A New Class of Irregular Low-Density Parity-Check Codes With Linear Encoding Complexity

In this paper we propose a new class of irregular low-density parity check (LDPC) codes with linear encoding complexity. We show that these codes offer performances compatible with irregular LDPC codes with randomly generated parity-check matrices. The non-systematic part of the paritycheck matrix has a simple triangular structure, which enables linear encoding, while the systematic part of the matrix can be generated randomly. We show that the construction of the parity-check matrix also has linear complexity. Simulation results reveals that the proposed coding scheme outperform LDPC codes with randomly generated parity-check matrix at low-BER regions. The proposed scheme can also be seen as a variant of a number of known generalized irregular repeat-accumulate codes (IRA), but with certain advantages.