Research And Application Of Variable Frequency Hopping Communication Technology

With the rapid development of communication technology,the wireless communication has gradually become the mainstream of modern communication way.Due to the establishment of many communication networks,exemption application of ISM band is more crowded,all kinds of electromagnetic interference is more and more serious.In the industry control system,because of the complex environment and the existence of man-made or natural disturbance,the quality of the traditional fixed frequency wireless communication will decrease and even interrupt.Especially in some important security control systems,communication system with malicious attacks,will cause a huge loss.Correspondingly,the variable frequency hopping(FH)communication technology has advantages of anti-jamming,anti-reconnaissance and the resistance to intercept.So it has great research value in industrial control field.This paper studies the component and basic principle of the FH communication system,which introduces the key technologies of FH communication,including pseudo random sequence,variable FH frequency synthesizer and synchronization technology.Depending on the basis,the paper gives the overall design scheme of variable FH communication systems,and models and simulates on each module to verify the feasibility of the program by Matlab/Simulink simulation platform.For the anti-jamming performance of variable FH communication systems,this article analyzes the broadband noise,partial band noise,multiple frequency and track interference.This article studies theoretically the performance of the variable FH communication under various interference,and builds the simulation model combined with the theory analysis and characteristics,which gets bit error rate curve.The result shows the performance of variable FH against all kinds of interference.At last,the paper presents an overall structure of variable FH system based on real-time link quality analysis,and an adaptive control method,which focus on the variable FH source hardware circuit design based on the established system simulation model.Combined with the advantages of PLL and DDS,the paper designs a high precision,stable performance of variable FH source,which has made an important step in variable FH communication system of practical application.