Performance Analysis of Two-Way Relay Selection Scheme Based on ARDT Protocol

Adaptive Relay-Assisted/ Direct Transmission (ARDT) proposed in [13] is a simple and efficient protocol which adaptively utilizes the direct link between two sources with only channel state information at receiver (CSIR), and it validly enhances the spectrum efficiency of time division broadcast (TDBC) system. In this paper, we combine ARDT with joint power allocation and relay selection for multi-relay scenario. Each relay optimize its own forwarding power to maximize the minimum end to end signal to noise ratio (SNR) towards two sources, and the optimal relay is then selected to cooperate. System outage probability, average throughput and average bit error rate (BER) are analyzed with theoretical upper and lower bounds. Numerical simulations validate the rationality of bounds, and show that whether maximal ratio combining (MRC) is adopted for receiving makes little difference. The proposed relay selection scheme is verified to outperform that based on original TDBC in reference work.