newrayleigh.m

matlab program for simulating Rayleigh fading channel

N=10^5;
ip = rand(1,N)>0.5;
x = 2*ip - 1;

t=2000;
b=(12/t)^0.5;
for j=1:N
        u = rand(1,t);
        k = sum(u-0.5);
        n1(j) = b*k;% n:gnoise signal
        n1(j) = n1(j)*n1(j);
end

for j=1:N
        u=rand(1,t);
        k=sum(u-0.5);
        n2(j)=b*k;% n:gnoise signal
        n2(j) = n2(j)*n2(j);
end

for j=1:N
        u=rand(1,t);
        k=sum(u-0.5);
        n3(j)=b*k;% n:gnoise signal
end

a=(n1 + n2);
e=sum(a)/N;
s2n= [-3:13];
for i=1:length(s2n)
    for j=1:N
        s(j) = (a(j)^0.5)*x(j) + 10^(-s2n(i)/20)*n3(j);
    end
    op = s>0;
    err= xor(op,ip);
    ber(i)=sum(err)/N;
end
TheoryBer = berfading(s2n,'psk',2,1);
% plot
close all
figure
semilogy(s2n,TheoryBer,'b.-');
hold on
semilogy(s2n,ber,'mx-');
%axis([-3 10 10^-5 0.5])
grid on
legend('theory', 'simulation');
xlabel('Eb/No, dB');
ylabel('Bit Error Rate');
title('BER curve for BPSK modulation in Rayleigh fading channel');