Joint detection and decoding for physical-layer network coding in power line channel

In this study, a joint detection and generalised sum-product decoding algorithm for a two-way relay physical-layer network coding (PLNC) system in power line communication is proposed. Distinct from the existing works which mainly focused on separate or iterative PLNC detection and decoding, the proposed algorithm is a belief propagation-based joint PLNC detection and decoding algorithm, which integrates the PLNC, symbol detector and channel decoder together. The proposed algorithm is described by a joint factor graph, in which the detection nodes are connected to the factor graph of a generalised sum-product decoder. The PLNC demodulation is redesigned to make sure that the degree of each detection node in the joint factor graph is more than one. A low computational complexity solution of the proposed joint decoding algorithm based on the majority-logic algorithm is also proposed. The simulation results reveal the validity of the proposed algorithms.