Research On Performance Analysis Of UAV-Aided Relaying Wireless Communication Systems

With the promotion of the global information technology revolution,wireless communication technology has been rapidly developed and widely applied,which greatly facilitates people's daily life and improves social productivity and production efficiency.However,the development of modern communication technologies is also facing higher requirements,especially in response to all kinds of emergencies,how to solve such emergencies more actively and effectively has become a major challenge for existing communication technologies.Unmanned aerial vehicles(UAV)are favored by the public due to their advantages of high maneuverability,low cost,reusability,zero casualties,rapid deployment and flexible configuration.UAV system can not only be used as a technical means of information transmission and acquisition,but also take advantage of its high autonomy and flexibility to carry out information collection and real-time monitoring of emergency sites.Therefore,the combination of UAV system and wireless communication technology has become a hotspot communication technology scheme.Physical layer security technology can effectively solve the problem of information security transmission brought by high-speed mobile and complex distributed environment to mobile users,and improve the security performance of wireless communication system.Free space optical(FSO)communication technology can effectively solve spectrum crisis,energy consumption and information security problems.In addition,combining the advantages of FSO technology with the high stability of radio-frequency(RF)wireless communication technology can effectively solve the problems of transmission link during communication deployment.From practical considerations,the endurance time of UAV may bring the risk of interruption to the aerial emergency supplement network,the adoption of energy harvesting technology can supplement the power consumption of UAV during flight and realize energy-saving communication.Therefore,from the perspective of UAV assisted collaboration,this paper mainly focuses on physical layer security,FSO/RF and energy harvestingtechnology,to conduct performance-related research on wireless communication network systems.The main research contents are as follows:This paper studies the physical layer security system based on UAV-aided aerial base stations(ABS).According to the situation of line-of-sight(Lo S)and non-line-of Sight(NLo S),the wireless channel is modeled by rician fading and rayleigh fading in systems,and amplify-and-forward(AF)protocol is adopted to comprehensively considers the distance between UAV and ground relay,path loss and other factors,three performance indexes of systems,namely,secrecy outage probability(SOP),strictly positive secrecy capacity(SPSC)and average secrecy capacity(ASC),are analyzed and simulated in detail.This thesis also investigates a energy harvesting for UAV-aided aerial relay(AR)two-hop FSO/RF communication system,and employs a scheme of decode-and-forward(DF)protocol at relay node to study the interrupt performance of whole system.Specifically,a new type of optical energy collection device based on FSO characteristic transmission is designed,and the DC components are recollected by the optical energy collection device to improve the energy utilization of UAV in heterogeneous network.In addition,the exact outage probability expression of the entire system is analyzed via the bivariate Fox-H function,and a series of simulations are implemented for different parameters in the expression.