Finite-length EXIT analysis for protograph-coded two-dimensional ISI channels

In this paper, we consider the protograph low-density parity-check (LDPC) codes in two-dimensional inter two-dimensional (2D) intersymbol interference (ISI) channels, which are widely used in modeling ultra-high-density magnetic recoding systems. In particular, we study the convergence and error performance of protograph codes over 2D-ISI channels. We modify the finite-length (FL) extrinsic information transfer (EXIT) algorithm for the sake of facilitating the convergence analysis of protograph codes. Through the FL-EXIT analyses and simulated results, we observe that the regular column-weight-3 (CW-3) code is superior to the protograph codes optimized for one-dimensional (1D) ISI channels, e.g., the 1D-ISI protograph code. Accordingly, the 1D-ISI protograph code may not be served as a good candidate for use in ultra-high-density data storage systems.