Construction of LDPC codes based on narrow-sense-primitive BCH codes

In this paper, we present an algebraic method for constructing regular low-density parity-check (LDPC) codes based on narrow-sense-primitive BCH codes. The construction method results in a class of high rate LDPC codes in Gallager´s original form. Codes in this class are free of cycles of length 4 in their Tanner graph and have good minimum distances. They can perform well with the iterative decoding. Also, proposed algebra LDPC codes can be designed for a new class of irregular codes based on a semi-algebraic structure for various code rates. It is shown that, with the proposed construction algorithms, fast construction time and reduced memory without the performance degradation can be achieved.