MATLAB: How to discern if the codeword being sent in the C code is correctable

Question

I have written a function in MATLAB that creates a comm.RSDecoder object. I generate C code for this function and want to find out if the codeword being sent in the C code is correctable. Also, which variable should I look at to get this information?

Answer 1

The step() method of "comm.RSDecoder" has an optional second output (please refer to the first link below), which returns the number of corrected errors. If there is a decoding failure, "-1" will be returned in this ERR output argument. A "-1" value of this output indicates that the codeword is not correctable. This is explained in the details of the "NumCorrectedErrorsOutputPort" property in both the links below:

http://www.mathworks.com/help/comm/ref/comm.bchdecoder.step.html

http://www.mathworks.com/help/comm/ref/comm.rsdecoder-system-object.html

You need to change your step() call and specify this second output. For example:

>> [msg, numErr] = step(dec,codeword);

Then generate the C code and track down the C variable that corresponds to the "numErr" MATLAB variable.