Modeling, detection, and LDPC codes for bit-patterned media recording

In this paper, we present a thorough and comprehensive study for bit-patterned media recording (BPMR), from a signal processing and coding perspective. We first propose a recording-physics-based generic channel model for BPMR, which includes all the major characteristics and impairments of the system. It also provides a fair basis for the performance comparison of different coding and detection schemes. We further propose various channel algorithms and techniques for BPMR, including a two-dimensional (2D) equalization scheme with one-dimensional (1D) generalized partial response (GPR) target to mitigate inter-track interference (ITI) and media noise, a maximum a posteriori (MAP) detector for BPMR with write errors, various low-density parity-check (LDPC) codes, as well as the iterative detection and decoding schemes. The corresponding performance gains are illustrated at 4Tb/in².