Patent ID: 7206993

Claim:
A method for decoding a received word made of one of a Reed-Solomon code and an extended Reed-Solomon code having a certain number of error corrections as input data, the decoding method comprising: a first error correction step of perform in error correction for the input data using an error locator polynomial and an error evaluator polynomial derived based on the input data and syndromes of the number of error corrections, and setting the result of error correction as first corrected data; a syndrome computation step of computing syndromes of the first corrected data; a second error correction step of performing error correction for the first corrected data based on the syndromes computed in the syndrome computation step, and setting the result of error correction as second corrected data; an error number estimation step of estimating the number of errors generated in the input data based on the syndromes of the input data; and an error number computation step of computing the number of errors using the error locator polynomial and the error evaluator polynomial derived based on the syndromes of the input data and the number of error corrections, wherein in the first error correction step, the error correction is performed for the input data using the number of errors estimated in the error number estimation step and the number of errors computed in the error number computation step.