Outage Probability and Relay Selection in Bidirectional AF Relay Networks

We study bidirectional amplify-and-forward (AF) relaying network consisting of two end-terminals and multiple relays, where each node operates in a half- duplex mode. A best relay is selected from multiple relays in a distributed manner to help communication between two end-terminals. Specifically, we first consider relay selection (RS) scheme for bidirectional AF relay network based on a max-min criterion to maximize the information rate and to minimize the outage probability. Then based on this RS scheme, we derived the close form expression of outage probability. From numerical and observations, we see that the proposed RS scheme gives better outage performance than random relay selection scheme and equal power multiple-relay scheme in symmetric as well as in asymmetric channels.