Mode selection for device-to-device communications with Voronoi tessellation

Due to the increasing demand for local wireless transmissions from proximity-based social or local-content sharing applications, direct communication between user equipment (UE), known as device-to-device (D2D) communication, is regarded as a key technology component in LTE-Advanced. Taking the advantages of short transmission distance, D2D transmission increases resource utilization as well as reduces transmission delay and power consumption. However, the introduction of D2D communication incurs extra interference to the UEs who make the traditional cellular connection with the base station (BS), which shall be carefully considered. This paper, therefore, investigates the very beginning and fundamental problem in D2D communications underlaying cellular network, that is, either establishing local D2D communications or make a traditional communication with BS. A novel mode selection mechanism is proposed to control the number of UEs performing D2D communications to achieve maximum average transmit data rate. We apply the recent innovation, stochastic geometry, to analyze the performance of the proposed mode selection mechanism. By including the realistic feature in cellular network, that is, UEs will associate the closet BS, a Poisson-Voronoi tessellation is comprised. We further derive a tractable result on tradeoff between link reliability and data rate. As a result, this work serves as a powerful and efficient tool for analyzing the effects of D2D mode selection.