Energy efficient power allocation for co-located antenna systems with D2D communication

This paper investigates the energy efficient resource allocation when adding dedicated device-to-device (D2D) communication in the co-located antenna systems (CAS). We consider the user equipments (UEs) are changing over time and the appropriate potential UEs to form D2D pairs are varying with time. Our optimization objective is to maximize the system's energy efficiency (EE) with the constraints of the maximum transmit power of UEs and D2D pairs in different total power consumption models. Firstly, an algorithm is developed to choose appropriate potential UEs to form D2D pairs in this paper. Then we exploit fractional programming method to obtain optimal energy efficient power allocation solutions. Simulation results are provided to demonstrate the effectiveness of the developed D2D pairs choosing algorithm and the power allocation algorithm.