Decoding for iterative Reed-Solomon coding schemes

For high density data storage systems channel errors may appear in the form of bursts. This error correlation can significantly degrade the bit error rate on the subsequent stages of data processing. To correct error bursts the interleaved Read-Solomon (RS) codes are used. Usually, after the deinterleaving, the received words are decoded one by one by the same error correction algorithm. In this paper, a novel approach for the decoding of interleaved codes is proposed. It is based on a notion of covering error locators that locate error positions in two or more adjacent words. To compute the covering error locator polynomial, a modification of the Berlekamp-Massey algorithm is proposed. It is shown that with a certain probability of failure the proposed algorithm can correct more errors than the designed error correction ability. The algorithm may also be useful in a more general case of interleaved coding schemes with both rows and columns encoded by RS code.