Research On Key Technologies Of Multi-user Communication For Unmanned Aerial Vehicle Network

In recent years,UAV has been widely used in the field of wireless communication by virtue of its advantages such as simple operation,flexible application,strong adaptability and wide coverage.Therefore,UAV communication network has become a research hotspot of scholars at home and abroad.However,due to the broadcast nature of wireless media and the feature that UAV communication can provide line-of-sight transmission,information is easy to be intercepted by illegal users,which affects the security performance of UAV communication network to a certain extent.Based on the above background,this paper mainly studies the key technologies of multi-user communication for UAV network.The main contents and innovations of this paper are as follows:Firstly,the UAV communication network with eavesdropping nodes is considered,in which the leakage of confidential information transmission caused by eavesdropping nodes deteriorates the physical layer security performance of the UAV communication network.In this scenario,this paper adopts the security capacity based on the difference between transmission channel capacity and eavesdropping channel capacity as the criterion of multi-user selection,proposes a multi-user scheduling scheme with maximum security capacity,and analyzes the security interrupt performance of the proposed scheme.The simulation results show that,compared with the polling scheduling scheme,the proposed multi-user scheduling scheme significantly improves the security capacity of the UAV communication network and reduces the security interruption probability of the UAV communication network.Secondly,a UAV communication network with eavesdropping nodes and friendly jamming nodes is considered.One user sends signals,and the friendly jamming node sends jamming signals to counter the eavesdropping nodes.In this scenario,two schemes of optimal user random jamming and optimal user random jamming are proposed,and the expressions of secure interrupt probability of UAV physical layer secure communication under mixed channel environment of Rice and Rayleigh are derived,and the performance of the two schemes is compared.The simulation results show that compared with the optimal random user jamming scheme,the optimal user random jamming scheme can significantly improve the system performance.In addition,by increasing the number of users on the ground,the safety outage probability can be significantly improved under both scenarios.Finally,considering the resource allocation fairness problems of UAV communication network,including UAV by means of orthogonal frequency division multiple access at the same time provide the ground more than one user communication coverage,with the aim to optimize the system capacity,the percentage rate for fairness constraint,to resource allocation model of UAV communication network to an optimization problem.In this scenario,a proportional fair multi-user scheduling scheme is proposed,and the system performance of the proposed scheme is analyzed.The simulation results show that compared with the round-robin scheduling scheme and the optimal user scheduling scheme,the proportional fair multi-user scheduling scheme can effectively achieve the balance between the system throughput and the fairness among users.In addition,by adjusting the deployment position of the UAV,the system capacity can be further increased.