Research On Performance Analysis And Optimization Of UAV Network

With the development of science and technology,unmanned aerial vehicles(UAVs)are widely used in the public and civil domains.On the one hand,UAVs can be used as auxiliary devices to assist traditional communication network to improve network performance.On the other hand,UAVs are convenient to deploy,flexible and low cost so that UAV network can be set up quickly to provide connectivity for devices without terrestrial communications infrastructure coverage.However,the high-mobility and energy constraint of UAVs also introduces many challenges to network performance.In order to improve the efficiency of UAV network,an UAV network is proposed and the network performance is analyzed.Besides,two novel optimization algorithms are proposed to improve the performance of the UAV network.The main contents and innovations are listed as below:A relay-assisted UAV network is proposed first.The factors affecting the network performance are studied with the consideration of channel states,flight altitude and flight trajectory.The expression of outage probability and throughput are derived under different relaying scheme.The impact of indicators on outage probability and throughput is summarized,which is the foundation for the optimization of UAV network performance.An UAV network that signal source is movable is proposed and the throughput maximization problem is analyzed first.Besides,a novel trajectory planning based on sequential convex programming algorithm(TP-SCPA)is proposed for fixed transmission power.Moreover,the effectiveness of the novel iterative algorithm is verified by simulation.The performance of the proposed algorithm is compared with the traditional successive convex optimization(SCO).Simulation results shows that the proposed algorithm is superior to SCO from the angles of iterations,convergence speed and simulation time.An energy harvesting driven multi-UAV network is established that aims to maximize the energy efficiency(EE).A novel algorithm called joint energy-harvest-time,resource allocation and trajectory optimization algorithm(JTRTA)is designed.The novel algorithm optimizes the above factors separately to maximize the EE of the proposed multi-UAV network,and the convergence of the iterative algorithm is proved.Simulation results show that JTRTA can effectively improve the EE of the network.This thesis discusses and designs a relay-assisted UAV network model,and the network performance is analyzed from different angles such as flight altitude and trajectory.The impact of different indicators on network performance are obtained.Two novel optimization algorithms are proposed to improve the throughput and EE of UAV network.