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We explore the collective response of an uncoupled parallel array of saturating dynamical subsystems to a noisy periodic or random signal. Numerical simulation results show that a parallel array of nonlinear saturating subsystems can enhance the signal transmission via tuning the internal noise intensity and increasing the array size. The input-output gain larger than unity, described by the signal-to-noise ratio for a periodic signal or the correlation coefficient for a random signal, is observed in a form of array stochastic resonance. This stochastic resonance phenomenon can be useful for practical information-processing systems. 相似文献
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线性调频信号是工程中常见的一种信号, 由于其为非周期信号, 无法以频域信噪比作为衡量其是否产生随机共振的测量手段, 故鲜有文献研究以线性调频信号为激励信号的随机共振现象. 本文利用线性调频信号在最优分数阶Fourier变换域上的能量聚集性, 首次提出以最优分数阶Fourier变换域上定义的信噪比作为测量手段, 研究了线性调频信号叠加高斯白噪声激励过阻尼双稳系统的随机共振现象, 且发现了以线性调频信号为激励信号时产生的新现象, 即随着信号频率的增大, 随机共振将逐渐减弱, 并给出了合理的解释.仿真的结果与理论分析一致, 验证了本文所提出方法的有效性.
关键词:
线性调频信号
分数阶Fourier变换
随机共振 相似文献
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We compare the stochastic resonance (SR) effects in parallel arrays of static and dynamical nonlinearities via the measure of output signal-to-noise ratio (SNR). For a received noisy periodic signal, parallel arrays of both static and dynamical nonlinearities can enhance the output SNR by optimizing the internal noise level. The static nonlinearity is easily implementable, while the dynamical nonlinearity has more parameters to be tuned, at the risk of not exploiting the beneficial role of internal noise components. It is of interest to note that, for an input signal buried in the external Laplacian noise, we show that the dynamical nonlinearity is superior to the static nonlinearity in obtaining a better output SNR. This characteristic is assumed to be closely associated with the kurtosis of noise distribution. 相似文献
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变步长随机共振算法有效解决了绝热近似大参数条件下的弱信号检测问题.基于信号近似熵测度的自适应随机共振,实现了变步长随机共振最优输出的自适应求解.周期信号的近似熵不受其幅值和相位变化的影响,而只与其频率及信噪比有关.因此,按照原始数据的采样条件,构造待检测频率在预定信噪比下的标准信号,并以其近似熵为基准,通过自动调节非线性系统的结构参数和计算步长,求得系统输出的近似熵距离矩阵.该矩阵中的最小值所对应的即为自适应条件下非线性动力系统的最优参数. 相似文献
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We investigate the effect of alpha stable noise on stochastic resonance in a single-threshold sensor system by analytic deduction and stochastic simulation. It is shown that stochastic resonance occurs in the threshold system in alpha stable noise environment, but the resonant effect becomes weakened as the alpha stable index decreases or the skewness parameter of alpha stable distribution increases. In particular, for Cauchy noise a nonlinear relation among the optimal noise deviation parameter, the signal amplitude and the threshold is analytically obtained and illustrated by using the extreme value condition for the output signal-to-noise ratio. The results presented in this communication should have application in signal detection and image restoration in the non-Gaussian noisy environment. 相似文献
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Chapeau-Blondeau F 《Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics》2000,61(1):940-943
A model is developed for a periodic signal corrupted by an arbitrarily distributed phase noise and transmitted by an arbitrary memoryless system. The model establishes a new form of the phenomenon of stochastic resonance, whereby signal transmission can be enhanced by addition of noise. This is revealed by the standard signal-to-noise ratio of stochastic resonance, which here receives an explicit theoretical expression, and which is shown improvable via noise addition. This model is the first to propose a theory of stochastic resonance with phase noise. It represents a unique framework for further investigations on stochastic resonance and its applications. 相似文献
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Stochastic resonance in a time-delayed asymmetric bistable system with mixed periodic signal
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This paper studies the phenomenon of stochastic resonance
in an asymmetric bistable system with time-delayed feedback and
mixed periodic signal by using the theory of signal-to-noise ratio
in the adiabatic limit. A general approximate Fokker--Planck
equation and the expression of the signal-to-noise ratio are derived
through the small time delay approximation at both fundamental
harmonics and mixed harmonics. The effects of the additive noise
intensity $Q$, multiplicative noise intensity $D$, static asymmetry
$r$ and delay time $\tau$ on the signal-to-noise ratio are
discussed. It is found that the higher mixed harmonics and the
static asymmetry $r$ can restrain stochastic resonance, and the
delay time $\tau $ can enhance stochastic resonance. Moreover, the
longer the delay time $\tau $ is, the larger the additive noise
intensity $Q$ and the multiplicative noise intensity $D$ are, when
the stochastic resonance appears. 相似文献
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We study characteristics of the output signal in a nonlinear monostable inertial dynamical system with the harmonic signal
and Gaussian white noise supplied additively to the input. Several types of monostable systems are examined, and analytical
expressions for the output-signal power amplification and signal-to-noise ratio are obtained for such systems for the first
time. The main attention is paid to the stochastic resonance and antiresonance phenomena, which manifest themselves as nonmonotonic
dependences of the mentioned characteristics on the input-noise intensity. In particular, it is shown for the first time that
the output signal-to-noise ratio may have a maximum as a function of the input-noise intensity in a monostable system. This
corresponds to the classical definition of stochastic resonance, which earlier was only observed in bistable (multistable)
systems.
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 51, No. 10, pp. 899–913, October 2008. 相似文献
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We study the stochastic resonance phenomenon in saturating dynamical models of neural signal transduction, at the synaptic stage, wherein the noise in multipathways enhances the processing of neuronal information integrated by excitatory and inhibitory synaptic currents. For an excitatory synaptic pathway, the additive intervention of an inhibitory pathway reduces the stochastic resonance effect. However, as the number of synaptic pathways increases, the signal transduction is greatly improved for parallel multipathways that feature both excitation and inhibition. The obtained results lead us to the realization that the collective property of inhibitory synapses assists neural signal transmission, and a parallel array of neurons can enhance their responses to multiple synaptic currents by adjusting the contributions of excitatory and inhibitory currents. 相似文献
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Stochastic resonance system is an effective method to extract weak signal.However,system output is directly influenced by system parameters.Aiming at this,the Levy noise is combined with a tri-stable stochastic resonance system.The average signal-to-noise ratio gain is regarded as an index to measure the stochastic resonance phenomenon.The characteristics of tri-stable stochastic resonance under Levy noise is analyzed in depth.First,the method of generating Levy noise,the effect of tri-stable system parameters on the potential function and corresponding potential force are presented in detail.Then,the effects of tri-stable system parameters w,a,b,and Levy noise intensity amplification factor D on the resonant output can be explored with different Levy noises.Finally,the tri-stable stochastic resonance system is applied to the bearing fault detection.Simulation results show that the stochastic resonance phenomenon can be induced by tuning the system parameters w,a,and b under different distributions of Levy noise,then the weak signal can be detected.The parameter intervals which can induce stochastic resonances are approximately equal.Moreover,by adjusting the intensity amplification factor D of Levy noise,the stochastic resonances can happen similarly.In bearing fault detection,the detection effect of the tri-stable stochastic resonance system is superior to the bistable stochastic resonance system. 相似文献
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Stochastic resonance in a single-mode laser driven by quadratic pump noise and amplitude-modulated signal 总被引:1,自引:0,他引:1
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This paper investigates the phenomenon of stochastic resonance in a
single-mode laser driven by quadratic pump noise and
amplitude-modulated signal. A new linear approximation approach is
advanced to calculate the signal-to-noise ratio. In the linear
approximation only the drift term is linearized, the multiplicative
noise term is unchangeable. It is found that there appears not only
the standard form of stochastic resonance but also the broad sense
of stochastic resonance, especially stochastic multiresonance
appears in the curve of signal-to-noise ratio as a function of
coupling strength λ between the real and imaginary parts of
the pump noise. 相似文献