2.m

通原实验课的作业

close all 
clear all
echo on
t=0:0.001:2;
a(1:length(t)/2)=t(1:length(t)/2);
a(length(t)/2:length(t))=-t(length(t)/2:length(t))+2;%信号样本序列 
figure(1)
plot(t,a);
title('信源序列')
n=8;
[sqnr,a_quan,code]=u_pcm(a,8);
sqnr  
figure(2)
plot(a,a_quan,'-');
title( '量化级数为8的输入输出关系')

n=16;
[sqnr,a_quan,code]=u_pcm(a,16);
sqnr  
figure(3)
plot(a,a_quan,'-');
title( '量化级数为16的输入输出关系')

n=64;
[sqnr,a_quan,code]=u_pcm(a,64);
sqnr
figure(4)
plot(a,a_quan,'-');
title( '量化级数为64的输入输出关系')

f=a-a_quan;                 %量化误差等于原始值与量化值的差
figure(5)
[sqnr,a_quan,code]=u_pcm(a,8);
subplot(3,1,1);
axis([0 500 -1 1]);
plot(t,f,'-');
title('量化误差,从上到下量化级数分别为8,16,64')

[sqnr,a_quan,code]=u_pcm(a,16);
f=a-a_quan;                 
subplot(3,1,2);
axis([0 500 -1 1]);
plot(t,f,'-');


[sqnr,a_quan,code]=u_pcm(a,64);
f=a-a_quan;                 
subplot(3,1,3);
axis([0 500 -1 1]);
plot(t,f,'-');