matlab实现A律13折线的编码和译码以及量化误差的计算

%judge函数
function [B,m1,n1]=judge(I,m,n)
if I>=m&&I<(m+n)/2
B=0;
m1=m;
n1=(m+n)/2;
else
B=1;
m1=(m+n)/2;
n1=n;
end

%主函数如下
clear all;
clc;
figure(7)
fc=2000;
t=0:1/2000:1;
m=2000sin(100pit);
subplot(311);
plot(t,m);%抽样序列
axis([0 0.02 -2000 2000]);
title(‘抽样序列’);
xlabel(‘t(s)’);
for i=1:length(m)
if m(i)>0 %确定极性码
B1=1;
else
B1=0;
end
m(i)=abs(m(i));
C=[0 16 32 64 128 256 512 1024 2048];%A律13折现非均匀区间
for j=1:length©;
if m(i)>=C(j)&&m(i)<=C(j+1)
L=j-1;
L1=dec2bin(L,3);
B2=L1(1);
B2=str2num(B2);
B3=L1(2);
B3=str2num(B3);
B4=L1(3);
B4=str2num(B4);
end
end
a=C(L+1);%确定段内码
b=C(L+2);
[B5,a1,b1]=judge(m(i),a,b);
[B6,a2,b2]=judge(m(i),a1,b1);
[B7,a3,b3]=judge(m(i),a2,b2);
[B8,a4,b4]=judge(m(i),a3,b3);
result(i,1)=B1;
result(i,2)=B2;
result(i,3)=B3;
result(i,4)=B4;
result(i,5)=B5;
result(i,6)=B6;
result(i,7)=B7;
result(i,8)=B8;
end
%以下为A律13折线译码
C2=[0,16;16,32;32,64;64,128;128,256;256,512;512,1024;1024,2048];
step=[1,1,2,4,8,16,32,64];
for i=1:2000
temp(i,1)=result(i,1);
temp(i,2)=bin2dec(num2str(result(i,2:4)));
temp(i,3)=bin2dec(num2str(result(i,5:8)));
end
for i=1:2000
position=floor((m(i)-C2(temp(i,2)+1,1))/step(temp(i,2)+1));
result2(i)=C2(temp(i,2)+1,1)+positionstep(temp(i,2)+1)+0.5step(temp(i,2)+1);
if temp(i,1)==0
result2(i)=-result2(i);
end
end
subplot(312);
t2=0:1/2000:1999/2000;
plot(t2,result2);
axis([0 0.02 -2000 2000]);
title(‘PCM译码信号（即量化信号）’);
xlabel(‘t(s)’);
m=2000sin(100pit);
for i=1:2000
error(i)=result2(i)-m(i);
end
subplot(313);
plot(t2,error);
axis([0 0.02 min(error)-1 max(error)+1]);
title(‘量化误差’);
xlabel(‘t(s)’);

运行结果