Algebraic constructions of quasi-cyclic LDPC codes based on generators

This paper puts forward two novel algebraic construction of quasi-cyclic low-density parity-check(QC-LDPC) codes. The two constructions are achieved on multiplicative and additive matrix dispersions of two specified base matrices, which are constructed based on multiplicative and cyclic groups, respectively. In addition, making technique in code construction can also be applied to the two constructions. Simulation results show that codes generated in this paper perform well with iterative decoding over AWGN channel. The codes have advantages over Maykay codes in some aspects of code performances. Meanwhile, a code constructed in this paper converges very fast in iterative decoding, which is an important property in high throughput communication system.