几种新扩频码的构造及其性能分析

发布时间：2018-01-07 09:32

本文关键词：几种新扩频码的构造及其性能分析　出处：《西安邮电大学》2015年硕士论文　论文类型：学位论文

【摘要】：如今信息化时代步伐加快,信息安全在军事通信中的作用越来越重要,人们对传输信息的要求越来越高,鉴于扩频通信具有良好的保密性、抗截获和抗干扰能力,以及码分多址等优点,目前扩频通信在民用通信、军事通信中的应用越来越多。直接序列扩频通信系统成为了一种技术最成熟、应用最广泛的扩频通信方式,在直扩通信系统中,通信系统符号间干扰的大小和多址干扰的强度很大程度上取决于扩频码序列特性的优劣,导致系统性能受到直接影响。因此,对扩频序列性质的深入研究、寻找具有优良性能扩频序列的设计方案是直扩通信系统的核心课题,同时成为本论文的主要研究内容。本论文首先介绍了扩频通信理论的发展、扩频通信的基础知识及其相关理论。其次,从不同的角度分类、讨论了扩频码序列,着重研究了三元组扩频序列、混沌理论、自编码扩频通信系统及其改进序列的设计方法,本文取得的主要研究成果如下：第一,首先简要介绍扩频技术,然后以序列生成器的不同作为区分扩频序列的主要手段,研究了不同种类的扩频序列的优缺点,总结出扩频码应具备的优良特性,以便为新扩频序列的提出做准备。扩频序列应具备良好的自相关性、互相关性、平衡性、游程性、复杂性和混沌性等基本的数学统计特性,最后本文给予了简明扼要的分析。第二,简要介绍了由用户的输入信息、选择的广义信息作为初值和背景、空间轨迹变换作为算法的三元组随机数序列,对该体制新颖的序列进行经典正交变换和均匀同态变换,获得互相关性好的正交三元组扩频码和随机性高的同态三元组扩频码。然后性能测试并验证分析正交三元组扩频序列和同态三元组扩频码的相关性、平衡度和Lyapunov指数,以及在直扩通信系统中的误码率,结果表明：三元组扩频码的性能优良,并且误码率较低,尤其是正交三元组扩频序列的误码率最低,可以替代PN序列作为扩频通信系统的扩频码。第三,简要介绍从信源信息序列中获取扩频码的自编码扩频通信系统,研究了混沌映射、二维离散超混沌映射与自编码扩频序列融合的方式,以及相空间轨迹重构法改进自编码扩频序列的方式,基于AR自编码扩频序列获取了混沌-AR自编码扩频序列、超混沌-AR自编码扩频序列和相空间-AR自编码扩频序列,通过软件仿真同时分析检验扩频序列的性能和传输误码率。第四,利用多用户通信系统模型,在高斯白噪声信道和瑞利信道中仿真论文提出的扩频码和传统扩频序列在不同信噪比下的误码率。同时验证了不同扩频增益下各种扩频码的误码率差别很大,随着扩频增益的提高,通信系统的误码率明显降低。本文提出的扩频序列较传统扩频码有较强的复杂度和随机性,可以提高通信系统的安全性以及传输信息的抗截获性。若以传输信息的误码率作为评价扩频序列的主要指标,则相空间AR自编码扩频序列是本文扩频码中最优的,然后分别是超混沌-AR自编码扩频序列、混沌-AR自编码扩频序列和正交三元组扩频码,相对较差的是同态三元组扩频码。
[Abstract]:Now the information age to accelerate the pace of information security becomes more and more important in military communication, people transmit information on the increasingly high demand, in view of the spread spectrum communication has a good security, anti interception and anti-jamming ability, and the advantages of CDMA spread spectrum communication in civil communication, at present, more and more applications in the military communication. Direct sequence spread spectrum communication system has become a kind of spread spectrum communication technology is the most mature, the most widely used, in DSSS communication system, communication system, intersymbol interference and multiple access interference intensity size depends largely on the sequence characteristics of the pros and cons, make the performance of the system directly affected. Therefore, further study on the properties of the spreading sequence, find the design scheme with good performance of spread spectrum sequence is the core issue of DSSS communication system, and become the main research of this paper. Volume. This paper first introduces the development of the theory of spread spectrum communication, the theory of spread spectrum communication and related theories. Secondly, the classification from different angles, discusses the spreading sequence, focuses on the three tuple sequence, chaos theory, self encoding in spread spectrum communication system and its design method to improve the sequence, the main achievement of the thesis are as follows: first, briefly introduces the spread spectrum technology, the main means and in different as the sequence generator distinguish the spreading sequence, the advantages and disadvantages of different kinds of spread spectrum sequence, summed up the excellent characteristics of the spreading codes should have, in order to put forward a new spreading sequence ready. Spread spectrum sequence should have good correlation, cross correlation, balance, run length, mathematical statistics and other basic complexity and chaos, finally this paper gives a concise and to the point analysis. Second, brief introduction From the user's input information, select the generalized information as the initial condition and background, the space trajectory transform as the three tuple sequence of random number algorithm, classical orthogonal transform and homomorphic transform of uniform sequence of the new system, obtain the cross-correlation orthogonality of the three tuple spreading codes and random spreading codes three tuple high homomorphism the performance test and verification. Then correlation analysis of orthogonal spreading sequences and three tuple homomorphism of three tuple codes, balance degree and Lyapunov index, as well as in DSSS communication system BER, the results show that the performance of the three tuple codes are excellent, and the bit error rate is low, especially the error of three tuple orthogonal sequences the lowest rate, can replace the PN sequences as spreading codes in spread spectrum communication system. Since Third, encoding in spread spectrum communication system are briefly introduced from the source information in the sequence acquisition of spread spectrum codes, were investigated Chaos mapping, two-dimensional discrete hyperchaotic mapping and fusion self encoding sequence, and the phase space trajectory reconstruction method improves the self encoding sequence, obtained by AR chaotic spread spectrum sequence encoding -AR from self encoding sequences based on chaotic spread spectrum sequence and -AR encoding phase space -AR encoding sequence by software the simulation and analysis of performance and BER Test sequence. Fourth, multi user communication system model, the Gauss white noise channel and Rayleigh channel simulation of the spread spectrum code and traditional spread spectrum sequence in BER under different SNR. At the same time to verify the different spreading gain error of various PN code rate very different, with spread spectrum gain increases, the error rate of communication system is reduced obviously. The spread spectrum sequence is proposed in this paper compared with the traditional spreading codes have complexity and randomicity, Can improve the anti interception of communication system security and transmission of information. If the information transmission error rate as the main index to evaluate the spreading sequence, then phase space AR encoding spread spectrum sequence is the spreading codes in the best, then is -AR chaotic spread spectrum sequence self encoding, -AR encoding and chaotic spread spectrum sequence three tuple orthogonal spreading codes, the relatively poor is homomorphic three tuple spreading codes.

【学位授予单位】：西安邮电大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN914.42

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