Design of LDPC Codes for Unequal ISI Channels

In this paper, we design an irregular low-density parity-check (LDPC) codes for unequal inter-symbol interference channels based on the modified extrinsic information transfer chart. During transmission, each LDPC codeword will be divided and transmitted to the different channels. The aim of this scheme is to avoid transmitting the whole codeword in a high error rate channel. The simulation results show that the proposed code optimized for both PR! and PR2 channels can achieve a 0.2 coding gain over the codes designed specifically for each individual channel. When this simple code is applied to a perpendicular channel with these two targets, the coding gains of the proposed code is about 0.08 dB at the frame error rate of 10
^-3
.