Quasi Cyclic Low Density Parity Check Codes Based on Progressive Cycle Growth Algorithm
Short cycles in the Tanner graph of a given LDPC code has negative effect on the performance of iterative decoding. To improve the performance, we presented an approach for constructing Quasi Cyclic Low Density Parity Check (QC LDPC) codes whose associated Tanner graph has large girth and a small amount of short cycles. Each column block of the parity check matrix was designed by adding circulant permutation sub matrices one after another, provided the current parity check matrix has minimal number of short cycles. The condition for the proposed QC LDPC codes to have girth at least 6 was also analyzed. Regular and irregular QC LDPC codes with various lengths and rates can be constructed. Simulations show that the proposed QC LDPC codes have less short cycles and better performance than existing progressive edge growth based QC LDPC codes.
2016 Sixth International Conference on Instrumentation Measurement, Computer, Communication and Control (IMCCC)