A QC-LDPC construction algorithm for increasing the throughput of layered decoders

Pipelined layered decoder (PLD) of quasi-cyclic low-density parity-check (QC-LDPC) codes is one of most popular high-throughput decoder in modern communication systems. However, the traditional QC-LDPC codes are not suitable for PLD and lead to memory access conflict problems (MACPs) that reduce the throughput of PLD. Therefore, an efficient layered block progressive edge-growth (EL-BPEG) algorithm is proposed to construct a class of QC-LDPC codes that can avoid MACPs and increase throughput. EL-BPEG appends check nodes, rather than variable nodes, progressively into Tanner Graph with strict concentrated check-node degrees. And it establishes edges according to the latency of the pipelines in PLD; thus, all idle clocks can be eliminated for the PLD with EL-BPEG codes. Result indicates that the throughput of PLD can be improved by 50.2% to 99.2% by using the EL-BPEG codes compared with the traditional QC-LDPC codes. Simulations show that the error performances of EL-BPEG codes are as well as the codes in standards.