【作者】 张军；

【导师】 陈利民； 余峰；

【作者基本信息】 南昌大学 ， 电子与通信工程（专业学位）， 2015， 硕士

【摘要】 混沌扩频作为一门新兴学科,越来越多的学者对其进行了研究,并被广泛应用于扩频通信技术当中。本文对基带混沌扩频信号的特性进行了深入分析,并针对混沌信号最小相空间体积特性在混沌系统预失真技术,抗干扰技术方面做了进一步的研究。本文的主要研究成果及创新之处有:(1)研究了混沌扩频信号的特性。以logistic映射作为混沌信号的代表,用实验仿真的方法验证了混沌信号相对于随机噪声表现出最小相空间体积(Minimum Phase Space Volume)特性,且该特性受基带调制影响较小。验证了混沌信号具有正李雅普诺夫指数和混沌映射有一个或多个收敛点,在构造混沌扩频序列时应避免这些收敛点。(2)研究了最小相空间体积(MPSV)在滤除窄带干扰方面的应用。主要研究了单音干扰抑制模型,设计了一种基于二阶段动态干扰算法的单音干扰抑制滤波器。基本原理是将接收信号通过一逆滤波器,当输出信号具有最小相空间体积时,滤波器系数与干扰模型一致。仿真结果表明:当输入信噪比在15-0 db时,该算法信干噪比增益改善在18-4 db,能较好的滤除单音干扰信号。(3)研究了最小相空间体积(MPSV)在预失真技术中的应用。主要研究了如何将MPSV与预失真技术相融合,构造了一种基于MPSV的MBPSV(Minimum Bit Phase Space Volume)测度,使其更好应用于混沌扩频系统及其逆系统辨识。其基本思想是设计一预失真器,当功放的输出信号在有限维的比特相空间体积最小时,其与输入信号呈线性关系,预失真器恰好能预补偿功放的非线性失真。经仿真验证,该算法辨识的预失真器抑制非线性失真分量在11dB以上.更多还原

【Abstract】 As a new discipline, Chaos spread-spectrum communication has become a hotspot in the field of chaotic application research. In this paper, we focus on the characteristics of the chaotic spread spectrum signal in baseband, And do further research.in predistortion technology and anti-jamming technology with the minimum phase space volume properties of chaotic systems.The main research results and innovations of this paper are:(1)The first part focuses on the characteristics of the chaotic spread spectrum signal. this part mainly studied the most common chaotic map-logistic mapping,simulation results show that, relative to random noise, chaotic signal have the smallest volume of the phase space, and the characteristics is not affected by the basic modulation; Verify the chaotic signal has a positive Lyapunov exponent and Chaos mapping have one or more convergence point, and we should avoid these convergence points in Constructing the chaotic sequence.(2)The second part we discuss how to filter the narrowband interference with MPSV. we Study the tone interference suppression model, design a tone interference suppression filters based on two-stage dynamic algorithm tone interference.We let accept signal through an inverse filter, when the output signal has a minimum phase space volume, the interference filter coefficients consistent with the model. We did experiment with matlab simulation, when the input signal to noise ratio at the 0-15 db,the algorithm get about between 4-18 db gain.can be Better to filter out the interference signal tone.(3)In third part, we mainly research how to apply MPSV to predistortion technology. propose a MBPSV measure based on MPSV, which is applied to make it better in chaotic spread spectrum systems and its inverse system identification. The basic idea is to design a predistorter, when the output signal of the amplifier have the finite-dimensional phase space volume, the power amplifier nonlinear distortion is compensated by pre-predistortion. The output signal is linear witn the input. The simulation shows that the algorithm identification predistorter nonlinear distortion component is suppressed more than 11 dB.更多还原