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CCSDS Reed-solomon decoding- error evaluation

Started by Raju_srk August 6, 2010
Hi,
I'm making a CCSDS reed-solomon decoder.
I'm using the C code as written by Simon Rockliff (1991) as a starting
point.
The main feature of the CCSDS specification is that it uses alpha^11 as
primitive element and generator polynomial roots are : alpha^(128-E) to
alpha^(127+E), which makes the problem unusual.
In the above C code, by changing the generator polynomial and using the
roots of gen polynomial to calculate syndromes, and by evaluating the error
locator polynomial at powers of (alpha^11) rather than alpha(as usually is
the case), Im able to correctly decode the error locations.
Now, can you provide any help regarding how to find error value? Please
suggest any modifications in error evaluation step of the decoding
algorithm, in the light of the unique features of the CCSDS specification.