Additive encoding low-density parity-check (AE-LDPC) codes for two-dimensional magnetic recording (TDMR)

Abstract

In this paper, a novel coding with side information at the encoder (CSIE) scheme is developed for two-dimensional magnetic recording (TDMR) channel. The write errors in the TDMR channel are modeled with random Voronoi grains, and the encoder uses the grain states as side information for additive encoding (AE) of the codewords of a low-density parity-check (LDPC) code. Getting the complete side information about all the grain states for encoding may be impractical because of the large number of read-after-write tests required. As a more practical alternative, coding with partial side information is also investigated with the AE-LDPC coding scheme, where partial side information can be extracted from the distribution of the grains instead of read-after-write tests. The proposed coding schemes are evaluated by numerical simulations using an idealized TDMR channel model. Simulation results show that the AE-LDPC provides an improved customer density with a sufficient reliability.