We consider the use of high-rate low-density parity-check (LDPC) codes for magnetic recording. We design and evaluate the performance of a magnetic recording system, which uses an LDPC code as the error-correcting code, in conjunction with a rate 16/17 quasimaximum-transition-run (QMTR) channel code on a modified E/sup 2/PR4 (ME/sup 2/PR4)-equalized channel. Iterative decoding between the partial response channel and the LDPC code is performed. Simulations show that an additional four-dB gain over the QMTR code can be obtained by the LDPC code. The algorithms used to design this LDPC code are also discussed.

Block turbo codes have been shown to have near-optimum performance and lower decoding complexity than convolutional turbo codes for additive white Gaussian noise (AWGN) channels. In this paper we discuss the applicability of block turbo codes to partial-response (PR) equalized Lorentzian channels for magnetic recording. In particular, we consider the iterative decoding of product codes and parallel concatenated block codes. Simulation results show that both systems offer substantial gains over uncoded systems.