Performance Analysis of Joint Relay Selection and Power Allocation for Two-way Relay Channels

This paper investigated the outage probability bound of joint relay selection and power allocation for two-way relay channels (TWRC). The two transceivers exchanged information with the help of the relay during two time slots based on amplify-and- forward (AF). A tight lower bound of outage probability with optimal power allocation was derived. Based on the close-form outage probability bound, we proposed a simplified relay selection criterion, which just calculated harmonic mean of instantaneous channel gains. Simulation verifies the theoretical analysis we proposed. The lower bound we proposed is tight comparing with actual performance for all signal-to-noise ratio (SNR) range, meanwhile more accurate than any existing bound. Index Terms - Two-way relay, outage probability, Amplify-and- Forward, joint relay selection and power allocation