How to generate a discrete square pulse, lets say N times?

Lets say sample rate =20kHz symbol rate =1khz

[Naga Sai]

https://in.mathworks.com/matlabcentral/answers/155687-how-to-generate-a-discrete-square-pulse-lets-say-n-times#comment_238487

Answer 1

[Image Analyst]

Make up one cycle, then use repmat() to make as many copies as you want.

squareWave = repmat([1,1,1,1,0,0,0,0], [1, N]);

What is a "symbol rate"?

[Prajan Pradhan]

I want this type of pulse train but in discrete form. Do you know how to do it?

[Youssef Khmou]

it is the number of symbol change, the inverse of symbol duration time. simply from physics viewpoint, its the frequency of the waveform.

[Image Analyst]

I'm not familiar with that terminology. I see a period of 0.1 seconds, and a duty cycle of roughly 30%, and a sampling rate that can't be determined from the plot but he says it's 20,000 per second or 5e-05 seconds between samples.

Try this:

fontSize = 20;  
% One cycle in a 1/10 of a second = 2000 samples
oneCycle = zeros(1, 2000);
% Have a duty cycle of 30%, or 15% at the start and 15% at the end
% 15% of the elements = 300
oneCycle(1:300) = 1;
oneCycle(end-300:end) = 1;
% Now we have one cycle, use repmat to make 10 copies
tenCycles = repmat(oneCycle, [1, 10]);
% Set up the t axis
t = linspace(0, 1, length(tenCycles));
plot(t, tenCycles, 'b-', 'LineWidth', 2);
grid on;
xlabel('Seconds', 'FontSize', fontSize);
ylabel('Amplitude', 'FontSize', fontSize);
ylim([-0.5, 1.5]);

[Youssef Khmou]

the questioner said that he wants a discrete type of the square wave not the square wave itself, which is not clear yet.

[Image Analyst]

I don't understand the difference. Everything in computers is discrete/binary/digitized/quantized. And my plot looks just like the one he said he wanted.

[Youssef Khmou]

its true, waiting for some explanation.

[Image Analyst]

I don't think he will. I think he's ignoring this thread because he posted the same question here an hour after I gave my answer. Well, who knows. Maybe he will come back some day.

[Youssef Khmou]

i think 'discrete form' means a graph with '--' notation.

[Naga Sai]

sir how to generate a power spectrum for this Wave form

[Naga Sai]

Sir how to generate a power spectrum for this wave form

Answer 2

[Youssef Khmou]

You can either write the function or use built-in function, here is an example using 1000 samples :

       N=1e+3;
       Fs=20e+3;
       f=1e+3;
       Ts=1./Fs;
       t=0:Ts:N*Ts-Ts;
       y=square(2*pi*f*t);
       figure; plot(t,y);

[Prajan Pradhan]

You are using square function to generate square wave, what i want is square pulse in discrete form. I am confused using pulstran @rectpuls as it generates continuous rectangular pulses

[Image Analyst]

Yes, square() is in the Signal Processing Toolbox - do you have that toolbox? I have not heard of those two other functions you mention.