共查询到20条相似文献,搜索用时 187 毫秒
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提出一种新的混沌调制通信方法.利用一个自适应控制器跟踪信息信号的误差对产生混沌载波的发射系统进行参数调制.同时,信息信号直接与混沌载波相乘作为发射信号驱动接收系统.在接收端,另一个自适应控制器维持收发系统的混沌同步并恢复出信息信号.由于同步误差与信息信号无关,从而实现了大幅度、快时变信息信号的混沌调制通信.理论分析和数值模拟的结果表明该方法增强了低维混沌系统的通信保密性.
关键词:
混沌调制
保密通信
自适应控制器
蔡氏电路 相似文献
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分析了一个新的复杂的四维混沌系统的基本特性,该系统每个方程中包含一个三次交叉乘积项,共有9个平衡点,它们相对于原点和坐标轴具有完美的对称性,并且相对于线性特性和不变流形具有很好的相似性.描述了两个同时共存的对称双翼吸引子.最后,设计了一个模拟电路来实现这个新的四维混沌系统,表明数值仿真和电路实现具有很好的一致性,同时说明在应用上由于频率不同导致的仿真与物理实现之间的重要区别.
关键词:
四维混沌系统
Lyapunov 指数
共存双翼吸引子
电路实现 相似文献
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提出混沌通信中继器设想,建立半导体激光器激光混沌全光中继器物理模型,理论证明了激光混沌中继器系统的同步.数值实现了发射系统、中继器系统、接收系统的混沌同步,分析了系统反馈系数和同步误差以及同步时间的关系.模拟了中继器系统在激光混沌保密通信中的应用,分别给出了具有正弦信号调制频率0.2GHz和数字信号0.2Gb/s速率的混沌通信以及同步误差分析,表明混沌中继器系统确能改善和提高激光混沌通信的解码质量.分析了中继器系统的带宽和20Gb/s高速率数字信号混沌通信以及同步误差,给出了具有正弦信号调制频率0.1—2
关键词:
混沌
同步
激光器
中继器 相似文献
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忆阻器是一种具有记忆功能和纳米级尺寸的非线性元件, 作为混沌系统的非线性部分, 能够使系统的物理尺寸大大减小, 同时可以得到各种丰富的非线性曲线, 提高混沌系统的复杂度和信号的随机性. 因此, 本文采用离子迁移忆阻器的磁控模型设计了一个新的混沌系统. 通过理论推导、数值仿真、Lyapunov指数谱、分岔图和Poincaré截面图研究了系统的基本动力学特性, 并分析了改变不同参数时系统动力学行为的变化. 同时, 建立了模拟该系统的SPICE电路, SPICE仿真结果与数值分析相符, 从而验证该混沌系统的混沌产生能力. 最后, 利用线性反馈同步控制方法实现了新构造的离子迁移忆阻混沌系统的同步, 并且采用该同步方法有效实现了语音信号的保密通信. 数值仿真证实了新混沌系统的存在性以及同步控制应用的可行性. 相似文献
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研究注入半导体激光混沌调制解调及其性能特性,提出外部光注入半导体激光器混沌内部相位编码方法. 小信号调制分析了系统混沌调制响应函数和解调响应函数以及解调因子,系统的调制解调响应函数以及解调因子在60MHz有一个峰值,系统在高频调制时,响应函数和解调因子明显下降. 理论推导出混沌调制解调方程,给出了小信号调制时的信息信号的解,数值分析出系统在低频有一个调制解调峰值,高频调制解调效果下降,但系统仍可以进行109Hz频率调制解调. 数值模拟并证明了系统在较大的参数范围内都能实现同步,模拟了混沌调制速率200Mb/s和调制频率1.4GHz的保密通信应用. 还通过键控调制注入光的相位相移对激光混沌态进行了编码,通过同步与非同步进行混沌解码,数值模拟了具有调制速率10Mb/s的混沌相位键控编码通信应用.
关键词:
混沌
同步
激光器
相位 相似文献
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基于提出的恒Lyapunov指数谱混沌系统,通过将系统中的参数进行剥离,得到一个改进型的恒Lyapunov指数谱混沌系统.该混沌系统存在三个重要的特性:双参数恒Lyapunov指数谱、存在全局线性调幅参数和倒相参数.通过Lyapunov指数谱与分岔图结合理论证明与推理,揭示了该新系统存在的上述动力学特征.构建实验电路,实现了改进混沌系统,物理实验验证了新系统的混沌行为.最后,利用单变量反馈控制方法实现了新系统的同步控制,通过物理实验验证了新系统同步控制的条件.
关键词:
改进恒Lyapunov指数谱混沌系统
电路实现
同步控制 相似文献
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In this paper, a new chaotic system without linear term is presented by ordinary differential equations, and some basic dynamical properties are studied. Moreover, the impulsive synchronization problem of the new chaotic systems is investigated by using uncertain impulsive control matrix. Using the impulsive theory, sufficient conditions are derived for the synchronization of new chaotic systems. Numerical simulation example is provided to verify the effectiveness of the proposed approach. 相似文献
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提出了一类新的具有切换与内同步特性的关联混沌系统, 该系统即可在同维系统间切换, 也可在不同维系统间切换, 当系统切换为四维系统后, 还可实现系统变量间的同步. 通过理论推导、数值仿真、 Lyapunov维数、Lyapunov指数谱研究了其基本动力学特性与内同步机理. 最后, 设计了该切换混沌系统的硬件电路并运用Multisim软件对该混沌系 统及其内同步特性进行了仿真实现, 数值仿真和电路仿真证实了该切换混沌系统物理可实现, 系统具有丰富的动力学特性.
关键词:
关联混沌系统
Lyapunov指数
切换
内同步 相似文献
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In this paper, a new numerical simulation approach is proposed for the
study of open-loop frequency response of a chaotic masking system. Using
Chua's circuit and the Lorenz system as illustrative examples, we have shown
that one can employ chaos synchronization to separate the feedback network
from a chaotic masking system, and then use numerical simulation to obtain
the open-loop synchronization response, the phase response, and the
amplitude response of a chaotic masking system. Based on the analysis of the
frequency response, we have also proved that changing the amplitude of the
exciting (input) signal within normal working domain does not influence the
frequency response of the chaotic masking system. The new numerical
simulation method developed in this paper can be extended to consider the
open-loop frequency response of other systems described by differential or
difference equations. 相似文献
15.
Chaos in fractional-order generalized Lorenz system and its synchronization circuit simulation 总被引:1,自引:0,他引:1 下载免费PDF全文
The chaotic behaviours of a fractional-order generalized Lorenz
system and its synchronization are studied in this paper. A new
electronic circuit unit to realize fractional-order operator is
proposed. According to the circuit unit, an electronic circuit is
designed to realize a 3.8-order generalized Lorenz chaotic system.
Furthermore, synchronization between two fractional-order systems is
achieved by utilizing a single-variable feedback method. Circuit
experiment simulation results verify the effectiveness of the
proposed scheme. 相似文献
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This research paper introduces a novel three-dimensional autonomous system, whose dynamics support periodic and chaotic butterfly attractors as certain parameters vary. A special case of this system, exhibiting reflectional symmetry, is amenable to analytical and numerical analysis. Qualitative properties of the new chaotic system are discussed in detail. Adaptive control laws are derived to achieve global chaotic synchronization of the new chaotic system with unknown parameters. Furthermore, a novel electronic circuit realization of the new chaotic system is presented, examined and realized using Orcad-PSpice program and physical components. The proposed novel butterfly chaotic attractor is very useful for the deliberate generation of chaos in applications. 相似文献
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In this paper the synchronization of fractional-order chaotic systems is studied and a new single state fractional-order chaotic controller for chaos synchronization is presented based on the Lyapunov stability theory. The proposed synchronized method can apply to an arbitrary three-dimensional fractional chaotic system whether the system is incommensurate or commensurate. This approach is universal, simple and theoretically rigorous. Numerical simulations of several fractional-order chaotic systems demonstrate the universality and the effectiveness of the proposed method. 相似文献
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This paper deals with the problem of synchronization for a class of uncertain chaotic systems.The uncertainties under consideration are assumed to be Lipschitz-like nonlinearity in tracking error,with unknown growth rate.A logic-based switching mechanism is presented for tracking a smooth orbit that can be a limit cycle or a chaotic orbit of another system.Based on the Lyapunov approach,the adaptation law is determined to tune the controller gain vector online according to the possible nonlinearities.To demonstrate the efficiency of the proposed scheme,the well-known chaotic system namely Chua’s circuit is considered as an illustrative example. 相似文献