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硕士论文-混沌同步及在雷达中的应用研究，正文共76页。
【摘要】 混沌信号是一类内在确定外在类似随机性的特殊信号。与噪声相比,混沌信号是可控和可同步的。所以,混沌雷达既保留传统噪声雷达优点又克服了其无法控制的缺点,这使得混沌应用于雷达中具有更多的潜在优越性。但目前,传统混沌同步存在收敛速度不够理想和对系统参数变化非常敏感的缺点。此外,基于混沌同步的混沌雷达信号处理方法性能不理想。本文围绕上述问题展开了研究,主要工作归纳如下：(1)基于超混沌系统的非线性反馈同步和参数不敏感性研究对一类6阶超混沌系统进行非线性反馈同步设计。根据Hurwitz急定原理,设计非线性控制变量,使得误差方程雅可比矩阵的特征值实部均小于零,并使得特征值实部的绝对值较大。该算法比传统同步算法收敛速度快,并具有对系统参数比例系数不敏感的优点。(2)快速混沌同步算法研究给出了一种适用连续和离散混沌系统的快速混沌同步算法。根据Taylor展开式,设计控制变量,使得误差方程控制矩阵满足同步判定条件,进一步优选控制矩阵,仅需一步运算,便可快速同步。该算法收敛速度快,抗噪声能力强,具有更强的实际工程意义。(3)基于混沌同步的混沌雷达信号处理方法研究首先,对基于Colpitts系统进行新型测距算法研究。相比基于chuas系统的新型测距算法而言,本文算法具有更好的抗噪声性能和测距精度。其次,本文研究了基于混沌参数优化算法,优化后的信号更适合作为雷达发射信号。最后,本文给出一种基于混沌同步的新型测速算法,该算法具有强抗噪声能力。
【Abstract】 Chaos is a kind of special signal which is deterministic with noise-like characteristic. In comparison with the random signal, chaos can be controlled and synchronized. So chaotic radar preserves the advantages of traditional noise radar and overcomes the shortcoming beyond control, which affords chaos great potentials in chaotic radar. However, the convergence rate of traditional synchronization is slow, and the synchronization performances are very sensitive to variation of parameters. Besides, the performances of chaotic radar signal processing methods based on synchronization are not ideal.Focus on the issues mentioned above, main results are concluded as follows:(1) Study on synchronization and parameters insensitivity of hyperchaotic systems using nonlinear feedback controlSynchronization of a class of 6-order hyperchaotic systems using nonlinear feedback control is designed. According to Hurwitz stability theory, designing a nonlinear controller can make the real parts of the eigenvalues of the error equation’s Jacobian matrix negative. And the absolute values of the real of eigenvalues are larger, the convergence rate of synchronization is faster. Besides, it has the advantage of proportion parameters insensitivity.(2) Study on fast synchronization of chaosThe continuous and discrete chaotic systems for fast synchronization algorithms are proposed. According to Taylor expansion, nonlinear controller is designed to make error equation’s control matrix satisfy critical conditions for synchronization|and further to optimize the control matrix, so fast synchronization with only one step operation can be achieved. And the proposed algorithm has faster convergence rate, stronger anti-noise ability, and stronger engineering practice significance.(3) Study on chaotic radar signal processing methods based on synchronizationFirstly, this dissertation studies on a novel method of distance measurement based on colpitts chaotic system. And the proposed method has better noise robust ability and high ranging precision than that of chuas chaotic system. And in the second place, the optimized signal is more suitable for radar signal after using chaotic parameter optimization method. Finally, a novel method of velocity measurement based on chaos synchronization with strong anti-noise ability.
【关键词】 信号处理； 混沌雷达； 混沌同步； 参数不敏感性；
【Key words】 signal processing； chaotic radar； chaos synchronization； parameters insensitivity；