ber vs snr ofdm using fft and ifft

clc
clear
close all

%1
L=32;
m=(sign(randn(1,L))+1)/2;

%2
symbols = [-1i, -1, 1, 1i];
m2 = reshape(m, 2, []);
idx = m2(1,:) * 2 + m2(2,:) +1;
x = symbols(idx);

%3
S=16;
N=log2(S);
s=ifft(x);

%4
SNR_dB=[0:20];

for i=1:length(SNR_dB)
w(i,:)=sqrt(10.^(-SNR_dB(i)/10));
n=w*(randn(1,S)+1i*randn(1,S));
r=s+n;
x_=fft((r));
m1_=real(x_);
m2_=imag(x_);



end
% 
% semilogy(SNR_dB,SER,'-b.');
% title('SER VS SNR')
% xlabel(' SNR(dB) ');
% ylabel(' SER ');
% grid on;

Hey guys, im struggling on the BER VS SNR plot. I have different range of SNR and trying to demapping to original signal. How can I do that? I'm struggling on getting the correct BER.

Answer 1

[Roshni Garnayak]

Refer to the following link for examples and workflows for plotting bit error rate with respect to signal-to-noise ratio:

https://www.mathworks.com/help/comm/ug/bit-error-rate-ber.html