Joint Uplink and Downlink Resource Allocation for D2D Communication Underlying Cellular Networks

Device-to-device (D2D) communication is a promising technique to improve the spectral efficiency of cellular networks. In this paper, we investigate the joint uplink and downlink resource allocation problem to maximize the sum data rate of the system while guaranting the quality of service (QoS) for both cellular user equipments (CUEs) and D2D user equipments (DUEs). In particular, we jointly consider both the uplink and downlink subcarrier resources for DUEs to reuse and formulate the optimization problem as a mixed integer nonlinear programming problem (MINLP) which is generally NP-hard. To make the problem tractable, a two-step scheme is proposed. First, the optimal power allocation is formulated as a non-linear programming problem and the optimal solution is achieved by searching among a finite set. Then, a maximum weight bipartite matching scheme is developed to select the best subcarrier for each DUE. Simulation results show that our proposed algorithm can significantly improve the system performance.