共查询到17条相似文献,搜索用时 109 毫秒
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基于单涡卷混沌Colpitts振荡器模型,提出了一种网格多涡卷混沌Colpitts振荡器模型。利用阶跃函数代替单涡卷混沌Colpitts振荡器模型中的非线性函数,以及增加一个饱和函数,构造了一个能产生网格多涡卷混沌吸引子的Colpitts振荡器模型。通过数值仿真与电路实验,验证了该网格多涡卷混沌Colpitts振荡器的可行性。 相似文献
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宽带混沌信号拥有良好的相关特性、低截获概率和高保密性等优点.本文介绍了一种基本的混沌信号产生电路-Colpitts振荡电路,在此基础上,对该电路作了相关改进,同时通过仿真对它们的性能进行了分析比较.结果显示:对三阶Colpitts振荡电路的改进方法是可行的;三阶Colpitts振荡电路频谱较为集中,且自相关性能差,应用... 相似文献
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以Colpitts振荡器电路为例,在建立Colpitts电路模型的基础上,对其进行PSpice仿真研究,观察状态变量分别在时域和频域中的变化.通过调整电路元件的参数,观察Colpitts电路中动力学行为的演变过程,得到了与理论分析相吻合的结果.可以发现,电路处于混沌态和准周期态的参数组合不是唯一的. 相似文献
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介绍了一种新的方法实现对Colpitts混沌信号的产生,该系统是基于虚拟仪器平台并结合MATLAB计算模块实现对Colpitts混沌信号的产生,同时对混沌信号的自相关和功率谱进行分析。并通过USB-6009采集模块外扩高速DAC(数模转换器)芯片AD5405实现对Colpitts混沌信号的单通道输出。系统可根据用户的需求调节参数,实现不同频率混沌信号的产生。结果证明,该发生器结构简单,操作方便,运行稳定可靠,有一定参考和实用价值。 相似文献
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构建新的整数阶三维细胞神经网络系统,通过对其非线性动力学分析、数值计算与电路仿真,验证了该系统混沌吸引子的存在性及物理上的可实现性。同时通过调节线性参数b,研究了新的细胞神经网络系统在基于分数阶qi(i=1,2,3)不同组合条件下所表现出的混沌特性。结合分数阶电路理论分析分数阶电路中各单元电路形式,并设计了相应参数b可变、阶数值qi可切换的分数阶细胞神经网络电路系统。经统计本设计可实现13824种多元组合电路,并选取具有代表性组合电路进行电路仿真。仿真结果表明,多元电路仿真和数值仿真具有相似的混沌相图,从而证实了细胞神经网络在分数阶条件下仍表现出丰富的动力学特性,具有灵活实用价值和现实推广意义。 相似文献
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通过虚拟电子实验室EWB软件仿真了非线性系统产生的混沌现象,以Colpitts振荡器电路为例,讨论了在电路中设置不同的元件参数值时产生的不同混沌,并介绍了这种动态混沌在通信系统中作为信息载体的重要应用. 相似文献
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非理想信道下Colpitts混沌电路的自适应同步研究 总被引:1,自引:0,他引:1
本文研究了Colpitts混沌电路在非理想信道条件下的自适应同步问题。引入自适应控制器对输入到响应部分(response system)的衰变混沌信号进行预处理,来补偿衰落信道对于同步性能的影响。给出了系统的数学模型,对恒定信道衰变和时变信道衰变两种非理想信道条件下的混沌ColpiRs电路的自适应同步进行了数值仿真研究。仿真结果表明,对于恒定或慢变化的时变信道衰变,自适应控制器可以有效的提高Colpitts电路响应部分和驱动部分(Drive system)的同步性能。 相似文献
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Zhiguo Shi Songjie Bi Hongtao Zhang Rongxing Lu Xuemin Shen 《Wireless Communications and Mobile Computing》2015,15(10):1456-1470
In this paper, we propose a synchronization scheme based on an improved auxiliary particle filter (IAPF) for chaotic Colpitts circuit and conduct an experimental study on the synchronization performance with application to secure communications. Specifically, with the synchronization scheme, when the chaotic signals generated by an analog Colpitts circuit are transmitted through a nonideal channel, the distorted signals are processed digitally by the novelly designed IAPF at the receiver, in order to obtain the synchronized signals of the transmitter circuit. Experimental results indicate that synchronization can be achieved over both the additive white Gaussian noise channel and the multipath fading channel with low signal‐to‐noise ratio, even if there exist severe circuit parameter mismatches between the transmitter and the receiver. Furthermore, a chaos‐masking secure communication system is constructed and verified over both the additive white Gaussian noise channel and the multipath fading channel, and the bit error rate is evaluated versus different signal‐to‐noise ratios and symbol periods. It is shown that the achievable bit error rate can reach the order of magnitude of 10 − 4 without error correction coding techniques. In addition, security analysis demonstrates that the proposed chaotic secure communication system is resistant to the brute‐force attack. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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Particle Filter-Based Synchronization of Chaotic Colpitts Circuits Combating AWGN Channel Distortion
Zhi-Guo Shi Shao-Hua Hong Ji-Ming Chen Kang-Sheng Chen You-Xian Sun 《Circuits, Systems, and Signal Processing》2008,27(6):833-845
In this paper, synchronization of chaotic Colpitts circuits using a particle filter (PF) to combat the additive white Gaussian
noise (AWGN) channel effect is studied by numeric simulations. A novel PF algorithm suitable for chaos synchronization is
proposed. With this algorithm, chaos synchronization of Colpitts circuits can be achieved and maintained in AWGN channels.
Parameters in the proposed PF algorithm are studied to understand their effects on synchronization performance. The synchronization
performance using the proposed PF algorithm is compared with those using other digital filters, such as the extended Kalman
filter and the generic PF. It is found that the proposed PF algorithm performs better than the other digital filters. Simulation
results also show that the particle number is not very critical to the synchronization performance when this PF algorithm
is used. 相似文献
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针对某些雷达、通信等系统在应用中对混沌信号频域带宽的要求,设计了一种基于考毕兹振荡器电路的宽带混沌信号发生器。该混沌信号产生电路由考毕兹振荡器为基本谐振电路、级联若干容阻串并联单元的选频网络构成,混沌信号的上下限频率分别由基本谐振电路和第一节容阻串并联网络参数决定,通带频谱的平坦性受其他级联选频网络影响。根据初步分析和仿真试验,该混沌电路组成结构简单,能够产生带宽超过60MHz较为平坦的宽带混沌信号。 相似文献
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Shi Zhiguo Ran Lixin Chen Kangsheng 《电子科学学刊(英文版)》2006,23(3):433-436
Chaotic Colpitts circuits with fundamental frequency f^* beyond 1GHz are studied by both circuit simulation and experiment using Philips' broadband transistor with threshold frequency of 25GHz. For the basic configuration of Colpitts circuit with f^* of about 1,6GHz, broadband continuous power spectra could be obtained from both circuit simulations and experiments. The harmonics of the observed signal from Agilent PSA/ESA spectrum analyzer are as noticeable as far as 12GHz. A modified Colpitts circuit structure employing the parasitic inductance of BJT (Bipolar Junction Transistor) is also proposed and investigated. By circuit simulation, chaotic attractor and broadband continuous power spectra could be obtained from the modified Colpitts circuit with f^* of about 3.5GHz. Because the parasitic effects of the prototype board, the experiment result of the modified Colpitts circuit does not agree well with the simulation result. The gap between the simulation and experimental result could be bridged by replacing the lumped circuit elements with distributed ones. 相似文献
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Based on the framework of Colpitts oscillator, a four-dimensional multi-scroll hyperchaotic system is proposed, which generates
(2M+1)×(2N+1)-scroll chaotic and hyperchaotic attractors. The key strategy is to increase the number of index-2 equilibrium points by
introducing two unit saw-tooth functions to extend and modify the Colpitts oscillator model. By using bifurcation diagram
and phase portrait, the dynamical characteristics of the multi-scroll hyperchaotic system are briefly studied. Moreover, micro-controller
based circuit realization is introduced and the experimental results demonstrate that 7×5-scroll chaotic and hyperchaotic
attractors can be obtained in the digital circuit. 相似文献