%HBD3
clc;
clear all;
close all;
x=[1 1 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 1 0];
%x=[1 0 0 0 0 1 0 1 1 1 0 0 0 0 1 0 1];
%x=[0 0 0 0 0 1 1 1 0 0 0 0 1 0];
hdb3_code=x;
ami_code=x;
nx=size(x,2);
next_pulse=1;
sign=-1;
B=0;
V=1;
N=0;
i=1;
flag=0;
four_zero=0;
while i<nx+1
if x(i)==1
hdb3_code(i)=next_pulse;
next_pulse=next_pulse*-1;
N=N+1;
else
if i<nx-2
if (x(i+1)==0 & x(i+2)==0 & x(i+3)==0 )
if(rem(N,2)~=0 | flag==0)
B=0;
V=next_pulse*-1;
else
B=next_pulse;
V=B;
next_pulse=next_pulse*-1;
end
hdb3_code(i)=B;
hdb3_code(i+3)=V;
N=0;
flag=1;
four_zero=1;
end
end
end
if four_zero==1
i=i+4;
four_zero=0;
else
i=i+1;
end
end
x
hdb3_code
i=1;
while i<nx+1
t = i:0.001:i+1-0.001;
if x(i)==1
unipolar_code=square(t*2*pi,100);
bipolar_code=sign*square(t*2*pi,100);
sign=sign*-1;
else
unipolar_code=0;
bipolar_code=0;
end
subplot(3,1,1);
plot(t,unipolar_code);
ylabel('unipolar code');
hold on;
grid on;
axis([1 nx -2 2]);
subplot(3,1,2);
plot(t,bipolar_code);
ylabel('bipolar code');
hold on;
grid on;
axis([1 nx -2 2]);
subplot(3,1,3);
plot(t,hdb3_code(i)*square(t*2*pi,100));
ylabel('HDB3 code');
hold on;
grid on;
axis([0 nx+1 -2 2]);
i=i+1;
end
