Design And Research Of A Spectrum Monitoring Wireless Sensor Network

Because frequency modulation(FM)broadcast information processing technology is mature,equipment installation costs are low,and system maintenance is simple,it is widely used in audio information broadcasting in the civilian field.Illegal installation of transmitters,the broadcast of vulgar content,illegal advertising,spreading rumors and other situations often occur.The monitoring equipment used by the radio monitoring management center is expensive and difficult to maintain,and network communication between the equipment cannot be performed.And mainly relies on man-made operations or the masses to report complaints to find illegal broadcasts.Therefore,it is of great practical significance and application value to study a spectrum monitoring system which can realize network communication and automatically determine the legitimacy of signals.This article proposes a spectrum monitoring wireless sensor network system.The system can realize the acquisition,transmission,processing,analysis and result display of FM broadcast signals in the monitoring area.The main research work is as follows:1.Design of monitoring node.Aiming at the shortcomings of the existing spectrum monitoring methods,a systematic monitoring node is designed.This node uses the CC2530 chip as the control module and the TEA5767 chip plus peripheral devices as the FM signal receiving module.Through experiments,it is verified that the spectrum monitoring node designed by the system can realize the acquisition of FM broadcasting signal with frequency band range of 87-108 MHz,and network communication and wireless data transmission can be realized among the nodes.2.Application of data fusion technology.In order to solve the problems of data redundancy when the monitor terminal receives data,a data fusion algorithm is embedded in the monitoring system.An adaptive weighted fusion algorithm based on fuzzy logic is used to fuse the data transmitted by each monitoring node,which effectively solves the problems of data redundancy and low transmission rate.It is proved that the algorithm can effectively solve the problems of data redundancy.3.Signal extraction algorithm.Because the data collected by the monitoring node has many peak signals and is greatly affected by environmental noise,the fusion algorithm adopted by the monitor terminal side retains as much original data as possible.Therefore,the system uses a signal extraction algorithm based on the Fibonacci multi-mode optimization algorithm,namely the FDIK(Fibonacci DBSCAN and Improved K-means)algorithm,to effectively and accurately extract the peak signal.Through simulation and testing in practical applications,it is found that the error rate of the peak signal extracted by the FDIK algorithm is low,which can effectively and accurately extract the peak signal.4.Signal decision algorithm.In view of the shortcomings of the existing methods of identifying illegal signals,this paper adopts a simple threshold algorithm to realize the decision on illegal signals by combining the data features collected by monitoring nodes and all legal FM broadcasting signals in the monitoring area.The effective judgment of FM broadcasting signals in different regions is realized.5.Design of upper computer software.The human-computer interaction interface for monitoring FM broadcast signals is constructed,and a data display interface is developed and designed on the PyCharm platform,including frequency,level value,error rate,legal rate,and whether it is legal.The test results show that the designed upper computer software can meet the requirements of system design.