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从混沌伪码序列的产生机理出发,分别从量化混沌遥测信号检测、实值混沌遥测信号识别和混沌遥测系统参数估计方面分析了可供非合作者利用的特征和方法。提出了基于Duffing振子的混沌遥测信号检测方法,以及基于相空间重构的遥测信号识别方法和基于混沌同步的遥测系统参数估计方法。仿真分析表明所构造方法可以实现对混沌遥测信号的非合作分析。 相似文献
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一种新的间歇混沌信号Poincaré映像判别方法 总被引:2,自引:0,他引:2
针对混沌振子微弱信号检测中间歇混沌信号的判别问题,该文分析了噪声对Poincaré截面的扰动影响,提出一种基于Poincaré映像的新方法,并通过数值仿真对该方法进行了验证,结果表明在强噪声作用下,即使相空间分量输出波形难以进行判别,该方法仍然能够实现间歇混沌发生频率的有效判别,且抑制了混沌振子自发的短时间周期振荡现象,实现了强噪声背景下微弱周期信号的快速有效检测. 相似文献
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针对混沌振子微弱信号检测中间歇混沌信号的判别问题,该文分析了噪声对Poincaré截面的扰动影响,提出一种基于Poincaré映像的新方法,并通过数值仿真对该方法进行了验证,结果表明在强噪声作用下,即使相空间分量输出波形难以进行判别,该方法仍然能够实现间歇混沌发生频率的有效判别,且抑制了混沌振子自发的短时间周期振荡现象,实现了强噪声背景下微弱周期信号的快速有效检测. 相似文献
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针对混沌海杂波背景下的微弱信号检测问题,结合互补集成经验模态分解理论,提出了一种优化的核极限学习机微弱信号检测方法。采用互补集成经验模态分解法将混沌信号分解为一系列固有模态函数,通过核极限学习机对经相空间重构后的各模态函数分别建立预测模型,利用人工蜂群算法对核极限学习机的正则化系数和核参数进行优化,重构预测信号,从预测误差中检测出混沌海杂波背景中的微弱信号(瞬态信号与周期信号)。分别以Lorenz 系统和IPIX 雷达海杂波数据为例进行了仿真,并研究了不同强度的噪声对微弱信号检测的影响。结果表明:该方法可以有效地从混沌背景中检测出微弱目标信号,当系统不存在噪声时,Lorenz 系统得到的均方根误差0. 000 000 12 (-118. 959 1 dB)比传统极限学习机方法的均方根误差0. 001 345 08(-80. 154 7 dB)降低了4 个数量级;若SNR逸0 dB,噪声对微弱目标信号检测的影响可以忽略;但当SNR<-7 dB,则无法检测出微弱信号。 相似文献
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一种定量估计混沌信号中信噪比的方法 总被引:2,自引:0,他引:2
通过对混沌信号的相空间重构分析,建立了一个与信噪比极其相关的统计量:用信号标准差标准化后的重构吸引子中轨迹的平均分离距离.仿真试验结果显示,对较短的混沌时间序列,该统计量可以被用作定量估计被噪声污染的混沌信号的信噪比的一个工具。 相似文献
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针对混沌振子微弱信号检测中间歇混沌信号的判别问题,该文分析了噪声对Poincaré截面的扰动影响,提出一种基于Poincaré映像的新方法,并通过数值仿真对该方法进行了验证,结果表明在强噪声作用下,即使相空间分量输出波形难以进行判别,该方法仍然能够实现间歇混沌发生频率的有效判别,且抑制了混沌振子自发的短时间周期振荡现象,实现了强噪声背景下微弱周期信号的快速有效检测。 相似文献
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研究了实际采集的海杂波的关联维及最大Lyapunov指数。结果表明,海杂波具有混沌特性。基于复杂非线性系统的相空间重构理论和混沌信号可短期预测的特征,提出了强海杂波中的微弱目标信号检测的神经网络方法,给出了雷达检测的模型。 相似文献
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Study of features based on nonlinear dynamical modeling in ECG arrhythmia detection and classification 总被引:3,自引:0,他引:3
Owis MI Abou-Zied AH Youssef AB Kadah YM 《IEEE transactions on bio-medical engineering》2002,49(7):733-736
We present a study of the nonlinear dynamics of electrocardiogram (ECG) signals for arrhythmia characterization. The correlation dimension and largest Lyapunov exponent are used to model the chaotic nature of five different classes of ECG signals. The model parameters are evaluated for a large number of real ECG signals within each class and the results are reported. The presented algorithms allow automatic calculation of the features. The statistical analysis of the calculated features indicates that they differ significantly between normal heart rhythm and the different arrhythmia types and, hence, can be rather useful in ECG arrhythmia detection. On the other hand, the results indicate that the discrimination between different arrhythmia types is difficult using such features. The results of this work are supported by statistical analysis that provides a clear outline for the potential uses and limitations of these features. 相似文献
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利用混沌振子可以检测微弱的信号,并且具有很多优点。本文根据混沌微弱信号检测的原理,提出了将duffing混沌振子应用到三态脉冲位置调制信号检测中, 检测过程首先调节系统的策动力 ,使系统处于从混沌状态向大周期状态过渡的临界状态,此时系统的策动力阈值为 ,其相轨迹仍是混沌的,当三态脉冲信号加入系统后,系统从混沌态转变为大尺度周期状态,则检测出输入信号中包含有周期信号;如果系统继续处于混沌状态,则说明输入信号为纯噪声;最后通过相干提取包络识别系统状态,从而实现三态脉冲信号的检测。仿真结果表明了文中所提方法的可行性和有效性。 相似文献
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This paper is devoted to introduce a novel complex fifth-order memristive circuit system and its applications in synchronous stability and weak signal detection. Firstly, the typical dynamical behaviors of the memristive system are discussed by chaotic phase portrait, complexity analysis, one-parameter bifurcation and Lyapunov exponent spectrum. Secondly, the adaptive control method is applied to realize the synchronization between the drive memristive system (DMS) and the response memristive system (RMS). The results indicate that the synchronization method has strong robustness and anti-interference ability. Thirdly, the weak signal detection of the novel five-dimensional memristive system is realized by using the extreme sensitivity of chaotic system to initial values. Finally, the fifth-order memristive circuit is designed by using basic electronic elements and simulated by Multisim software. And the anti-interference ability and sensitivity of the fifth-order memristive circuit are further verified by adding different weak disturbance signals at different positions of the circuit. 相似文献
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Ma Hongguang Han Chongzhao Wang Guohua Xu Jianfeng Zhu Xiaofei 《电子科学学刊(英文版)》2005,22(6):605-611
This paper presents a fault-detection method based on the phase space reconstruction and data mining approaches for the complex electronic system. The approach for the phase space reconstruction of chaotic time series is a combination algorithm of multiple autocorrelation and Г-test, by which the quasi-optimal embedding dimension and time delay can be obtained. The data mining algorithm, which calculates the radius of gyration of unit-mass point around the centre of mass in the phase space, can distinguish the fault parameter from the chaotic time series output by the tested system. The experimental results depict that this fault detection method can correctly detect the fault phenomena of electronic system. 相似文献
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设计一个能够输出用于医学上的标准心电图信号,同时还能输出其他波形信号的发生器。在设计过程中,首先研究该发生器的设计要求,再对其硬件的各部分电路进行研究,最后对其软件的各部分程序进行研究。经过软件调试的结果完全达到其设计要求,可以满足各种心电图仪器的校准和维护的应用要求。 相似文献
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Jin Yu Yu-Dong Yao 《Wireless Communications, IEEE Transactions on》2005,4(2):390-396
Low probability of intercept (LPI) performance of a direct-sequence (DS) spread-spectrum (SS) system with chaotic spreading sequences is investigated in this paper. Several intercept receivers, including energy detectors, synchronous and asynchronous, coherent and noncoherent structures, which are typically used to detect binary DS SS signals, are examined here to detect the presence of chaotic DS SS signals. A simple detection approach using a binary correlating function to detect nonbinary chaotic sequences is proposed. The expressions of detection probabilities of chaotic spreading signals using those intercept receivers are derived. Comparisons between systems using chaotic and binary sequences are given in terms of the LPI performance, and the performance improvement with chaotic spreading sequences is observed. 相似文献
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合成孔径雷达(Synthetic Aperture Radar,SAR)通道对消技术可有效抑制散射波干扰等多种干扰类型,因此本文提出利用方位向间歇采样散射波干扰慢时间间歇性来对抗SAR双通道对消系统的干扰方法.首先详细推导了散射波干扰的SAR双通道对消原理,然后建立了方位向间歇采样散射波干扰模型并分析了该方法对传统SAR成像的干扰效果.在此基础上,分别研究了该干扰方法在双通道对消系统分别采用两种相位补偿条件时的对抗效果.理论与实验分析表明:当采用自动相位搜索算法估计相位进行补偿时,可使得场景对消成像出现类似噪声的混乱明暗斑点,并伴随着未对消的虚假散射场景;当采用准确相位进行补偿时,可在对消成像中形成多个虚假散射场景和对消暗条纹. 相似文献