Performance Analysis of User Selection for Multiuser Two-Way Amplify-and-Forward Relay

This paper considers a multiuser two-way relay channel (MU-TWRC) in which a base-station and a selected mobile-station (MS) among K number of MSs exchange messages during two time slots with the help of a half-duplex amplify-and-forward relay. We analyze the performances of a MU-TWRC. The closed-form expressions of the lower bound of the average rates are derived. The asymptotic expressions of the average rates are also analyzed in the limit of large K. Analysis and simulation results indicate that the former matches well to the latter, and the performance of a MU-TWRC can increase as K increases or be bounded to some constant according to the channel conditions.