MATLAB PROGRAM FOR DELTA MODULATION

Delta Modulation:

Its a modulation technique which is used for transmission of voice information where quality is not of much importance.It is one of the simplest form of differential Pulse Code Modulation.
Characteristic of Delta Modulation:
     1.  Series of segments is used to approximate the analog signal.
     2.  Segment of the approximated signal is compared to the original analog signal to determine the              change  in relative amplitude.
     3.  The above process help us in establishing the state of successive bits(0 or 1).
     
Here we have a simple MATLAB program to generate delta modulated signal 

DELTA MODULATION Using MATLAB

clc;
clear all;
close all;
a=2;
t=0:2*pi/50:2*pi;
x=a*sin(t);
l=length(x);
plot(x,'r');
delta=0.2;
hold on
xn=0;
for i=1:l;
if x(i)>xn(i)
d(i)=1;
xn(i+1)=xn(i)+delta;
else
d(i)=0; xn(i+1)=xn(i)-delta;
end
end
stairs(xn)
hold on
for i=1:d
if d(i)>xn(i)
d(i)=0;
xn(i+1)=xn(i)-delta;
else
d(i)=1; xn(i+1)=xn(i)+delta;
end
end
plot(xn,'c');
legend('Analog signal','Delta modulation','Demodulation')
title('DELTA MODULATION / DEMODULATION ')