Research On Interference Management Of Virtual Cells In Ultra Dense Networks

2019 is the first commercial year of 5G(The 5th Generation Mobile Communication Technology,5G).In the future,mobile communication traffic will show explosive growth.Under the impact of various new services,the communication capacity of 5G systems is facing great challenges.As a key technology to increase the capacity of communication systems,ultra-dense networks have become the research focus of scholars today.In order to improve the problems of frequent user handover and severe Inter-Cell interference in ultra-dense network systems,this paper adopts the user-centered virtual cell idea and introduces load balancing technology to reduce system interference and improve system resource utilization.The main research content is as follows:First,we establish an initial virtual cell for users in an ultra-dense network.As the network density increases,the virtual cell overlap area increases,the virtual inter-cell interference increases,and the system performance decreases.In view of this situation,we propose a virtual cell interference merging algorithm based on RSRP(Reference Signal Received Power,RSRP).By calculating the interference strength between virtual cells,the virtual cells with larger interference are merged to form a virtual cell cluster,and the original larger virtual inter-cell interference is converted into interference in the virtual cell cluster.We can use the collaborative transmission in MU-MIMO(Multi-User Multiple-Input Multiple-Output)to eliminate interference in the virtual cell on precoding technology.Then,due to the uncertainty of the number of users in the virtual cell cluster and the type of user services,there may be an imbalance in the load of some virtual cell clusters,resulting in low system resource utilization.To solve this problem,we introduce the load balancing technology of the virtual cell,select the optimal target virtual cell cluster for users in the overloaded virtual cell through the user's RSRP list,and sort the users to be transferred in the overloaded virtual cell.Transfer users to other light-load virtual cell clusters to improve user satisfaction and system resource utilization.Finally,we perform simulation verification on the proposed algorithm.The results show that the performance of our proposed RSRP-based interference merging algorithm is better than that of large-scale fading-based interference merging algorithms.After the introduction of load balancing,the number of unsatisfied users in the system decreases and the system resource utilization improves.