Iterative decoding for partial response (PR), equalized,magneto-optical (MO) data storage channels

摘要

Turbo codes and low-density parity check (LDPC) codes withniterative decoding have received significant research attention becausenof their remarkable near-capacity performance for additive whitenGaussian noise (AWGN) channels. Previously, turbo code and LDPC codenvariants are being investigated as potential candidates for high-densitynmagnetic recording channels suffering from low signal-to-noise ratiosn(SNR). We address the application of turbo codes and LDPC codes tonmagneto-optical (MO) recording channels. Our results focus on a varietynof practical MO storage channel aspects, including storage density,npartial response targets, the type of precoder used, and mark edgenjitter. Instead of focusing just on bit error rates (BER), we also studynthe block error statistics. Our results for MO storage channels indicatenthat turbo codes of rate 16/17 can achieve coding gains of 3-5 dB overnpartial response maximum likelihood (PRML) methods for a 10-4ntarget BER. Simulations also show that the performance of LDPC codes fornMO channels is comparable to that of turbo codes, while requiring lessncomputational complexity. Both LDPC codes and turbo codes with iterativendecoding are seen to be robust to mark edge jitter