Study On Weak Signal Detection Based On Chaos And Stochastic Resonance

Traditional signal detection methods cannot detect weak signals with low signal to noise ratio(SNR)and signals with unknown noise distributions as well.In order to solve these problems,this paper presents a method based on typical chaotic systems and stochastic resonance system in nonlinear system to detect characteristics of weak signals.Besides,Simulation and application research are realized.The phenomenon of chaos,chaotic characteristics and a quantitative description of the chaotic state are introduced in the paper.And motion state of Duffing system is studied and simulated with Simulink software package,and it is verified that the amplitude of the signal can be detected in the system with periodic signals input.,At the same time,the stochastic resonance phenomenon,bistable system,stochastic resonance measure index and stochastic resonance of the classification are introduced.Meanwhile,Stochastic resonance effect under periodic input signal is researched.The signal frequency which could be detected is testified under MATLAB/Simulink environment.And the general waveform of detected signals with non-periodic signals input is also studied,with a method of utilizing stochastic resonance effect.The theory of stochastic resonance is combined with Duffing system in this paper,and stochastic resonance effect can be used to detect the frequency of periodic signal.Furthermore,the periodic driving force frequency of the Duffing system is set to the detected frequency,and then the amplitude of the periodic signal could be detected.In a word,detection of amplitude and frequency of the periodic signal is realized,and a new way to detect the weak signal is established.