Short-block LDPC codes design with semi-random parity-check matrix

In this paper, we propose a design method for short block length low-density parity-check (LDPC) codes which use the structure of semi-random parity-check matrix and the optimal degree distribution pairs derived from density evolution algorithm. Simulation results show that the bit error performance of the designed code is better than Turbo codes with the same block length and code rate when Signal Noise Ratio (SNR) exceeds 2.5dB. At the same time, the complexity of decoder is lower than that of Turbo codes. This design method provides guiding significance for choosing an error-correcting code for reliable communication in narrow-band channel.