Energy efficient resource allocation for D2D communication underlaying cellular networks

We consider the problem of resource sharing in Device-to-Device (D2D) communication underlaying cellular networks. The problem is formulated as a non-cooperative game in which mobile users, either legacy cellular users or D2D users, decide their respective transmission power over available resource blocks (RBs) with the goal of maximizing their own utility function. The key factor that distinguishes our work from the existing literature is the design of the utility function; the utility function of each user is defined as the achievable rate normalized by the power consumption, which is in [bits/sec/Joule]. Such a utility function well reflects the users´ satisfaction in reality when users are mobile and subject to the availability of energy due to the finite battery capacity and limited recharging facility. The scenario where the cellular and the D2D connections share the same resources is considered, in which the interference management between cellular and D2D communications is of great importance to guarantee the performance of high-priority cellular users. The most energy efficient strategy turns out that a DUE allocates the least amount of power on the channel with the best channel gain-to-interference-plus-noise-ratio (CINR) yet still achieves the highest data rate on that channel while a CUE allocates the optimal power on its assigned channel to reach the maximum energy efficiency.