Construction of irregular protograph-based LDPC convolutional codes with windowed decoding

Abstract

Latency is an important indicator for modern communication systems. The windowed decoding scheme exhibits good performance with reduced latency. In this paper, a construction scheme for irregular protograph-based low-density parity-check (LDPC) convolutional codes with windowed decoding is proposed. The protograph-EXIT (P-EXIT) analysis for the accumulate-repeat-by-4-jagged-accumulate (AR4JA)-based LDPC convolutional codes over the additive white Gaussian noise (AWGN) channel shows that this flexible construction technique can give rise to the LDPC convolutional codes with different code rates and thresholds close to capacity, for both BP decoding and windowed decoding. The computer simulations identify the AR4JA-based LDPC convolutional codes outperform the regular LDPC convolutional codes and the AR4JA-based LDPC convolutional codes exhibit good performance with at least 56.7% reduced latency. Combining the proposed construction scheme for irregular protograph-based LDPC convolutional codes and the windowed decoding scheme can provide an efficient way to trade-off the decoding latency and the code performance.