共查询到19条相似文献,搜索用时 125 毫秒
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该文提出一种新的混沌信号降噪方法——微扰法,并且给出了微扰法的一个具体实例算法——梯度微扰法。该文还对用梯度微扰法进行混沌信号降噪的效果进行了实验研究。实验结果表明,梯度微扰法能够在低信噪比时得到很好的降噪效果。文中还对梯度微扰法的参数选择问题进行了实验研究。 相似文献
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一种新的含噪混沌信号降噪算法 总被引:4,自引:1,他引:3
该文针对低信噪比、非高斯加性噪声和混沌动力学系统参数未知的含噪混沌信号降噪问题,提出了一种基于粒子滤波(Particle Filtering, PF)的降噪新算法。该算法将混沌信号和动力学系统中的未知参数作为一个多维状态矢量,利用PF方法递推计算多维状态矢量的联合后验概率分布,进而实现了对混沌信号的最优估计。对于混沌信号轨道分离过快所导致的退化问题,提出了有效的解决方法,并利用核平滑和自回归(Auto-Regression, AR)模型建模的方法分别实现了非时变以及时变参数的递推估计。仿真实验的结果表明,与现有的降噪方法相比,该文提出的新算法能够更加有效地抑制含噪混沌信号中的加性噪声。 相似文献
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提升小波变换用于混沌信号降噪具有良好的效果,阈值选取与混沌信号降噪后信号的畸变具有紧密联系。为了提高混沌信号中提升小波的自适应能力,降低降噪后信号的畸变率,提出了一种基于提升小波和粒子群相结合的混沌信号降噪方法。该方法在对提升小波变换后的细节部分进行阈值处理时,采用阈值自适应选择方法,并结合粒子群算法全局搜索最优阈值。通过对Colpitts模型进行仿真分析,与标准的软阈值降噪相比,能更好地对混沌信号降噪,并且降噪后信号失真度较小,具有很好的应用价值。 相似文献
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混沌调频雷达成像仿真 总被引:1,自引:0,他引:1
混沌调频信号类似随机信号,具有较强的抗干扰性能(ECCM)。为了提高成像雷达的抗干扰性能,该文把混沌调频信号用于成像雷达系统,使用n-Way Bernoulli映射产生混沌序列,用该混沌序列进行频率调制得到的信号具有良好的自相关特性,不但可以获得高分辨率雷达图像,还使雷达波形难于辨识。该文分析了信号模型,对点目标进行了仿真,分析了脉冲压缩波形的旁瓣特性。结果表明,混沌调频信号用于成像雷达系统可获得比较理想的点目标图像,在成像雷达系统中有良好的应用前景。 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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Xiang Zheng Zhang Taiyi Sun Jiancheng 《电子科学学刊(英文版)》2006,23(6):926-928
A new strategy for noise reduction of fast fading channel is presented. Firstly, more information is acquired utilizing the reconstructed embedding phase space. Then, based on the Recurrent Least Squares Support Vector Machines (RLS-SVM), noise reduction of the fast fading channel is realized. This filtering technique does not make use of the spectral contents of the signal. Based on the stability and the fractal of the chaotic attractor, the RLS-SVM algorithm is a better candidate for the nonlinear time series noise-reduction. The simulation results shows that better noise-reduction performance is acquired when the signal to noise ratio is 12dB. 相似文献
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《Optical Fiber Technology》2013,19(2):93-108
In this paper, network synchronization of coupled Chua’s circuits in star configuration is experimentally studied. In particular, plastic optical fiber (POF) is used in the network like communication channels among chaotic nodes to achieve synchronization. The master signal is sent to multiple slaves through a fiber optical coupler with corresponding electrical/optical and optical/electrical stages. An application to encrypted chaotic communication to transmit analogical signal and image messages to multiple receivers is also given. 相似文献
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E. V. Kalyanov B. E. Kyarginskii 《Journal of Communications Technology and Electronics》2010,55(9):1017-1023
A mathematical model illustrating the method for masking regular oscillations in a transmitter is considered. The method is
based on mixing these oscillations with chaotic motions formed from pulse chaotic oscillations with the use of the delay effect.
Separation of the transmitted signal in a subtractor is also based on the delay effect. Results of numerical analysis are
presented. It is shown that the proposed method of transmission and separation of the useful signal provides for the application
of developed chaotic oscillations for masking. Transmission of a masked regular signal is experimentally demonstrated in the
decimeter wavelength range. Transistor-coupled oscillators with chaotic dynamics are used for generation of noise-like oscillations.
Results of experimental studies on formation of continuous noise-like oscillations from pulse noise on the basis of the delay
effect are presented for the case when one of the two series of pulses contains the transmitted regular signal. Oscillation
filtering is used along with the delay effect for separation of useful oscillations. 相似文献
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本文提出一种基于混沌信号特性的信号盲提取算法,由于不同的混沌信号在相空间里面对应着不同的吸引子二阶增长率,利用这个特点定义了增殖系数(Proliferation Exponent,PE)并将其作为混沌信号提取的目标函数.首先分析基于增殖系数的梯度搜索方法在解决盲提取问题时存在不足,并将混沌信号的盲提取问题转化为带约束的优化问题,提出利用改进的粒子群优化算法解决信号盲提取的优化问题,通过惯性系数动态调整和最优位置的扰动,提高算法的寻优性能.实验结果表明基于增殖系数的信号提取算法能有效地提取混沌信号,提取的信号在时域和相空间与源信号接近,同时算法也表现出对噪声污染的鲁棒性. 相似文献
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Yu. A. Dmitriev A. V. Klevtsov 《Journal of Communications Technology and Electronics》2011,56(6):663-669
The problem of positioning with the use of ultra-wideband chaotic radio pulses is considered. A method for determination of
the difference of signal arrival times based on the cross-correlation function of the envelope of chaotic radio pulses is
proposed and studied. It is demonstrated that this method provides an error of estimation of the difference of signal arrival
times that is inverse proportional to the frequency band of the radio-pulse envelope. It is found that the noise stability
of the method is improved with as the suration of the chaotic radio pulse increases. 相似文献
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Enhancing the Bandwidth of the Optical Chaotic Signal Generated by a Semiconductor Laser With Optical Feedback 总被引:2,自引:0,他引:2
《Photonics Technology Letters, IEEE》2008,20(19):1633-1635