Low-Density Parity Check Code Concatenated with Generalized Partial Response Equalizer for High-Capacity Magneto-Optic Recording Channels

Abstract

In this study, we investigate the application of advanced coding and signal processing techniques for a magneto-optical (MO) disk system in order to improve its recording capacity. In particular, we study the application of low-density parity check (LDPC) codes with iterative soft decoding to the center aperture detection magneto-optical (CAD-MO) recording channel. The channel pulse response is identified from the read-back signals using the least mean squares (LMS) algorithm. The minimum mean-squared error (MMSE) technique was used to design appropriate generalized partial response (GPR) targets. LDPC encoded data are written onto and digitized read back signals are collected from a spin stand. Off-line numerical evaluations show that LDPC code concatenated with a channel detector matched to the GPR target can increase the capacity.