On the outage performance of two-way amplify-and-forward relaying with outdated CSI over multiple relay network

Two-way relaying (TWR) has recently received a great deal of attention since it can recover the loss in spectral efficiency that characterizes conventional half-duplex transmission systems operating within cooperative networks. Additionally, when relay selection is considered in multiple relay network, outdated channel state information (CSI) due to feedback delays can create important challenges from a practical point of view. In this paper, we study the outage performance of an amplify-and-forward (AF)-based TWR system with multiple relays where a single relay selection is performed based on outdated CSI. Specifically, we consider a single relay selection scheme in AF-based TWR system under outdated CSI conditions and offer a statistical analysis of the signal-to-noise ratio per hop with the given policy. For the analysis of the outage probability with asymmetric outage thresholds, we offer an accurate closed-form approximation based on the provided statistical/joint statistical analyses of a dual-hop AF transmission. Finally, we verify our analytical results with some selected computer-based simulation results.