Low-complexity high-rate irregular QC-LDPC codes with applications to PR2 and EPR2 channels.

ABSTRACT In this paper, we propose a modified high rate (3, L) quasi-cyclic low-density parity-check (QC-LDPC) code based on circulant permutation matrices for efficient encoder implementation. The structure of the code is modified from a (3, L) regular QC-LDPC code to be an approximate lower triangular matrix and a linear independent form. We present two novel efficient encoding techniques for generating redundant parity bits. The complexity of the encoder implementation depends on the number of redundant parity bits of the code for one-stage encoding and the length of the code for two-stage encoding. The advantage of both encoding techniques is that few XOR gates are used in encoder implementation. The simulation results show that the proposed codes at code rate 0.884 and 0.953 have good bit error rate performance compared with other LDPC codes over PR2 and EPR2 channels. European Transactions on Telecommunications. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]