Tri-stable stochastic resonance based research on ZPW-2000 frequency shift signal detection methods
In response to the inevitable damage to useful signals caused by the harmonic interference detection technology of ZPW-2000 frequency shift signals in suppressing noise,a tri-stable stochastic resonance system was proposed to convert some noise energy into frequency shift signal energy so as to reduce the energy loss of frequency shift signals. First,the center frequency of the frequency shift signal was shifted from the higher frequency band to the lower frequency band,with an emphasis on studying the useful frequency bands of the frequency shift signal. The scale variation coefficient of 1000 was selected to ensure that the input signal could satisfy the stability of numerical calculation in the process of scale change,and the small parameter signal after scale transformation could satisfy the adiabatic approximation theory. Second,the tri-stable stochastic resonance system was optimized using the Chaos Sparrow Search Optimization Algorithm (CSSOA),and system parameters a,b,c,and γ were obtained with the maximum output signal-to-noise ratio (SNR). Subsequently,the frequency shift signal shifted to the low frequency range was input to the optimized tri-stable stochastic resonance system to achieve signal noise reduction. Finally,the low frequency signal was detected with Zoom Fast Fourier Transformation (ZFFT). Simulation results reveal that from comparing the spectrograms of the shifted signal before and after processing by the tri-stable stochastic resonance system,it is evident that the frequency domain features are enhanced,and the energy of the shifted signal remains unharmed concurrently with the noise reduction. The output signal-to-noise ratio can be enhanced by at least 16.54 dB when noise is added to the shifted signal with a step size of −5 dB,and the demodulation of the shifted signal post-noise reduction via the ZFFT algorithm is capable of completing the detection of the low frequency signals of the ZPW-2000 frequency shift signals. By comparing the empirical modal decomposition algorithm,wavelet threshold algorithm and other algorithms to deal with different SNR of frequency shift signals containing noise,it is verified that the optimized tri-stable stochastic resonance system has a larger output SNR,a better effect of noise reduction,and a good ability to anti-interference. The results provide a reference for realizing the reduction of the energy loss of the frequency shift signal while suppressing noise.
tri-stable stochastic resonanceZPW-2000 frequency shift signalscale varyingoutput signal-to-noise ratiosignal detection
万方数据
维普
