Outage Probability Analysis and Power Allocation for Two-Way Relay Networks with User Selection and Outdated Channel State Information

This paper considers a multiuser two-way relay network (TWRN) consisting of one base station (BS), one amplify-and-forward (AF) relay and K mobile stations (MSs) among which the Nth-best MS is selected to exchange information with the BS. Specifically, we study the impact of outdated channel state information (CSI) on the system over time-varying Rayleigh block-fading channels by deriving a tight closed-form lower bound for the outage probability. We also obtain an asymptotic outage probability expression for high signal-to-noise ratio (SNR). Moreover, by minimizing the asymptotic outage probability, we optimize the power allocation (PA) among the network nodes. Numerical and simulation results collaborate the proposed studies.