基于小波變換與混沌系統(tǒng)的微弱周期信號(hào)檢測(cè)方法

基于小波變換與混沌系統(tǒng)的微弱周期信號(hào)檢測(cè)方法

提出了基于小波變換與混沌系統(tǒng)的微弱信號(hào)檢測(cè)方法。根據(jù)小波變換具有的多分辯能力與混沌系統(tǒng)對(duì)微弱周期信號(hào)的敏感性和對(duì)噪聲的免疫力，將混有強(qiáng)噪聲的周期信號(hào)經(jīng)小波變換處理后作為處于混沌臨界狀態(tài)的Duffing系統(tǒng)的輸入，根椐系統(tǒng)狀態(tài)從混沌到周期的相軌跡的變化來(lái)檢測(cè)微弱周期信號(hào)。仿真結(jié)果表明，最低檢測(cè)下限可達(dá)-166dB，檢測(cè)信噪比可達(dá)-116db。
Based on wavelet transform and chaotic system, this paper puts forward a method for weak signal detection. According to the multi- resolution of the wavelet and the sensitivity of weak periodical signal and the immunity to noise of the chaotic system, we made the periodical signal with strong noise processed by wavelet as the input of the critical Duffing system, detecting the weak periodical signal by the transformation of the phase trajectory. It shown from the simulation that the detection lower limit is –166dB and the SNR (Signal Noise Ratio) is approximate to –116dB.