Statistical Modeling of the Physical-Layer Network Coding in Time-Varying Two-Way Relay Channels

Recent studies have shown that network coding (NC) directly applied at the physical layer -physical layer network coding (PLNC)- is a promising technique for two-way relay channels (TWRC). Unfortunately, to date, most existing PLNC works have mainly addressed cases of time-invariant channels rather than more realistic multipath time-varying wireless channels. To make further progress in understanding how to optimally implement and design PLNC techniques, we present in this paper, a simple but efficient equivalent interference channel (EIC) model for time-varying TWRC in the flat fading condition. The model captures important parameters such as the phase difference due to the asymmetry of the TWRC in real environment. Based on the EIC model, we derive and analyze some important analytical expressions for the statistical properties of the processes that describe the fading at the different stages of the PLNC in TWRC.