Construction of Rate-Compatible Physical Layer Network Coding in Two-Way Relay Systems

The existing physical-layer network coding (PNC) only considers channel codes of a constant coding rate. In this paper, we propose a rate-compatible (RC) channel coding scheme for PNC in two-way relay systems. Our contributions are as follows. First, we propose a two-edge-type-low-density-paritycheck-aided PNC (JTNC) scheme due to its simple implementation and excellent performance. Second, we design an RC scheme, i.e., choice of locations and symbols, for the proposed JTNC in the relay. The simulation results show that the proposed RC-JTNC has good error correction performance and achieves large gains over the existing puncturing algorithms aided PNC over a wide range of rates.