Performance Analysis Of Satellite-UAV Network Based On NOMA

The stability and reliability of terrestrial communication systems are often affected by various factors such as man-made damage,natural disasters,and years of disrepair.In addition,the mobility and flexibility of terrestrial communication system are poor,and it is difficult to meet the requirements of emergency communication.With the development of the fifth-generation mobile communication technology,satellite communication and UAV communication have received extensive attention from domestic and foreign research scholars.Satellite communication has the characteristics of wide coverage,high mobility and flexibility,but during the communication process,there may be obstacles blocking,communication blind spots,long transmission delays,etc.,which cause the transmission quality of satellite communication to not be guaranteed.UAV relay auxiliary communication has unique advantages such as good maneuverability,low cost,easy deployment and control,flexible communication networking mode and convenient communication equipment update,which can achieve enhanced received signal power,increased system capacity and communication coverage.Therefore,hybrid satellite-UAV communication is of great significance for applications such as forest fire management,military reconnaissance,traffic monitoring,post-disaster reconstruction and rescue exploration and other applications.This paper mainly studies the system performance of satellite-UAV network based on NOMA,and the main works are as follows:Aiming at the problems of low stability and reliability,poor mobility and flexibility of terrestrial communication systems,a satellite-UAV communication system model based on NOMA was proposed.Then it is assumed that the system has p CSI,and the user is modeled by the channel gain sorting method,and the accurate expression of the system outage probability and the asymptotic expression of the system outage probability under high signal-to-noise ratio are derived.Finally,the system performance of the p CSI-based satellite-UAV NOMA network based on channel gain ordering is analyzed.Aiming at the problem that the channel gain sequencing modeling method used in the above system leads to poor system performance,and the assumption that p CSI leads to an infinitely small system outage probability,a new NOMA-based satellite-UAV communication system model is proposed.It is assumed that the system has imperfect channel state information,that is,there is Channel estimation error.And in order to obtain higher performance gains,we adopted the principle of random user pairing.Finally,the system performance of the ip CSI-based satellite-UAV NOMA network based on stochastic geometry theory is analyzed.For the two models proposed above,simulation experiments are used to verify the correctness of the theoretical derivation,and the traditional orthogonal multiple access system performance curve is compared as a comparison,which can intuitively see the superiority of the system performance using NOMA technology.Comparing the outage probability curves of the two models,it can be seen that the system performance modeled by random geometric theory is better than the system performance modeled by channel gain sequencing.This is due to the fact that random geometry theory is widely used to model the location of cellular mobile users.The advantage of using stochastic geometry modeling is that it can accurately describe the characteristics of random distribution of service users and facilitate the derivation of user performance expressions.Under the p CSI conditions,the system interruption probability can be reduced by continuously increasing the transmission signal-to-noise ratio of the system.However,under the ip CSI conditions,the system interruption probability has an error layer,that is,the system interruption probability cannot be reduced by infinitely increasing the transmission signal-to-noise ratio.