【摘要】 对Duffing非线性动力学系统的输出状态发生改变时需满足的条件进行了分析,将相轨迹是否发生变化作为系统输出状态改变的判定依据,提出了一种低信噪比情况下微弱正弦信号幅度和相位的检测方法;仿真结果表明,信噪比为-20dB时,幅度检测的均方误差约为3％,相位检测的均方误差约为3°;该方法还具有幅度检测门限值低的特点,可对幅度为10-3级以下的信号进行检测。更多还原

【Abstract】 The condition needed for output state transformation of Duffing nonlinear dynamic system is analyzed, determining output state transformation according to change of the phase trace, a method to estimate amplitude and phase of weak sine signals in low signal to noise ratio CSNR) condition is proposed, simulation results show that; when SNR= - 20dB, the root mean error of amplitude detection approximately is 3% and the root mean error of phase detection approximately is 3°. This method also has characteristic of low amplitude detection threshold, it can detect weak signals with amplitude value smaller than 10-3 level.更多还原