A novel IRA-like codes construction method based on cyclic matrix permutation

Due to the structure limitation of navigation message, the channel coding used by the satellite navigation system should have as high a coding gain as possible under short code lengths. At the same time, in order to reduce the cost of the receiver, the channel coding suitable for the navigation system should have the lowest complexity for coding and decoding. A well-designed structured LDPC code can reduce the complexity of the codec significantly without the loss of performance. In this paper, a method based on cyclic matrix permutation is proposed to improve IRA-like codes, which is combined Irregular Repeat Accumulation Codes (IRA) with Quasi-Cyclic LDPC codes. Simulation results show our method has good iterative decoding performance in decreasing bit error rate and greatly reducing the number of iterations required for decoding as well as error platform.