Research on Joint Mode Selection and Resource Allocation Scheme in D2D Networks

In this paper, we consider a single-cell spectrum sharing system, in which there exist multiple cognitive device-to-device (D2D) pairs and cellular users (CUs). For such a system, in order to improve the overall spectral efficiency, we propose a joint mode selection and resource allocation scheme. In detail, a mode selection criterion is firstly built by utilizing the knowledge of channel gain ratio; then, for different modes of D2D users, a resource allocation strategy based on greedy algorithm is derived. Finally, by exploiting the genetic algorithm, dichotomy and Lagrange multiplier method jointly, we further optimize the power allocation scheme. Simulation results demonstrate that the proposed scheme is able to enhance the spectral efficiency of the considered system.