The invention discloses a
weak signal detection method based on joint denoising and
frequency modulation, and belongs to the technical field of
signal processing. The method comprises the steps that 1) partial
noise suppressing is carried out on low
signal to
noise ratio signals which are to be detected and are mixed with
noise through an
autocorrelator; 2)
wavelet threshold transforming is carried out on the signals which are processed in the step of 1) and are to be detected, so as to remove
residual noise after
signal autocorrelation; 3) a modulatable standard signal is used to modulate the frequency of the signals output in the step of 2), so that the modulated
signal frequency can meet the detection condition of a dual Duffing oscillator difference
system, and
high frequency signals in the modulated signals are filtered out through a
low pass filter; 4) the signals output by the
low pass filter in step of 3) are input into the dual Duffing oscillator difference detection
system, and initial state parameters of the
system are set; and 5) whether the dual Duffing oscillator difference detection system has the phenomenon of regular intermittence chaos is judged, and if the phenomenon of regular intermittence chaos occurs, a continuous zero method is used to acquire an intermittence chaos period and the frequency of the signals to be detected. Compared with a traditional detection method, the method can be used to detect the weak signals of any frequency in a background with strong noise, and is of great significance in practical application.