Matlab code to verify the adaptive delta modulation

Code:

clc               

clear all;

t =0:1/29:1;

f=1;

x=4*sin(2*pi*f*t);

x=[x ones(1,10) x]; 

y = zeros(1,length(x));

d = zeros(1,length(x));

e= zeros(1,length(x));

s=0.1;

for i=5:length(x)

if(x(i)-y(i-1))>=0

      y(i) = x(i)-s;

        d(i)=-1;

elseif(x(i)-y(i-1))<0

y(i)=x(i)-1;

d(i)=-1;       

end 

 

if(sum(d(i-4:i)))>3

s=s+0.01;

elseif(sum(d(i-4:i)))<-3

  s=s+0.01;

elseif(sum(d(i-4:i)))==0

s=s-0.01;

else

s=s;

end

pause;

subplot 211; plot(x); hold on;

stem(y,'m');e=x-y;plot(e,'r');

title('Input,tracking and error graph');

subplot 212; stem (d,'k'); title('output data signal')

end

Output: