Joint Equalization and Decoding for Nonlinear Two-Dimensional Intersymbol Interference Channels with Application to Optical Storage

Abstract

An algorithm that performs joint equalization and decoding for nonlinear two-dimensional intersymbol interference channels is presented. The algorithm performs sum-product message-passing on a factor graph that represents the underlying system. The two-dimensional optical storage (TWODOS) technology is an example of a system with nonlinear two-dimensional intersymbol interference. Simulations for the nonlinear channel model of TWODOS show significant improvement in performance over uncoded performance. Noise tolerance thresholds for the algorithm for the TWODOS channel, computed using density evolution, are also presented and accurately predict the limiting performance of the algorithm as the codeword length increases.