Low-density parity-check (ldpc) codes from affine permutation matrices, called apm-ldpccodes, are a class of ldpccodes whose parity-check matrices consist of zero matrices or apms of the same orders. apm-ldpccodes ...
详细信息
Low-density parity-check (ldpc) codes from affine permutation matrices, called apm-ldpccodes, are a class of ldpccodes whose parity-check matrices consist of zero matrices or apms of the same orders. apm-ldpccodes are not quasi-cyclic (QC), in general. In this study, necessary and sufficient conditions are provided for an apm-ldpccode to have cycles of length 2l, l 2, and a deterministic algorithm is given to generate apm-ldpccodes with a given girth. Unlike Type-I conventional QC-ldpccodes, the constructed (J, L) apm-ldpccodes with the J x L all-one base matrix can achieve minimum distance greater than (J + 1)! and girth larger than 12. Moreover, the lengths of the constructed apm-ldpccodes, in some cases, are smaller than the best known lengths reported for QC-ldpccodes with the same base matrices. Another significant advantage of the constructed apm-ldpccodes is that they have remarkably fewer cycle multiplicities compared with QC-ldpccodes with the same base matrices and the same lengths. Simulation results show that the binary and non-binary constructed apm-ldpccodes with lower girth outperform QC-ldpccodes with larger girth.
暂无评论