Performance Analysis Of UAV-based FSO/RF Cooperative NOMA Systems

With the continuous development of network communication technology,it has brought great influence to human life.It has changed people’s life style and improved people’s life quality,which also encourages people’s continuous exploration of communication network technology.In the process of the development of communication network technology,people found that limited spectrum resources could no longer meet the increasing development needs of human beings,the increasing number of communication terminals and the phenomenon of network congestion.The 4th Generation Wireless System technology could no longer meet the people’s demand for communication quality.It’s a hot research direction of communication network technology to improve the access of communication users and the quality of communication so as to improve the performance of the whole communication network.NOMA technology,as one of the key technologies of The 5th Generation Wireless System,can greatly alleviate the shortage of spectrum resources.FSO technology has the advantages of wide transmission band and large Communication capacity,also FSO can collaborate with UAV to provide Communication services for emergency locations effectively.Performance Analysis of UAV-Based FSO/RF Cooperative NOMA Systems,this paper combines UAV technology with FSO technology,use a UAV as air relay platform,and combines NOMA technology with it,focusing on the interrupt performance of the communication system and the influence of system parameters on the per formance of the communication system.At the beginning of the paper,the basic knowledge and key technologies related to the research are introduced.First of all from the first generation of mobile communications to the fifth generation of mobile communic ation in the application of Multiple Access technology is introduced,namely from the Frequency Division Multiple Access technology to the fifth generation mobile communication system popular non-orthogonal Multiple Access technology is presented,and the NOMA demodulation principle of the technology of the receiver and the physical security is presented.Secondly,relevant knowledge in FSO is introduced,including relay forwarding mechanism,including amplification forwarding and decoding forwarding protocol.In this paper,the UAV relay system model of FSO/RF is built,and NOMA technology is combined with the system to become a new communication system.More specifically,we assume that a UAV acts as a communication relay platform and use the DF protocol.The communication between source and relay is assumed to be FSO,and the signal path between UAV relay and two NOMA users is radio frequency communication mode.Based on the system model,the closed expression of interrupt probability is derived.In order to obtain diversity order information,we also carry out asymptotic analysis.The results show that the UAV flying altitude has significant influence on the system performance.In addition,indication errors and atmospheric turbulence also affect the performance of the system.Based on the previous system model,this paper simplifies the NOMA communication system.Considering the complexity of NOMA physical layer security research,the NOMA single-hop communication system is considered to analyze and study the NOMA system from the perspective of physical layer security.Specifically,the system assumes RF communication between the source and the two NOMA users,and that somewhere an eavesdropper attempts to eavesdrop on useful information sent from the source to the two legitimate users.On the basis of the system model,the closed expression of safety interrupt probability is deduced,and its correctness is verified by Monte Carlo simulation.