The Proposed Simplified Iterative Decoding for 2D-ISI Magnetic Recording Channels

2D inter-symbol-interference (2D-ISI) channel models ultra-high-density magnetic recording systems, which suffer from ISI in the down track direction and inter-tack interference along the cross-track direction. These interferences seriously degrade the performance of the magnetic recording systems. Low-density parity check (LDPC) codes was used in storage systems However, although non-binary LDPC codes with log-BP decoding was designed for 2D-ISI channels, it has a drawback of a high decoding complexity. To address this issue, this paper proposes a simplified iterative decoding for 2D-ISI channels. In specific, we use extended min-sum (EMS) decoding with truncation of messages to simplify computation and optimize scale factor in outer iteration by the EXIT analysis to improve the performance. Finally, the simulated results show that the proposed scheme with reduced complexity for 2D-ISI system can maintain an approximate performance to traditional one. Even at high SNR regions, the proposed scheme will be better than previously decoding algorithm.