Linear Detection and Precoding for Physical Network Coding in Two-Way MIMO Relay Channels

We investigate linear detection and precoding for denoising-based physical network coding (D-PNC) in two-way multi-input multi-output relay channels. We propose an MMSE-based detector, which first gives a coarse detection to the two source messages using MMSE detector and then detects the product of the two coarse detected messages. The advantage of such detector is to randomize the interference. A simple precoder is also proposed for relay message transmission, which provides fairness. Simulation results show that D-PNC with the proposed detector and precoder has similar pair error rate performance to other schemes while keeps simple structure and lower complexity.