th level
D=D1+D2+D3+D4; // Total square error distortion
P=integrate('x^3/32','x',L1,U4); // Signal power
SDR=10*log10(P/D); // Output signal-to-distortion ratio.
// Displaying the result in command window
printf('\n The mean square error distortion = %0.3f',D);
printf('\n The output signal-to-distortion ratio = %0.2f dB',SDR);
printf('\n To minimize the distortion, we need to place the quantization levels closer at amplitudes close to 8 and farther at amplitudes close to zero.');
printf('\n This quantizer would be optimal for an input with a uniform pdf.');
|
