adcom_codes.md

ERRORS (FIX)

% sequence y is undefined
y = [];
% comment y(j) = y(j-1) if error
%Add these 4 line in all codes
clc
clear all
close all
y =[ ];

dont study BIPOLAR RZ(AMI) (NEW)

h = [1 1 1 1 0];

x = 1;
for i=1:length(h) % change ones to alternate plus minus
    if h(i) == 1
       h(i) = x;
       x = -x;
    end
end

k=1;
a = 0;
b = 0.5;
t=0:0.01:length(h);
for j=1:length(t)
    if t(j) >= a && t(j) <= b
        y(j) = h(k);
    elseif t(j) >b && t(j) <= k
        y(j) = 0;
    else
        k = k + 1;
        a = a + 1;
        b = b + 1;
    end
end

plot(t, y)
title('Bipolar RZ');
axis([0 length(h) -2 2]);

dont study MANCHESTER LINE CODE(NEW)

h = [1 0 0 1 1 0 1 0 1 0];

h(h<=0) = -1; % change all 0's to -1

l=1;
a=0;
b=0.5;
t=0:0.01:length(h);
for j=1:length(t)
    if t(j) >=a && t(j) <=b
        y(j) = h(l);
    elseif t(j)>=b && t(j)<=l
        y(j) = -1*h(l) %invert output after t crosses 0.5
    else
        y(j) = y(j-1); % remove spikes assign a previous value
        l = l+1;
        a = a+1;
        b = b+1;
    end
end
plot(t,y);
title('Manchester line code');
axis([0 length(h) -2 2]);

HALF SINE (NEW)

f = 2;
fs = f*20;
t = 0:1/fs:1;
y = sin(2*pi*f*t);
y(y<0) = 0;
plot(t,y)

RAISED COSINE

fs = 200;
fd = 5;
y = rcosine(fd,fs);
figure(1)
plot(y)

PCM

 f = 2;
 fs = f*20;
 t = 0:1/fs:1;
 a = 2;
 x = a*sin(2*pi*f*t);
 x1 = x+a;
 quantized = round(x1);
 encoded = de2bi(quantized,'left-msb');
 decoded = bi2de(encoded,'left-msb');
 reconstructed = decoded - a;
 plot(t,x,'r-',t,reconstructed,'k+-');
 xlabel('time');
 ylabel('amplitude');
 legend('original signal','reconstructed signal');

QPSK

BER = runQPSKSystemUnderTest(commqpsktxrx_init, true, false);
disp('Error rate')
disp(BER(1))
disp('Number of detected errors');
disp(BER(2))
disp('Total number of compared samples')
disp(BER(3))

EYE DIAGRAM

fs = 20;
fd = 1;
pd = 200;
m = 5;
x = randi([0 m-1],pd,1); % new matlab %help("randi")
% x = randint(pd,1,m);  %old matlab
delay = 3;
r = 0.01;
rcv = rcosflt(x,fd,fs,'fir/normal',r,delay);
n = fs/fd;
eyediagram(rcv,n)

DPSK

M = 4; 
x = randi([0 M-1],500,1); % Random data
y = dpskmod(x,M,pi/8); 
plot(y) 

POLAR NRZ

%h = [1 0 0 1 1 0 1 0 1 0];
h = input('Enter the input: '); %Enter the input inside square bracket eg. [1 0 1 0 0 1]

h(h<=0) = -1; % change all 0's to -1

l=1;
t=0:0.01:length(h);
for j=1:length(t)
    if t(j) < l
        y(j) = h(l);
    else
        y(j) = h(l);
        l = l + 1;
    end
end

plot(t, y)
title('Line code POLAR NRZ');
axis([0 length(h) -2 2]);

POLAR RZ LINE CODING

%h = [1 0 0 1 1 0 1 0 1 0];
h = input('Enter the input: '); %Enter the input inside square bracket eg. [1 0 1 0 0 1]

h(h<=0) = -1; % change all 0's to -1

l=1;
a=0;
b=0.5;
t=0:0.01:length(h);
for j=1:length(t)
    if t(j) >=a && t(j) <=b
        y(j) = h(l);
    elseif t(j)>b && t(j)<=l
        y(j) = 0;
    else
        l = l+1;
        a = a+1;
        b = b+1;
    end
end

plot(t,y);
title('Line code POLAR RZ');
axis([0 length(h) -2 2]);