Weak Signal Detection Method Based On Duffing Oscillator And Its Realization On DSP

The weak signal can be detected by chaotic oscillator owing to its propertyof sensitive dependence on initial conditions and immunity from noise. Based onthe study on method of weak signal detection by Duffing oscillator, this paperrealized Duffing oscillator detection system by using DSP (Digital SignalProcessor), which provides a way for weak sine signal detection by Duffingoscillator system to be utilized. By analyzing the spectrum of the output X ofDuffing system, the relations between the altitude and phase of driver powerinput and the altitude of fundamental wave component of output X is found, anda new method weak signal altitude detection is proposed, Called as Duffing_ML.Based on the analysis for characteristic of input-output of Duffing system, a newmethod to detect the phase of weak sine signal is proposed. Combining these twonew methods, the paper proposed double parameters(altitude and phase)weaksine detection method. For the length of detection only one cycle,the precision of new methods detectionare improved by a number lever,compared with Maximum Likelihood(ML)method. Newmethods have better detection precision and real time capability than traditionalDuffing detection methods.