Fairness-Aware Energy-Efficient Resource Allocation in D2D Communication Networks

In this paper, the energy efficiency in a cellular network with device-to-device communications is studied from user fairness perspective. A mixed-integer max-min optimization problem is formulated, in which both mode selection and resource allocation are considered. Since the optimal solution requires exhaustive search, which is NP-hard, two suboptimal methods are derived. First, a Lagrangian decomposition-based method is proposed to jointly solve subcarrier assignment and power allocation with integer constraint relaxation under different modes. To further reduce the computational complexity, a low-complexity decomposition (LCD) method is derived. A novel mode selection scheme, a subcarrier assignment scheme, a power allocation scheme, and a mode switching scheme are introduced and analyzed. The LCD method is scalable and suitable for a large number of devices and subcarriers. Simulation results demonstrate that our proposed suboptimal methods achieve satisfactory energy efficiency performance and promote the fairness among individual users.