A new LDPC decoding algorithm aided by segmented CRCs for erasure channels

This letter introduces a new low-density parity-check (LDPC) decoding algorithm that exploits the cyclic redundancy check (CRC) information of data segments. By using the error detection property of CRC, we can successively decode data segments in the codeword corrupted by magnetic recording channels. The key idea is that variable nodes corresponding to data segments with correct checksum are fixed to deterministic log likelihood ratio (LLR) values (or probabilities) during the LDPC iterative decoding. In this way, the performance regarding the decoding speed and codeword error rate can be improved without significant modification of the LDPC decoding structure. Moreover, the CRC information is also used for an early stopping criterion of LDPC decoding. Simulation results verify our claims.