Question

Generate a signal composed of two square waves, the first has a 14 Hz and the second has a 55 Hz frequency. Both waves are sampled at 2 kHz for 200 ms. Duty cycle for the first wave is 40% while the second’s is 35%. Show the signal with and without adding white Gaussian noise with a variance of 1/100 in matlab

Answer 1

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          Please find the answer attached as under. Please give a thumbs up rating if you find the answer useful! Have a rocking day ahead!

****** Matlab Code *******

Fs = 2e3;                                               % sampling freq
t = 0:1/Fs:(200e-3);                                    % time base
f1 = 14;                                                % frequencies of the pulses
f2 = 55;
pulsewidth1 = (40/100)*(1/f1);                          % ON periods
pulsewidth2 = (35/100)*(1/f2);
pulseperiods1 = [0:Fs*200e-3]*(1/f1);                   % time periods
pulseperiods2 = [0:Fs*200e-3]*(1/f2);
x1 = pulstran(t,pulseperiods1,@rectpuls,pulsewidth1);
x2 = pulstran(t,pulseperiods2,@rectpuls,pulsewidth2);
subplot(2,1,1);
plot(t,x1+x2);
xlabel('Time (s)');
title('Pulse without noise');

var = 1/100;
y = x1+x2+sqrt(var)*randn(size(t));
subplot(2,1,2);
plot(t,y);
xlabel('Time (s)');
title('Pulse with noise');

********* Output *********