基于广义随机共振的Chirp信号检测性能分析

发布时间：2019-05-23 18:37

【摘要】：为便于提取多个chirp信号叠加噪声模型中目标chirp信号的参数信息,研究了该混合信号激励过阻尼双稳系统的随机共振现象。由于chirp信号在频域能量的非聚焦性,传统刻画随机共振的信噪比指标失效。因此,基于chirp信号在分数阶傅里叶变换域上的能量分布特性,对非线性随机动力系统的畸变输出信号进行变换域上的最优滤波,给出最优分数阶傅里叶变换域上的信干比定义形式,并以此作为目标chirp信号经过系统后的性能增益的度量和广义随机共振现象的判别依据。数值仿真结果表明,在存在多个chirp信号驱动的过阻尼双稳系统中,当目标chirp信号或噪声能量不足以激发粒子跃迁时,干扰chirp信号能在一定程度上协助粒子发生跃迁,产生协同随机共振现象,从而提高对目标chirp信号的检测性能。
[Abstract]:In order to extract the parameter information of target chirp signal in multiple chirp signal superposition noise model, the stochastic resonance phenomenon of overdamped bistable system excited by the mixed signal is studied. Because of the non-focusing of chirp signal in frequency domain, the signal-to-noise ratio (SNR) index of stochastic resonance is invalid. Therefore, based on the energy distribution characteristics of the chirp signal in the fractional Fourier transform domain, the distorted output signal of the nonlinear stochastic dynamic system is optimally filtered in the transform domain. In this paper, the definition of signal-to-interference ratio over the optimal fractional Fourier transform domain is given, which is used as the measure of the performance gain of the target chirp signal after the system and the discriminant basis of the generalized stochastic resonance phenomenon. The numerical simulation results show that in the over-damped bistable system driven by multiple chirp signals, when the target chirp signal or noise energy is not enough to excite the particle transition, the interference chirp signal can assist the particle transition to a certain extent. The cooperative stochastic resonance phenomenon is produced to improve the detection performance of the target chirp signal.
【作者单位】：四川大学数学学院;四川师范大学数学与软件科学学院;西南交通大学数学学院;
【基金】：国家自然科学基金青年科学基金资助项目(11301360) 高等学校博士学科点专项科研基金资助项目(20120181120089) 四川省教育厅重点项目资助(12ZA137)
【分类号】：TN911.23

【参考文献】