混沌振子与随机共振双系统联合微弱信号检测方法研究

The Study for the Method to Weak Signal Detec- tion Based on the Combination of the Chaotic Ocillator System and Stochastic Resonance System

针对Duffing系统检测未知信号时需要待测周期信号频率先验值的不足，提出了一种混沌理论与随机共振理论相结合的信号检测方法。该方法首先利用随机共振系统对信号进行检测与频率值估计，然后再通过混沌系统进行频率值的选择与幅值估计。对于两个系统结合时涉及到的幅值数量级范围不同的问题，提出了信号预处理方法，有效扩大了混沌系统检测与提取信号的范围，并提高了双系统结合时的信号检测精度。仿真实验结果表明，所提出方法不仅可以精确、快速的提取出高斯白噪声下的未知微弱周期信号，而且扩大了Duffing系统和随机共振系统的有效检测范围，提高了其实用性。

The paper presents a method, which combines chaos theory with stochastic resonance theory, to evaluate weak periodic signal of unknown frequency in the heavy noise background. The method overcomes the disadvantage of the requirement of the frequency value of periodic signal when detection with Dujfing chaotic system. Firstly, the stochastic resonance theory is used to evaluate the frequency of the signal to be measured. Secondly, the Duffing chaotic system is used to extract the frequency of the signal and evaluate the amplitude of the signal. To fulfill the matching problem of amplitude orders of magnitude of the signal between the DuJfing chaotic system and the Stochastic resonance system, the method of the signal preprocessing are proposed, which not only enlarges the range of the frequency and amplitude of the detection signal, but also improves its detection accuracy. The simulation results show that the presented method can extract weak periodic signal under the background of Gaussian white noise with a very high accuracy and a fast speed, and meanwhile greatly expands the signal detection range and effectively improve the practicality of the Duffing chaotic systems and the Stochastic resonance system.