Dynamic Virtual UE in Ultra Dense Networks: Forming Procedure and Design Insight

Recently, significant researches have been devoted to develop some remedial solutions to cell-edge effect issues such as inter-cell interference coordination and coordinated multipoint transmission. However, they were unable to completely remove the cell-boundary effect and led to increased complexity and overhead. In order to realize the gain of user virtualization, this paper proposes a tractable virtual user equipment (UE) forming procedure in which a set of qualified UEs is selected to serve as small cells. Specifically, the UE group completes discovery and connection among each other in a self-organized manner, and the donor femto transmission point (FTP) manages the data transmission and handover of the virtual UE group cooperatively. Meanwhile, the context information from both users and networks is utilized to locally optimize the composition of the virtual UE group, which adapts to each user's environment and quality of service (QoS) requirements. Simulation results illustrate that the virtual UE design achieves an increase of maximum 65% for success probability under high spectral efficiency request compared to the LTE system and efficiently improves average user throughput.