Chaos Characteristics Analysis And Interference Research Of Frequency Hopping Sequences

The FH communication is widely applied in modern military and civil communiti-on because of its advantages such as anti-jamming, anti-fade, anti-capturing, channelsharing properties and multi-access networking etc.Currently, the study of modeling andforecasting for frequency hopping code that is using chaotic analysis and neuralnetwork is carrying out closely, and have achieved some results.This paper mainlyanalyses frequency hopping yards by characteristics of chaotic dynamic and researcheschaos characteristics of frequency hopping sequence, and forecast the laws for jump tochange of fh sequence through the method of neural network, at last, the paper analysesthe interference of chaotic noise.At first in the paper, the general situation of spread spectrum communication andfrequency hopping communication is expounded and the working principle andcharacteristics are analysed. Briefly introduced the chaotic systems and the properties ofchaotic dynamics.The paper calculate the correlation dimension by G-P algorithm andcalculate the biggest index of Lyapunov by Rosenstein algorithm. They all have thecharacteristics of chaos and predictable through the analysis of frequency hopping yards(m sequences, RS sequences and nonlinear sequences). We have the followingconclusion:(1) They have a very clear strange attractor and the correlation dimension isnot an integer that has the fractal characteristic.(2) They extremely sensitive to theinitial value condition and the biggest Lyapunov index is a limited value, is not infinite.so the research shows the frequency hopping code is not random, but can be predicted,so they all have the characteristics of chaos.Secondly, using BP neural network and RBFneural network to forecast the frequency hopping yards and comparing the performanceof the predict model through theoretical analysis and simulation experiments. Finallythe article analyzed the interference of chaotic white noise, and proved white noise canbe used as an interferential signal through the simulation.The simulation experiment results show use this method not only predict but alsointerference the frequency hopping and has practical value.