Symbol and Bit Mapping Optimization for Physical-Layer Network Coding with Pulse Amplitude Modulation
In this paper, the authors consider a two-way relay network in which two users exchange messages through a single relay using a Physical-layer Network Coding (PNC) based protocol. The protocol comprises two phases of communication. In the Multiple Access (MA) phase, two users transmit their modulated signals concurrently to the relay, and in the BroadCast (BC) phase, the relay broadcasts a network-coded (denoised) signal to both users. Non-binary and binary network codes are considered for uniform and non-uniform Pulse Amplitude Modulation (PAM) adopted in the MA phase, respectively.