BCH code length must be 2^m -1 ??

[davyzhu]

Hello all,

Matlab supply the bchenc function, but it said the code length must be 2^m -1.
Could code length not equal to 2^m -1? Any suggestions will be appreciated!

Best regards,
Davy

 

[zorro]

Hi davyzhu,

The code length must be 2^m-1, but you can use a shortened code.
Shortening the code, an (n,k) code can be used as a (n-z,k-z) code (for any 0<z<k) with at least the same error-correction capability of the original code.
The idea is simple: look for shortened block codes on error control coding books.
Regards

Z