Graph-based detection and reduced-complexity LDPC decoding over 2D intersymbol interference channels

In this paper, we propose a fully graph-based iterative detection and decoding scheme for low-density parity-check (LDPC) coded generalized two-dimensional (2D) intersymbol interference (ISI) channels. The 2D detector consists of a downtrack detector based on the symbol-level sum-product algorithm (SPA) and a bit-level SPA-based crosstrack detector. A LDPC decoder based on simplified check node operations is used to provide soft information for the 2D channel detector. Numerical results show that the proposed receiver significantly reduces the decoding complexity and also achieves better performance as compared with the trellis-based BCJR detector over 2×2 2D channels.