clear;
bits = 64;
threshold = 0.5;

%Generate 64 random values. Check help on rand() function.
data = rand(1, bits);

%Quantize the random values only between two levels; 0 and 1.
for i=1:length(data)
    if data (i) > threshold
        data2(i) = 1;
    else
        data2(i) = 0;
    end
end

%Commands for plotting the data.
subplot(4, 1, 1); 
stairs(data2)
title('Original Digital Data');
ylabel('Amplitute');
axis([0 bits -0.2 1.2]);
grid off;

%%%%%%%%%%%%%%%Enconding using NRZ-L%%%%%%%%%%%%%%%%%%%%%%%
%nrzl_enc is a function defined in another file nrzl_enc.m
data3 = nrzl_enc(data2);

%Commands for plotting the data.
subplot(4, 1, 2); 
stairs(data3)
title('NRZ-L Encoded Digital Data');
ylabel('Amplitute');
axis([0 bits -1.2 1.2]);
grid off;
%%%%%%%%%%%%%%%Enconding using NRZ-L%%%%%%%%%%%%%%%%%%%%%%%


%%%%%%%%%%%%%%%Expand Your Sammple Space%%%%%%%%%%%%%%%%%%%
sampleRate = 16;
Y1 = reshape(ones(sampleRate, 1)*data3, 1, sampleRate*bits);
%%%%%%%%%%%%%%%Expand Your Sammple Space%%%%%%%%%%%%%%%%%%%

%%%%%%%%%%%%%%%FFT%%%%%%%%%%%%%%%%%%%
N=sampleRate*bits;
FFT_Y1 = abs(fft(Y1, N));
FFT_Y1 = fftshift(FFT_Y1);
F = [-N/2:N/2-1]/N;;
subplot(4, 1, 3); 
plot(F, FFT_Y1);
xlabel('frequency / f s')
%%%%%%%%%%%%%%%FFT%%%%%%%%%%%%%%%%%%%