Power allocation for two-way relay channel in wireless bidirectional networks

In this paper, we consider a two-way relay channel (TWRC) network model in wireless bidirectional network, where end nodes have the full channel-state information (CSI) and relay nodes only have the channel-amplitude information (CAI). Our objective is to minimize the transmission power under the condition that the required transmission rates are satisfied. Different from previous works which assume no direct transmission paths exist between the source and destination nodes due to high shadow fading or large separation, we propose energy efficient power allocation methods for both analog network coding (ANC) and time division broadcasting (TDBC) schemes, and the closed-form expressions of optimal power allocation schemes are derived. Simulation results demonstrate the energy efficiency of the ANC and TDBC based power allocation methods comparing with other transmission schemes.