Performance improvement of G.hn system based on bit mapping technique

A new specification for power line communication (PLC), named G.hn, has been developed recently for the existing-wire home networking. G.hn system specifies a coded modulation scheme based on quasi-cyclic low-density parity-check (QC-LDPC) codes and quadrature amplitude modulations (QAMs). In this paper, we present a bit mapping strategy to exploit the unequal error protection (UEP) property inherent in the irregular LDPC codes and high-order constellations, which can effectively improve the reliability of the whole coded modulation system with no penalty. The method to design the bit mapping scheme is also investigated via the analysis of extrinsic information transfer (EXIT) charts. Simulation results reveal that the appropriate bit mapping scheme can achieve considerable gains in the G.hn system.