Interference cancellation in device-to-device communications underlying MU-MIMO cellular networks

This paper investigates the device-to-device (D2D) communication underlaying multi-user multi-input multi-output (MU-MIMO) cellular networks. It is assumed that D2D users reuse the downlink time-frequency resources of cellular links, and the base station (BS) is assumed to be equipped with multiple antennas. We investigate the ergodic achievable sum rate of the system when the interference cancellation (IC) pre-coding strategy is employed at the BS. The distributions of the received signal-to-interference-plus-noise ratio (SINR) for each link are firstly analyzed, and an exact ergodic achievable sum rate of the whole system with closed-form expressions is then derived. Furthermore, we present novel upper and lower bounds with simpler expressions, which are later verified to be fairly close to the Monte-Carlo simulations. All the expressions we presented are suitable for arbitrary network topology and arbitrary number of antennas at BS. Based on the derived bounds, the influence of the antennas at BS on system performance is then analyzed. We reveal that the system performance increases along with the number of antennas at BS in a logarithmic way. The accuracy of our analytical results is validated via comparisons with Monte-Carlo simulations.