Efficiency of short LDPC codes combined with long Reed-Solomon codes for magnetic recording channels

This paper proposes the use of low-density parity check (LDPC) codes with short block lengths such as 1-K bits for magnetic recording. In general, there is a degradation in bit error rate as the block length of the LDPC codes decreases. Yet, we show that short LDPC codes do not suffer from degraded sector-error-rate performance if the sector size is 32 K bits and if long Reed-Solomon codes over GF(2¹²) are used. This is due to the unique error distribution of iterative decoding. Shorter codes significantly reduce the amount of buffer memory in the iterative decoder and make hardware implementation more feasible.