Complete the given Matlab code to build an Amplitude Shift Keying (ASK) simulator, write your Matlab code on the %% Modulation and Demodulation Functions section, for a square signal On-Off Keying (OOK) modulation and demodulation. Once finished, run the simulations required to plot BER curves with a minimum probability of bit error of 10^-4.

Plots:

BER vs SNR (dB) plot in the same graph, plot at least 4 BER curves corresponding to different values of symbol periods and pulse widths.

Transmitted signal plot plot the transmitted signal corresponding to 3 bits.

Received signal plots for the transmitted signal (3 bits), plot the received noisy signal for at least 4 values of SNR (e.g. 0 dB, 10 dB, 20 dB, 30 dB).

%% Main Function

function runComm()

clear;clc;

SNRdB = 20:0.5:30;

nBits = 1e5;

SNRdBLength = length(SNRdB);

Pe = ones(1,SNRdBLength);

clc; disp('Simulation running: 0.0% completed.');

for i = 1:SNRdBLength

Pe(i) = transmitReceive(nBits,SNRdB(i));

clc;fprintf('%s: %.1f%% completed','Simulation running',i/SNRdBLength*100);

end

hold on; semilogy(SNRdB,Pe); grid on;

clc; disp('Simulation finished.');

return

%% Bit Transmission Function

function [Perror,nErrors,TxBits,RxBits] = transmitReceive(nBits,SNRdB)

% TxBits = [0 1 1 0 1 0 0 1 1 1];

nBitsMax = 100000;

nBitsOrig = nBits;

TxBits = [];

RxBits =[];

if(nBits > nBitsMax)

n = ceil(nBits/nBitsMax);

nErrorsArr = zeros(1,n);

for i = 1:n

if(nBits < nBitsMax)

[~,nErrorsArr(i),TxBitsTmp,RxBitsTmp] = transmitReceive(nBits,SNRdB);

TxBits = [TxBits,TxBitsTmp];

RxBits = [RxBits,RxBitsTmp];

break;

else

[~,nErrorsArr(i),TxBitsTmp,RxBitsTmp] = transmitReceive(nBitsMax,SNRdB);

TxBits = [TxBits,TxBitsTmp];

RxBits = [RxBits,RxBitsTmp];

nBits = nBits - nBitsMax;

end

end

nErrors = sum(nErrorsArr);

Perror = nErrors/nBitsOrig;

return;

end

TxBits = round(rand(1,nBits));

TxSignals = modulation(TxBits);

[RxSignals] = addAWGNoise(TxSignals,SNRdB);

RxBits = demodulation(RxSignals);

errorBits = TxBits ~= RxBits;

nErrors = sum(errorBits);

Perror = nErrors/nBits;

return

%% Modulation and Demodulation Functions

function [outSignals,time] = modulation(inBits)

%Your code here

return

function [outBits] = demodulation(inSignals)

%Your code here

return

%% Noise Adding Function

function [outSignals,noiseSignals] = addAWGNoise(signals,SNRdB)

signalsSize = size(signals);

SNR = 10^(SNRdB/10);

Ps = max(sum(signals.^2));

Po = Ps./SNR;

noiseSignals = sqrt(Po/2).*randn(signalsSize(1),signalsSize(2));

outSignals = signals+noiseSignals;

return

%% Signal Creation Functions

function [outSignal,time] = pulseSignal(Tp,Tw,osFactor)

if(nargin == 2), osFactor = 1; end

if(osFactor < 1), osFactor = 1; end

B = 1.5/Tp;

fs = osFactor*2*B;

Nw = ceil(fs*Tw);

Np = ceil(fs*Tp);

outSignal = [0; ones(Np,1); zeros(Nw-Np-1,1)];

outSignal(end)=0;

time = (0:length(outSignal)-1)'/fs;

return

function [outSignal] = squareSignal(time,freq)

tsample = time(2)-time(1);

tperiod = 1/freq;

n = ceil(tperiod/tsample);

npos = ceil(n/2);

nneg = n - npos;

Nperiods = ceil(time(end)*freq);

signalTmp = [ones(npos,1); -1*ones(nneg,1)];

outSignal = repmat(signalTmp,Nperiods+1,1);

outSignal = [ 0; outSignal(1:length(time)-1) ];

return