Spatially-coupled LDPC coding in cooperative wireless networks

This paper proposes a new technique of spatially-coupled low-density parity-check (SC-LDPC) code-based soft information relaying scheme for a two-way relay system. We introduce an optimized SC-LDPC codes in relay channels. A more precise model is proposed to characterize the soft noise on the soft symbols, using a pre-calculated look-up table at the destination. This requires less signalling overhead compared to existing soft noise modelling techniques. We also introduce a variance correction factor to provide a rectification to the equivalent total noise variance at the destination. Finally, we modify the LLR former at the destination which is tailored to the proposed soft information relaying technique. Simulation results demonstrate that the proposed relay protocol yields an improved BER performance compared to competitive schemes proposed in the literature.