Resource Allocation for D2D Underlay Communications With Proportional Fairness Using Iterative-Based Approach

In this paper, we develop a novel resource allocation scheme that aims to improve the system fairness, with minimum SINR (Signal to Interference and Noise Ratio) constraints and power limits for the Device-to-Device (D2D) underlay communications. Since the evaluation of the system fairness is different for t = 1 and t ≥ 2, where t is the scheduling period, we divide our joint optimization problem into two cases: t = 1 and t ≥ 2. For each case, we decompose the joint optimization problem into two subproblems: power and channel allocations. We then propose the corresponding power allocation algorithm for each case. By introducing virtual D2D links, we model the channel allocation as a 3-D (3-Dimensional) assignment problem, which is effectively solved by our proposed 2-D (2-Dimensional) iterative method. Simulation results show that our proposed iterative method can produce the close-to-optimal performance with low computational complexity. Moreover, comparing with existing schemes, our proposed scheme can not only enhance the system fairness but also improve the overall throughput.