A distributed joint power control and mode selection scheme for D2D communication underlaying LTE-A networks

In addition to providing high data rate, Device-to-Device (D2D) communication reduces the transmit power of users and improve spatial spectrum reuse significantly. In this paper, we formulate the joint power control and mode selection problem for D2D communications underlaying LTE-A network for minimizing the aggregate transmit power of users subject to a minimum target throughput for each cellular and D2D user, and propose a distributed joint mode selection and power control scheme for addressing it. In our proposed distributed scheme, each D2D user selects its mode on each of its assigned resource blocks (RBs), based on the effective interference on that RB, and each cellular and D2D user adjusts its transmit power level on its assigned RBs so that its target throughput is achieved. The mode selection by D2D users and the power control by cellular and D2D users in our proposed scheme are performed in an iterative manner. The simulation results demonstrate the effectiveness and superiority of our proposed method over two extreme methods (i.e., force D2D and force cellular methods), in terms of power consumption.