Ergodic rate analysis for multi-pair two-way relay large-scale antenna system

A multi-pair two-way relay system sharing with a single relay with large numbers of antennas is considered. In this paper, we investigate the ergodic achievable rates when maximum ratio combining/maximum ratio transmission is used at the relay station. The analytical results for the achievable rates are derived and the asymptotic analysis is conducted when the number of antennas, N, grows to infinity. Results demonstrate a number of phenomena including the logarithmic increase of the average rates with the number of antennas, and the logarithmic decrease of the average rates with the number of interference pairs, K-1, when the transmit power of both relay and users are fixed.