Randi Error- Array exceeds max array size preference

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')

Answer 1

[Jeff Miller]

This looks wrong:

OOK=randi(1,sig_length);

The first parameter (here, 1) is the maximum random integer (the minimum is 1). Since the max is the same as the min, this randi command will only produce 1's.

The second and third parameters give the size of the array you want. So I suspect you really want something like

myMax = 10;  % whatever max you want
OOK = randi(myMax,1,sig_length);