Coincidence detector in Matlab

How to make coincidence detector on MATLAB In the picture, signal 5 is result of coincidence detector for signal 1 and signal 3

Signal 6 is result of coincidence detector for signal 2 and signal 4.

Thank you.

[Matt Kindig]

Are you doing this in Matlab itself or Simulink?

[Mail Abos]

just in Matlab

Answer 1

[Matt Kindig]

How about something like this? (I assume all signals are sampled synchronously).

edges1 = find(diff(Signal1) > 0);  %get rising edges on Signal 1
edges3 = find(diff(Signal3) > 0);  %get rising edges on Signal 3
commonEdges = intersect(edges1, edges3);  %these are the indices of the coincident edges.

Note that this assumes that the rising edges are at identical locations. If there is any timing errors, this simple approach won't work.

[Mail Abos]

We already try like this, but we get error problem, please help.

dt = 1e-9; % time increment (in seconds)

maxtime = 20e-6; % maximum length of signal (in seconds)

time = 0:dt:maxtime; % time samples (in seconds)

wavelength = 2e-6; % distance between beginning of each pulse

wavewidth = 0.5e-6; % width of each pulse

rectpulse = ones(1,round(wavewidth/dt)); % Define width of rectangle pulse

operator = zeros(size(time)); % Set operator to zeros

operator(mod(time,wavelength)==0) = 0.75; % Place 0.75 at each pulse location

rectsignal = conv(operator,rectpulse); % Convolve rectpulse w/ operator

rectsignal1 = rectsignal(1,1:length(time)); % Remove any extra

subplot(2,1,1); plot(time,rectsignal1);

title('signal1');

dt = 1e-9; % time increment (in seconds)

maxtime = 20e-6; % maximum length of signal (in seconds)

time = 0:dt:maxtime; % time samples (in seconds)

wavelength = 3e-6; % distance between beginning of each pulse

wavewidth = 0.5e-6; % width of each pulse

rectpulse = ones(1,round(wavewidth/dt)); % Define width of rectangle pulse

operator = zeros(size(time)); % Set operator to zeros

operator(mod(time,wavelength)==0) = 0.75; % Place 0.75 at each pulse location

rectsignal = conv(operator,rectpulse); % Convolve rectpulse w/ operator

rectsignal2 = rectsignal(1,1:length(time)); % Remove any extra

subplot(2,1,2); plot(time,rectsignal2);

title('signal2');

edges1 = find(diff(rectsignal1) > 0); %get rising edges on Signal 1

edges3 = find(diff(rectsignal2) > 0); %get rising edges on Signal 2

commonEdges = intersect(edges1, edges3); %these are the indices of the coincident edges

subplot(2,1,3); plot(commonEdges)

Error using subplot (line 308) Index exceeds number of subplots.

[Matt Kindig]

Is the subplot error you've indicated here your only problem? The error is thrown because

subplot(2,1,3)

attempts to create a 2x1 grid of two subplots. However, you are attempting to call subplot 3 (which does not exist). Change your subplot call to subplot(3,1,3) and it will work.