In order to solve high encoding complexities of irregu-lar low-density parity-check (LDPC) codes, a deterministic con-struction of irregular LDPC codes with low encoding complexities is proposed. The encoding algorithms are designed, whose com-plexities are linear equations of code length. The construction and encoding algorithms are derived from the effectively encoding characteristics of repeat-accumulate (RA) codes and masking technique. First, the new construction modifies parity-check ma-trices of RA codes to eliminate error floors of RA codes. Second, the new constructed parity-check matrices are based on Vander-monde matrices; this deterministic algebraic structure is easy for hardware implementation. Theoretic analysis and experimental results show that, at a bit-error rate of 10 × 10- 4, the new codes with lower encoding complexities outperform Mackay's random LDPC codes by 0.4-0.6 dB over an additive white Gauss noise (AWGN) channel.
展开▼
