Impact of Imperfect Channel State Information on Bi-Directional Communications With Relay Selection

In this correspondence, we study the effect of channel estimation error to the reception reliability for decode-forward based two-way relaying and physical layer network coding. In particular, we focus on the scenario where the channel estimation error is inversely proportional to signal-to-noise ratio (SNR). To such a scenario, analytic results have been developed to show that symbol error probability can approach zero by increasing SNR and extra diversity gains can still be achieved by applying relay selection.