一种利用Duffing-Vanderpol振子估计弱信号相位的方法

Estimation of Weak Signal Phase by Using Duffing-Vanderpol Oscillator

根据Duffing-Vanderpol振子大周期态时的最大Lyapunov指数与系统策动力的关系,提出了一种基于该振子检测微弱信号相位参量的方法。该方法利用系统策动力与待测信号初始相位有关的特性,得到待测信号的初始相位,并将相位检测过程中噪声对系统的影响作为影响因子加以考虑。理论分析及数值仿真结果表明,该方法工程实现简单,抗噪性能好。当待测信号信噪比为-30d B时,均方误差仅为0.1,具有较高的估计精度。

When Duffing- Vanderpol oscillator is in large- scale periodic motion,there are some nexus between the largest Lyapunov exponent and system driving force. According to this conclusion,an algorithm for detecting weak signals' phase based on Duffing- Vanderpol oscillator is proposed. Through finding the relationship between system driving force and the phase of weak signal,the weak signals' phase is detected. The noise impact on system is also considered. Theoretical analysis and simulation result show that this algorithm is easy to be realized in engineering with strong restrain ability to noise and high estimation accuracy. When the signal- to- noise ratio( SNR) of to- be- detected signals is equal to- 30 d B,the mean- square error( MSE) is only 0. 1.