Design And Application Of Automatic Monitoring System For FM Broadcasting

With the rapid development of the national economy and national defense construction,radio spectrum resource has become the scarce strategic resources.In the information technology,automation,intelligent building and development process,to promote their business,civil aviation,rail,marine development,meteorology and other industries dependent on wireless technology more and more.Recently,wireless technology has been the important mean to improve production efficiency and ensure safety in production.FM broadcasts is an import application for radio technology.FM broadcasts play an important role in enriching people's lives and ensure traffic safety,disaster search and rescue and so on.However,some illegal FM broadcasts have been found in recent years,such as radio broadcasting of counterfeit drugs,propaganda discordant information.These broadcasts have seriously affected people's lives and safety.Therefore,in order to safeguard the people's normal life,FM radio monitoring is necessary.But the monitoring of FM broadcasting have some problem: the degree of automation is not high,the monitoring cost is high and the monitoring efficiency is not satisfactory.In order to reduce the workload of monitoring personnel and improve the monitoring efficiency,automatic monitoring system for FM broadcast is achieved based on the study of the FM broadcast monitoring.The main contents are as follows:1.Research on the algorithm of the system:For the radio signal search,a fast algorithm for signal search is proposed after studying the previous signal search algorithm.This algorithm firstly preprocess the frequency band scanning data,the frequency band is segmented by the preprocessed data,then the adaptive threshold line is made on each segment to determine and identify the signal center frequency,finally,the signal is determined through the statistics;Occupancy rate calculation and storage.Frequency band occupancy and channel occupancy rate is calculated by the adaptive threshold line in this paper,then a save storage space occupancy rate way is proposed.The occupancy rate of any period of time is calculated by this storage way;Measured bandwidth calculation.The theoretical bandwidth calculation method is provided by ITU requires a high data requirement,however,the data in actual monitoring is often unable to meet the theoretical requirements,so it is necessary to process the original data before calculating the impact on calculation of bandwidth from poor quality data and quiet period of the data.2.Design and implementation of the core module of the system:System boot module is mainly used to initialize each plug-in of the system.Basic parameters are selected by monitoring personnel,such as,radio transmission protocol selection,monitoring mode selection,monitoring device parameter setting and user authentication.Firstly,frequency band scan task is release by automation module;Secondly,signal is calculated by signal search algorithm.Middle-frequency parameters are obtained by IF measurement and medium frequency direction finding(MFDF),such as,signal strength,direction and so on;finally,in order to monitoring personnel release monitoring task,nature of the signal is determined by the method of determining the nature of the signal and the determined signal is stored in the database manual monitoring module.These frequency monitoring tasks include scanning tasks,IF measurement tasks and MFDF tasks.The paper implements the automatic monitoring software of FM broadcasting base on the above algorithm,this software implements the following main functions: first,Software can be used for automatic monitoring;Second,the software have manual monitoring mode and automatic monitoring mode,monitoring personnel can choose according to the actual situation,to achieve complementary two monitoring mode;Third,system package has a variety of radio transmission protocol,to achieve the compatibility of different protocols.Each task is independent and the monitoring data is returned;the encapsulation of the radio transmission protocol based on SCPI is completed by protocol encapsulation module.In the system,the protocol class is called to realize the compatibility between different systems;the operation of the database is related by data storage module and data playback module.The data is stored in different data tables according to different monitoring data.The data is read and displayed on the user interface through the query condition during playback.Finally,the system is tested.After testing,the system can realize automatic monitor task for FM broadcasting and achieve the desired monitoring results.