MATLAB Coder for FSK Demodulation

Hello,

I am trying to generate c code for FSK Modulation and Demodulation. Following is my function for code generation:

function [modSignal,receivedData,errorStats] = test_my_FSK(data)
%#codegen

M = 4;
freqSep = 100;

fskMod_M = comm.FSKModulator(M,freqSep,'BitInput',true);

fskDemod_M = comm.FSKDemodulator(M,freqSep,'BitOutput',true);

err = comm.ErrorRate;

modSignal = zeros((fskMod_M.SamplesPerSymbol*(length(data)/2)),1)+0i;

receivedData = zeros(length(data),1);

errorStats = zeros(3,1);

for counter = 1:10    
    modSignal = step(fskMod_M,data);    
    receivedData = step(fskDemod_M,modSignal);
    errorStats = step(err,data,receivedData);
end

end

In the above function, you can observe that I have both FSK modulation and Demodulation. I have no issues converting the modulation part into mex, but when it comes to demodulation it throws the following error:

I was successful in generating mex for just the modulation part, only when I include the demodulation part it fails. Kindly advise.

Also, I observed that,

class for FSK Modulation :

Whereas that of the demodulator is,

I have checked MATLAB documentation for comm.FSKDemodulator, it says it is supported for C code generation.

Your help will be greatly appreciated. Kindly advise

[Denis Gurchenkov]

This looks like a bug. Can you please attach all the files you have been using (the .m file and .prj file) and also specify what release of MATLAB you are using and what platform?

[mounika]

Hi Denis,

Couldn't attach the .prj file (It says unsupported format).

Attached the .m file and the test file

MATLAB 18b, Win64

Kindly suggest any other alternate way to do this code generation.

Also, does M-FSK modulator & demodulator block support code generation for C in Simulink

Answer 1

[Vivek Selvam]

Hi Mounika,

Code generation is successful when using Name-Value pairs for comm.FSKDemodulator as follows:

fskDemod_M = comm.FSKDemodulator('ModulationOrder',M,'FrequencySeparation',freqSep,'BitOutput',true);

The equivalent Simulink blocks (M-FSK Modulator Baseband and M-FSK Demodulator Baseband) support C code generation:

>> web(fullfile(docroot, 'comm/ref/mfskmodulatorbaseband.html'))
>> web(fullfile(docroot, 'comm/ref/mfskdemodulatorbaseband.html'))

Thanks for reporting this bug.

/Vivek

[mounika]

Thanks a lot Vivek. That solved my issue.

Best Regards,

Mounika