Research And Design On Wireless Signal Multipoint Positioning System Based On UAV

With the rapid development of radio technology,the application of wireless communication is more extensive.But the increasing serious radio interference is not only manifested in disrupting the normal order of broadcasting,it also interferes with the normal civil aviation wireless communication,endangering people's lives and health as well as national security and stability.Therefore radio monitoring is particularly important.Radio location algorithm is used to locate the source of radio signals to ensure the safety of people's lives and property.So far,the lack of radio spectrum in the world makes it be necessary to understand the distribution of electromagnetic environment in a region's three-dimension space.However,the current use of ground monitoring is not enough,the cooperation of airborne radio monitoring will become more important.This thesis focuses on radio positioning technology.It focuses on the hardware design of the radio receiving platform and the algorithm technology of multi-machine cooperative joint positioning under the condition of multi-monitoring targets.On the basis of theoretical research,the system software is designed and finally test case verification experiment is completed.The main research content of this thesis includes the following parts.First,The principle of software radio and passive location technology are introduced.The basic theory and key method of software radio technology are analyzed.The software radio communication architecture is summarized.Besides,based on the basic principle of passive location,the advantages and problems of traditional location algorithms are analyzed and compared.AOA-TDOA joint positioning scheme based on UAV multi-aircraft cooperation airborne is selected as the next major algorithm research direction.Second,the hardware of the radio receiver in the airborne platform is designed.After theoretical analysis of radio signal processing,the signal receiver platform takes LMS7002 M module as the rf core part of the design,and the front-end rf part and the digital signal processing module FPGA communicate with each other to constitute the overall hardware core framework structure.It adopts the latest technology and chip module to make the hardware circuit designing of rf front-end and baseband processing,and PCB version rendering to make the hardware receiver platform.Then,the joint localization algorithm based on passive localization is optimized.The traditional localization algorithm and its practical application are studied.In order to improve the accuracy of false point culling,the traditional algorithm was abandoned and a new algorithm was proposed to solve the false point problem.Multiple receivers in the air are used as the monitoring platform,and centralized sequential fusion method is adopted to track and locate the monitoring source in the arbitrary motion state in the three-dimensional space.Thesignal acquisition and positioning simulation is realized,and the data is analyzed to further improve the algorithm and the positioning accuracy of the system.Finally,the system software is designed and system is tested.On the basis of hardware design and algorithm research,the system software architecture and related monitoring and positioning functions are designed.The positioning algorithm and practical application requirements are studied,and the joint positioning algorithm suitable for the existing hardware environment is designed to coordinate the performance of software and hardware.The software design of this paper is based on CS architecture.The design of the software system to make a system test case,and finally according to the actual needs of the site to complete the field test,draw a conclusion.