针对双稳随机共振输出波形失真的问题,从还原粒子运动轨迹的角度提出了波形恢复公式.通过将其应用于双稳系统对无噪阈上信号的响应输出,揭示了由粒子跃迁经过系统拐点引起的轨迹突变,及其在恢复波形的表现形式.鉴于阈下随机共振系统中噪声的随机影响,引入级联双稳系统对残余噪声进行二次调节,同时采用参数调节的恢复系统对波形进行恢复.数值仿真表明,该法直接应用于系统输出,适合处理有限长的时间数据,可以有效地估计噪声背景下微弱信号的时域波形.
This paper deals with the problem of the waveform distortion in the output of a stochastic resonance (SR) system. The formula of the waveform recovery is developed with the observations on the movement track of a particle in the bistable system and the recovery system. The pulse distortion induced by the particle's transition is investigated. With the stochastic influence of the noise in subthreshold SR, a cascaded-bistable system was introduced to generate the second tuning for the residual noise and the recovery system with the parametric tuning was applied to restore the output waveform. The numerical results showed that this method is available in the output signal with limited time data and in the waveform recovery containing weak signal in noise.