Research On Radio Monitoring Network And TDOA Localization Technology In Urban Environment

With the rapid development of modern communication technologies,various types of radio equipment are constantly emerging.How to manage radio stations scientifically and efficiently becomes more and more important,and the demand for building high-level radio monitoring networks is becoming stronger.A perfect radio monitoring network can not only ensure the normal and stable operation of legal radio stations,but also investigate and deal with violations of black stations,which has a strong practical significance for the healthy development of communication technology.The main purpose of this thesis is to analyze the radio monitoring network coverage and TDOA network positioning technology based in urban environment,provide a theoretical basis for the scientific deployment of radio monitoring stations in Nanjing,increase the coverage of monitoring networks,and analyze the large-distance TDOA network feasibility.The author investigates the research status of radio monitoring systems at home and abroad,summarizes the characteristics of gridded radio monitoring networks in other cities,and analyzes the network architecture of radio monitoring networks in Nanjing based on the radiolocation scenarios of urban environments,and the sensitivity of each monitoring station.The electromagnetic background level was calculated,and the common electromagnetic propagation model was compared and analyzed.The ITU ground semi-empirical propagation model(ITU-R P.1546-5)suitable for simulation is selected.Next,The author discusses the coverage of radio monitoring networks in urban environments.According to the requirements of the National Radio Administration for radio monitoring network functions and capabilities assessment requirements,the use of Python-based radio monitoring network coverage visualization analysis software is based on the model(ITU-R P.1546-5).The empirical propagation model(ITU-R P.1546-5)and the performance parameters and target parameters of each monitoring station simulate the coverage of the radio monitoring network in Nanjing,and find the coverage blind area of the existing monitoring network,and according to the electromagnetic environment in the area where the blind area is located by the road testing data and terrain,peripheral radiation sources,proposed a new site deployment plan to increase the coverage by 10%.Then,working principle and network coverage are compared and analyzed between TDOA and AOA,and analysis result demonstrates the advantages of TDOA networking technology in coverage.At the same time,the TDOA networking positioning experiment in real urban environment is finished by transforming the existing radio monitoring station.Through the different networking mode positioning error simulation and TDOA experiments,the author analyzes the relationship between the number of radio monitoring stations,the nature of the target,and the positioning error,and demonstrates the feasibility of implementing TDOA networking in Nanjing's existing large-distance radio monitoring network.