Research On Deployment Method And Handover Technology Of Airborne Base Station In Cellular Network

Under the conditions of continuous breakthroughs in key technologies such as the payload capacity and endurance of UAV.UAVs equipped with cellular base stations to provide communication services for ground users has become a research hotspot.With the spatial-temporal distribution of traffic changing dynamically,and the overlapping coverage of adjacent airborne base station,the UAV cellular network is difficult to respond and optimize in time.As an airborne base station,it has the characteristics of flexible deployment.It is of great significance to study the mobile control method which integrates intelligent technology to effectively improve the mobile handover capability and network performance.In this paper,we summarize the research status of UAV cellular communication network,and analyse the typical methods of UAV base station location deployment and mobile handover control.To meet the requirements of on-demand coverage and business continuity of UAV cellular base station,a mobile handover method for UAV cellular network is proposed.Firstly,the three-dimensional deployment optimization problem of UAV base station is decoupled into two dimensions:horizontal and vertical.In horizontal direction,the ground coverage center is determined by analyzing the spatial and temporal distribution of users based on data field theory.In vertical direction,the flight altitude is optimized according to the horizontal coverage radius center,and the three-dimensional deployment algorithm of UAV cellular base station is realized.Further,the intelligent handover decision method under UAV coverage is studied.According to the user's motion state and the potential influence of obstacle avoidance and bypass between adj acent users,a user's moving trajectory prediction model based on deep learning is established to predict user's trajectory,and an intelligent handover decision algorithm is designed and implemented.The test results show that the proposed method can realize the flexible deployment of UAV cellular base stations according to the space-time distribution characteristics of mobile users and traffic flow.It can deploy UAV cellular base stations according to the coverage radius on demand,and dynamically adjust the height to ensure the QoS requirements.The validation on Stanford pedestrian trajectory data sets shows that the handover success rate of the handover method based on trajectory prediction increases by about 8%.