Concatenated error correction coding for high-order PRML channels

A modified E/sup 2/PRML (ME/sup 2/PRML) channel is optimized for high-density magnetic recording in order to reduce long error-propagation events in an ML detector. A cyclic redundancy-check error-correction code (CRCC), an innerblock ECC concatenated to the ML detector, is introduced as a new ECC-coding scheme for the high-order partial response maximum likelihood (PRML) channel. The CRCC coding can efficiently improve the BER performance with only a few redundant check-bits which intensively correct most-dominant short error-events in the ME/sup 2/PRML detector. A 16/17 coded ME/sup 2/PRML channel in conjunction with a 2.9% redundant CRCC coding can achieve a gain of more than 35 dB over a conventional 16/17 coded EPRML channel at a user density of 2.8.