Research On Communication Performance Optimization Based On UAV-Assisted Wireless Communication

UAVs can not only be used as auxiliary equipment to assist traditional networks to communicate and improve network performance;they can also quickly build UAV networks to provide connections for ground communication facilities.However,UAVs have the characteristics of high mobility and limited energy,which bring many performance challenges to UAV-assisted wireless communication.According to the communication requirements of specific emergency scenarios,the thesis studies the throughput maximization of UAV-assisted wireless communication systems in natural disaster scenarios.As an aerial base station and mobile relay assisted to destroy the ground base station to communicate,the drone assisted wireless communication model was established,and the air-to-ground channel characteristics of the aerial base station model and mobile relay model and the drone flight height analyze and study the factors affecting network throughput such as flight trajectory and interruption rate.The trajectory planning and system throughput maximization scheme of UAV as an aerial base station and mobile relay is proposed,and the optimized part of this paper is mathematically modeled,and the sine cosine optimization algorithm is used to iteratively solve the throughput optimization problem.Finally,a simulation experiment is carried out.The experimental results show that the established UAV aerial base station and mobile relay-assisted communication model can effectively improve the throughput of the network system.(1)The performance of the UAV network is analyzed,and the factors affecting the UAV network throughput and other performance indicators are discussed.Including UAV flight altitude,flight trajectory,power control and other factors on the network throughput,interrupt probability and other indicators.(2)Improve the existing master-slave UAV aerial base station model,and propose an optimization problem with the goal of improving the throughput of the aerial base station system.The channel model of the improved master-slave UAV base station,the optimal flight height of the master UAV and the flight trajectory of the slave UAV are analyzed.Optimize the coverage radius and flight trajectory of the master UAV,and the bandwidth allocation between the master UAV and the slave UAV,establish a corresponding optimization model,and finally solve the problem of maximizing the minimum throughput of all users.(3)The thesis designs a full-duplex UAV mobile relay wireless communication system,with the optimization goal of maximizing network throughput.The system dispatches UAVs to a group of energy-constrained ground terminals for information collection,maximizes the throughput of the system by optimizing the flight trajectory of the relay UAV,and mathematically models the optimization part.The optimization problem is divided into two sub-problems to be solved step by step: communication scheduling and power allocation optimization under a given fixed trajectory,and trajectory optimization under a given fixed communication scheduling and power allocation.Using the existing sine and cosine optimization algorithm,iteratively solve the problem of relay UAV flight trajectory and system throughput optimization.The thesis studies the aerial base station and mobile relay model of UAV,and models the corresponding auxiliary network model.The air-to-ground channel state of UAVs based on lineof-sight and non-line-of-sight communication links is discussed.By optimizing the UAV’s flight trajectory,coverage radius and bandwidth allocation,an optimization model for maximizing the throughput of the UAV-assisted communication system is established.Since the optimization problem is a mixed integer nonlinear programming problem with non-convex characteristics and cannot be solved directly,the thesis divides the optimization problem into two sub-problems,which are solved iteratively through an improved sine-cosine optimization algorithm and simulated by experiments.The simulation results verify the superiority of the established UAV-assisted wireless communication model in maximizing the throughput of the air-to-ground communication system.