Implementation of encoder and decoder for LDPC codes based on FPGA

This paper proposes a parallel cyclic shift structure of address decoder to realize a high-throughput encoding and decoding method for irregular-quasi-cyclic low-density parity-check (IR-QC-LDPC) codes, with a dual-diagonal parity structure. A normalized min-sum algorithm (NMSA) is employed for decoding. The whole verification of the encoding and decoding algorithm is simulated with Matlab, and the code rates of 5/6 and 2/3 are selected respectively for the initial bit error ratio as 6% and 1.04%. Based on the results of simulation, multi-code rates are compatible with different basis matrices. Then the simulated algorithms of encoder and decoder are migrated and implemented on the field programmable gate array (FPGA). The 183.36 Mbps throughput of encoder and the average 27.85 Mbps decoding throughput with the initial bit error ratio 6% are realized based on FPGA.