Interference-mitigation based antenna selection scheme in device-to-device communication underlaying cellular networks

This paper investigates an antenna selection scheme performing interference mitigation in device-to-device (D2D) communication underlaying cellular networks. Exact closed-form expression of the ergodic achievable rate is derived. Based on this result, the analysis in the high SNR regime at the base station (BS) and the scenario with very large antenna number are investigated, which indicate the saturation of the ergodic achievable rate when these parameters grow very large. Next, two approximations are then shown to be fairly tight, thus yielding much simpler expression of the ergodic achievable rate. Furthermore, we provide the performance analyses in the small cell and macro cell respectively and show that in the small cell, the high SNR approximation of the ergodic achievable rate varies proportionally with the transmit power ratio between the BS and the D2D transmitter. In the macro cell setting where the pathloss factor between the D2D terminals becomes much larger, we show that the ergodic achievable rate´s improvement potentials by increasing the antenna number can be elevated with higher transmit power at the BS. Numerical results are then provided to verify the correctness of the expressions derived above. Some observations are made accordingly.