Efficiently Encodable Irregular QC-LDPC Codes Constructed from Self-Reciprocal Generator Polynomials of MDS Codes

This letter presents a class of quasi-cyclic (QC) low-density parity-check (LDPC) codes which are efficiently encodable and have better memory efficiency than other randomly constructed QC-LDPC codes. The parity-check matrix of the codes is obtained from a block circulant matrix that is generated from a self-reciprocal generator polynomial of a maximum distance separable (MDS) code by replacing some of its block entries by all zero matrices. We show by simulations that the codes can achieve excellent error performance.