Power Optimization of Device-to-Device Communication Underlaying Cellular Communication

We address resource sharing of the cellular network and a device-to-device (D2D) underlay communication assuming that the cellular network has control over the transmit power and the radio resources of D2D links. We show that by proper power control, the interference between two services can be coordinated to benefit the overall performance. In addition, we consider a scenario with prioritized cellular communication and an upper limit on the maximum transmission rate of all links. We derive the optimum power allocation for the considered resource sharing modes. The results show that cellular service can be effectively guaranteed while having a comparable sum rate with a none power control case in most of the cell area.