Test And Uncertainty Evaluation Of 800MHz TETRA Digital Trunked Base Station

Wireless communication has become the mainstream communication mode because of its convenience and efficiency.With the development and progress of technology,there are more and more types of wireless communication,which occupy more spectrum resources.This leads to increased interference between different devices in the adjacent frequency range.Therefore,as a radio management unit,its workload is increasing.In order to reduce workload and improve work efficiency of field test,an automatic test system is designed in this paper.The automatic test system can automatically test the radio frequency index of TETRA digital cluster base station by controlling spectrum analyzer,signal generator and other equipment.Firstly,the paper introduces the background of topic selection and the practical significance of research,based on this analysis of the current digital cluster base station test problems,and put forward the development of automatic test system to solve the problem.Secondly,the technology and theory of automatic test in communication field are discussed.On the basis of introducing the basic content of communication automatic test system,this paper analyzes the instrument control bus(GPIB),studies the SCPI standard instruction set of control instrument,discusses the related content of VISA function library,and discusses with the example of program development.The overall structure of automatic test system is analyzed emphatically.The overall structure of the hardware part of the automatic test system,the hardware units involved in the automatic test and the connection mode are analyzed.This paper discusses the general structure of automatic test software,which is divided into three parts: control interface,automatic test program and test data writing and reading.Design the functions and interfaces of each unit.The software composition and running flow of automatic test system are analyzed.On the basis of the overall structure design,the program design of 800 MHz TETRA base station automatic test system is completed.The TETRA base station automatic test project,using equipment and system connection are analyzed.According to the standard instruction set of SCPI and the basic content of VISA function library,the automatic test program of each test item is written,and the automatic test result is given.Finally,according to the practical work summary,the difficulties in testing wideband noise and stray emission of TETRA base station are analyzed,and the solutions are given.The uncertainty analysis of the automatic test system is completed.On the basis of analyzing the related contents of rf test uncertainty,the analysis and calculation methods of class A uncertainty,class B uncertainty and composite uncertainty are discussed,and the mathematical model of uncertainty is constructed.According to the specific situation of this automatic test system,the calculation of uncertainty is discussed,and the uncertainty rule table of this automatic test system is given.