Performance Analysis For UAV-assisted Cellular System

In the future,with the popularity of Internet of Things applications,wireless networks will support 100 billion connected wireless devices,and the current cellular infrastructure will meet huge challenges.In addition,in temporary and emergency scenarios such as sports events,outdoor concerts,natural disasters,etc.,ground base stations often overload or fail,but deploying ground communication facilities temporarily is time-consuming and costly.This paper considered Unmanned Aerial Vehicle(UAV)as aerial base station to solve the communication problem of temporary and emergency area.The work has expanded the network coverage and improved the service performance by establishing a joint air-ground communication system.The main work of the research is summarized as follows:Aiming at the dense information receiving area,research was conducted on the use of UAV and ground base stations to provide services jointly.According to the characteristics of the base station distribution,the user was assumed to connect to the nearest base station.This paper has derived the association probability and the coverage of the overall communication system.Simulation results verify the correctness of the theoretical derivation.In addition,this paper further investigated the impact of UAV altitude on the correlation probability and coverage.Combined with the density deployment of base stations,the best flight altitude to maximize system coverage have been found.Aiming at the temporary blind spots,research was conducted on the use of UAV to replace the failed base station.According to the characteristics of ground base station and user distribution,this paper has derived the Laplacian expression and system coverage probability,and verified it by simulation.In addition,this paper focused on the fading parameters of the Nakagami-m channel and the path loss factor,and analyzed the impact of obstacles on the received signal quality.Based on this,the best coverage performance for different sizes of areas has been achieved through control of the UAV altitude and the beam width of the transmitting antenna.