Relay selection with analog network coding in bidirectional networks

We study relay selection (RS) with the analog network coding (ANC), which is an amplify-and-forward (AF)-based protocol in bidirectional relay networks. We consider a bidirectional network consisting of two different end-sources and multiple relays, where each terminal has a single antenna and operates in a half-duplex mode. In this network, a single best relay is selected depending on channel conditions to help bidirectional communication between the two end-sources. Specifically, we first consider an RS scheme for the ANC protocol based on a max-min criterion to minimize the outage probability. Then we derive a closed-form outage probability. Numerical results confirm that the closed-form expression of the ANC protocol is very accurate.