A class of structured LDPC codes with large girth

A class of structured LDPC codes-turbo-structured LDPC (TS-LDPC) codes-composed of two subtrees connected by an interleaver is introduced in this paper. TS-LDPC codes with good girth properties are easy to design: careful design of the interleaver component prevents short cycles in its Tanner graph. A methodology to design TS-LDPC codes with arbitrary column weight j/spl ges/2 and arbitrary girth is also presented. In addition, a complexity reduced decoding algorithm is described. Simulation results demonstrate the good performance of TS-LDPC codes when compared to random LDPC codes of the similar size and rate.