QoE-Aware Resource Allocation for D2D Communications in Unlicensed Spectrum

This paper studies the QoE-aware resource allocation for device-to-device communications in unlicensed spectrum (D2D-U), which can meet the explosively growing data traffic and provide higher user's satisfaction in 5G networks. Specifically, channel access and power allocation are jointly considered for the D2D-U system and an optimization problem is formulated with the objective of balancing the overall system throughput and fairness of D2D-U and WiFi for coexistence. In order to reduce the complexity, this problem is decomposed into two subproblems, accordingly, two algorithms are proposed which are QoE-aware power allocation algorithm and rate-based fair duty cycle algorithm (F-DCA). In the QoE-aware power allocation algorithm, we employ the difference convex (D.C.) method to transfer the non-convex problem into convex optimization, which can greatly reduce the complexity. In the F-DCA, we adopt an iteration method to allocate the appropriate time proportion for the D2D-U system adaptively according to the load of the WiFi network. Simulation results show that our proposed algorithms achieve better performance compared with the traditional methods.