Energy-Efficient Mode Selection for D2D Communications in Cellular Networks

One of the major challenges to the performance of device-to-device (D2D) communications co-existing with cellular links lies in the interference management. Mode selection has been recognized as the most effective means to deal with this challenge. In this paper, we explore the mode selection for D2D communications underlaying cellular networks from an energy-efficient perspective. Through stratifying the transmit power, we analyze the success probability and ergodic capacity for both cellular and D2D links using stochastic geometry. On the basis of analysis, two energy-efficient mode selection mechanisms are devised. Our simulations show that D2D users are able to select appropriate modes via our developed mechanisms. In particular, an interesting insight is obtained: when the required signal-to-interference ratio is guaranteed, the success probability of cellular users who are far away from the base station is slightly greater than that who are close to the base station. This insight is expected to provide a design guideline for D2D mode selections.