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Is there any elegant way to generate a pulse train with random magnitude in Matlab?

Given the time sequence t and period T, I would like to generate a rectangular pulse train with random magnitude in Matlab like in the figure below:

random pulse train

I used the square function and generate the figure like below, but the magnitude is not the same in a period. I want the magnitude remains the same in a period.

my try

Is there an efficient and elegant way in Matlab?

Solution

  • You can generate a set of random pulse heights, then for each point turn it into a pulse (where the signal is non-zero) and a "gap" (where the signal is 0).

    Here is some example code, see the comments for details

    numPulses = 20;   % number of pulses to generate
pulseWidth = 10;  % width (in samples) of each pulse
gapWidth = 15;    % width (in samples) of each gap between pulses
pulseMin = 3;     % minimum pulse height
pulseMax = 10;    % maximum pulse height

% generate array of random pulse heights
pulseHeights = rand(1,numPulses) * (pulseMax-pulseMin) + pulseMin;

% Make all of the final samples, defined as either a pulse or a gap
pulses = repmat( pulseHeights, pulseWidth, 1 );
gaps = zeros( gapWidth, numPulses );

% Turn the matrix of pulses/gaps into a single array
signal = reshape( [pulses; gaps], [], 1 );

% Plot. Using the 'stairs' function gives straight edges, but could use 'plot'
figure; 
stairs( signal );
ylim( [-1, pulseMax+1] );

    plot