This is the code that I have, however, I get an error and I dont know if theres's a way to fix this:
% Simulate BER of OOK-NRZ
clear;
clc;
close all
q=1.6e-19;
% Charge of Electron
Ib=202e-6;
% Background Noise Current+interfernce
N0=2*q*Ib;
% Noise Spectral Density, 2*q*Ib
R=1;
% Photodetector responsivity
Rb=1e6;
% Bit rate
Tb=1/Rb;
% bit duration
sig_length=1e5;
% number of bits
nsamp=10;
% samples per symbols
Tsamp=Tb/nsamp;
% sampling time
EbN0=1:12;
% signal-to-noise ratio in dB.
SNR=10.^(EbN0./10);
% signal-to-noise ratio
% ********** Simulation of probability of errors. ************
for i=1:length(SNR)
P_avg(i)=sqrt(N0*Rb*SNR(i)/(2*R^2));
% average transmitted optical power
i_peak(i)=2*R*P_avg(i);
% Peak Electrical amplitude
Ep(i)=i_peak(i)^2*Tb;
% Peak energy (Energy per bit is Ep/2)
sgma(i)=sqrt(N0/2/Tsamp);
% noise variance
%sgma(i)=i_peak(i)/sqrt(2)*sqrt(nsamp/(2*SNR(i)));
pt=ones(1,nsamp)*i_peak(i);
% tranmitter filter
rt=pt;
% receiver filter matched to pt
OOK=randi(1,sig_length);
% random signal generation
Tx_signal=rectpulse(OOK,nsamp)*i_peak(i);
% Pulse shaping function (rectangular pulse)
Rx_signal=R*Tx_signal+sgma(i)*randn(1,length(Tx_signal));
% received signal (y=x+n)
MF_out=conv(Rx_signal,rt)*Tsamp;
% matched filter output
MF_out_downsamp=MF_out(nsamp:nsamp:end);
% sampling at end of bit period
MF_out_downsamp=MF_out_downsamp(1:sig_length);
% truncation
Rx_th=zeros(1,sig_length);
Rx_th(find(MF_out_downsamp>Ep(i)/2))=1;
% thresholding
[nerr ber(i)]=biterr(OOK,Rx_th);
% bit error calculation
end
figure;
semilogy(EbN0,ber,'b');
hold on
semilogy(EbN0,qfunc(sqrt(10.^(EbN0/10))),'r-X','linewidth',2);
% theoretical ber, 'mx-');
grid on
legend('simulation','theory');
xlabel('Eb/No, dB');
ylabel('Bit Error Rate');
title('Bit error probability curve for OOK modulation')
