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ACTA AERONAUTICAET ASTRONAUTICA SINICA ›› 2015, Vol. 36 ›› Issue (10): 3418-3429.doi: 10.7527/S1000-6893.2015.0012

• Electronics and Control • Previous Articles     Next Articles

Weak signal detection with Duffing oscillator based on short time Fourier transform

NIU Dezhi1,2, CHEN Changxing1, CHEN Ting3, REN Xiaoyue1, WANG Zhuo1, CHENGMENG Jiangchuan1, JIANG Jin1   

  1. 1. Science College, Air Force Engineering University, Xi'an 710051, China;
    2. Xi'an Communications Institute, Xi'an 710106, China;
    3. School of Electronic Engineering, Xi'an University of Posts & Telecommunications, Xi'an 710061, China
  • Received:2014-10-17 Revised:2015-01-07 Online:2015-10-15 Published:2015-01-13
  • Supported by:

    Project supported by the Natural Science Foundation of Shaanxi Province (2014JM8344)

Abstract:

Time frequency characteristic of three statuses such as chaos, intermittent chaos and great period appearing in signal detection process with Duffing oscillator is studied and a frequency signal detection method based on new detection statistics is proposed. By analyzing on system output sequence in different statuses with short time Fourier transform (STFT), it is found that contour line of amplitude and three-dimensional time frequency distribution could represent differences of three statuses and recognize the three statuses utterly. Considering being easily operated on the detection statistics, amplitude-time characteristic in three-dimensional time frequency distribution is made as a foundation to weigh different statuses. Further, maximum of average value of number in amplitude-time characteristic corresponding to each frequency is set to final detection statistic, whose computation could be realized by fast Fourier transform (FFT) so that there will be high time effectiveness. On the basis of it, frequency control unit is brought in Duffing oscillator and scheme of any frequency signal detection is given. The key point of the scheme is to find the maximum among all detection statistics and makes its matching frequency as one port of unknown signal frequency range. Then the other port is the matching frequency of secondary maximum among other two detection statistics adjacent to the maximum. After experiment, the range of detection statistics of each status is given. Thus, according to the range, any frequency signal detection by Duffing oscillator is realized, which shows feasibility of the method and provides one new thought for studying signal detection problem with Duffing oscillator.

Key words: Duffing oscillator, intermittent chaos, short time Fourier transform, three dimensional time frequency distribution, detection statistic, signal detection

CLC Number: