双稳随机共振系统信号调制噪声效应用于弱信号检测

Effect of Signal Modulating Noise in Bi-Stable Stochastic Resonance Systems for Detecting Weak Signals

通过对双稳系统随机共振模型的数值分析 ,得出在双稳系统输出信号中 ,有一个正弦信号成分和一个表现为维纳过程的噪声成分分别与输入的正弦信号和白噪声相对应。通过选择合适的系统参数 ,可以减小系统输出中信号和噪声之间的耦合效应。该系统可以大大抑制噪声 ,并在双稳系统中产生信号调制噪声效应。然后对双稳系统的输出信号作功率谱分析。不但可以辨识出淹没在白噪声中的微弱正弦信号的频率 ,还可以较精确地估算出微弱正弦信号的幅值。数值仿真表明 ,双稳系统的信号调制噪声效应可用于多个微弱正弦信号的检测。

The application of the effect of signal modulating noise in bi-stable stochastic resonance systems is studied by the detection of weak sinusoidal signals. Numerical analyses have been made on the stochastic resonance model in bi-stable dynamical systems. The results show that a sinusoidal and a noise signals are used as the Wiener process corresponding to the input sinusoidal signal and the input white noise,respectively. When the system parameters are appropriately selected,the coupling effect between the sinusoidal signal and the white noise can be weakened and the noise can be suppressed,thus the effect of signal modulating noise can occur in the output. In this case the frequency and the magnitude of the weak sinusoidal signal submerged in the noise can be evaluated by an analysis on the power spectral density of the system output signal. Numerical simulation shows that the application is also effective on the detection of several weak sinusoidal signals submerged in the noise.