An Encoder Design for Layered Approx-Regular LDPC Codes

A construction method and an encoder design scheme for layered approx-regular low-density-parity-check (LAR-LDPC) codes were proposed. Although based on the existing Richardson-Urbanke (RU) algorithm, the new scheme entirely removes the forward substitution (FS) operation and handles the dense-matrix-vector multiplication using cyclic shift registers. This decreases the hardware complexity from linearity to the square of the dimension of dense matrix to linearity only to the dimension of dense matrix. Compared with RU algorithm, the new scheme reduces the encoding latency and improves the throughput, and features high flexibility of online reconfiguration in both code length and code rate. The simulation result shows that LAR-LDPC codes closely approach randomly constructed regular LDPC codes in terms of error correction performance, thus enjoying a fairly high referential merit in practical application.