| With the rapid development of communication technology,various radio devices have been proposed and the problem of how to manage these devices scientifically and efficiently has become more and more important.At the same time,the demand for establishing monitoring systems is becoming more and more urgent.A perfect monitoring system can not only guarantee normal operation of radio equipment,but also crack down on illegal devices.It has vital practical significance for the healthy development of communication technology.This project mainly studies the full-band real-time monitoring and high-precision localization of radio stations.It aims to design a system consists of hardware and software which could accurately locate the radio devices.This paper introduced the common methods of localization technologies and the working principle of them according to current researches on radio monitoring systems both at home and abroad.In consideration of the scene of radio localization,TDOA was selected owing to its high precision and Chan algorithm was used for calculating the positing model of TDOA.Furthermore,a numerical simulation was conducted in order to examine the performance of localization algorithm.After that,this paper discussed the evaluation standard of the construction of a full-band radio monitoring system.Then it studied the implementation of hardware and software architecture.This paper also took Nanjing as an example in order to determine the influence of placement of base stations.And the result indicated that performance of localization could be improved by using a non-collinear placement and increasing the number of base stations.The distance error of localization in most areas in Nanjing was less than 10 meters when the standard deviation of TDOA measurement was set 1ns.Subsequently,white noises and FM radio signals were chosen as the representatives of wide-band and narrow-band signals.Then these two kinds of signals were tested by group-delay algorithm and phase-delay algorithm.By combining those methods,a new algorithm called “joint algorithm of time-domain correlation,group delay and phase delay” was proposed.The result of experiment demonstrated that the standard deviation of TDOA estimation was less than 0.7ps when processing FM radio signals by this algorithm.Finally,this paper introduced how to design the software of radio localization system with Python and PyQt.It also demonstrated the process of time-delay estimation and radio localization.By using API provided by Baidu Map,the GIS module was embedded in the software interface,and the json file was used for data transmission.The target could be displayed in the map and this project could meet the requirements of full-band real-time monitoring system. |
