Fast BCH error detection and correction using generator polynomial permutation

Abstract

Methods and apparatus for cyclic code codeword creation, error detection, and error correction are disclosed. The methods and apparatus utilize a set of permuted generator polynomials, each representing shifted and exclusive-ored (XORed) versions of the cyclic code generator polynomial according to a specific input bit pattern. The permuted generator polynomial may be provided by look-up table, hardware, or a software equivalent of this hardware. Use of the permuted generator polynomial greatly reduces the number of calculations required to calculate syndromes and trap errors in codewords. The permuted generator polynomial can be used to replace m iterations of a polynomial division operation with a single XOR operation. The bit pattern used to select a permuted generator polynomial is derived from the m high-order bits of the dividend at each step. Using the disclosed embodiments, the number of clock cycles or instruction cycles required to perform cyclic code computations can be significantly reduced for both hardware and software implementations.

Dependencies are inferred from the claim text.