UE grouping and mode selection for D2D communications underlaying a multicellular wireless system

Network-assisted Device-to-Device (D2D) communication is a promising technology for next generation wireless systems being seen as a means to improve spectrum utilization and reduce energy consumption. However, D2D communications can generate significant interference to cellular communications when resources are shared by both types of communication. Aiming at the reduction of the intracell interference and spectral efficiency improvement, we formulate and analyze methods to group conventional and D2D-capable User Equipments (UEs) for shared resource usage and to decide if D2D-capable UEs should communicate directly or via the Evolved Node B (eNB). The results show that D2D communications can improve the spectral efficiency of the system and that most of this improvement can be achieved by suitably grouping the UEs for sharing resources.