【作者】 梁清梅；

【导师】 许成谦；

【作者基本信息】 燕山大学 ， 电路与系统， 2006， 硕士

【摘要】 在准同步CDMA通信系统中,对所采用扩频地址码的要求是在同步误差范围内(零时延附近)具有理想的相关特性,零相关区(ZCZ)序列就是能够满足这样要求的序列。本文在总结和比较了目前已有的ZCZ序列的设计方法后,本着改变二元ZCZ序列存在不足现状的目的,应用序列偶理论,结合零相关区(ZCZ)序列的特性,定义了一种具有零相关区的多值自相关序列偶——ZCZ序列偶,在此基础上对ZCZ序列偶集合进行了一系列的理论研究。主要工作如下:(1)介绍了序列偶的基本概念和序列偶自相关函数的性质,以及序列偶在信号处理和通信系统中的应用。(2)给出了ZCZ序列偶的定义,并推广得到了ZCZ互补序列偶的定义。讨论了ZCZ序列偶存在的必要条件、峰值特性、构造方法以及自相关函数的变换性质。(3)定义了ZCZ序列偶集合的概念,给出并证明了ZCZ序列偶集合的几种变换性质;推导了ZCZ序列偶集合的理论限,并结合零相关区序列的研究现状对理论限作了讨论;提出了两种构造ZCZ序列偶集合的方法,这两种方法能够构造出渐近甚至是达到理论上限的集合。最后通过与一般ZCZ序列的比较对ZCZ序列偶集合的性能作了分析。(4)总结了ZCZ序列的设计方法,提出构造一般二元ZCZ序列的新方法——级联法,通过与已有构造法的比较,对级联构造法做出了综合评价。最后介绍了ZCZ序列在实际中的两点应用。结果表明,ZCZ序列偶集合是一种特殊的二元零相关区序列,它的性能优良,适于作准同步CDMA系统的扩频序列。更多还原

【Abstract】 In the quasi-synchronous CDMA system, the request to adopt the spreadingsequence is that the sequence should have perfect correlation properties in thesynchronous error (near the zero time delay), the zero-correlation zone (ZCZ)sequence is just fit for the need. After summarizing and comparing the knowndesign methods of ZCZ sequence, to alter the deficiency of the binary ZCZsequence, applying the sequence pair theory and combining the properties ofZCZ sequence, the paper defines a multi-value self-correlation sequence pair(ZCZ sequence pair) which has zero correlation zone. Based on these matters,the paper makes a series of theory study for the ZCZ sequence pair set. Themain work is just as following:(1)The basic concepts of sequence pair, the correlation properties of thesequence pair and the applications of the sequence pair in the signal process andcommunication system are introduced.(2)The paper presents the definition of the ZCZ sequence pair, and extendsto the definition of the ZCZ complementary sequence pair. The paper alsodiscusses the necessary condition of the being of ZCZ sequence pair, peak valuecharacteristic, construction methods and the transform properties of theself-correlation function. (3)The paper defines the concept of the ZCZ sequence set, presents andproves the several transform properties of the ZCZ sequence set. The paperdeduces the theory bound of the ZCZ sequence set, and also combining thestudy actuality of zero correlation sequence makes some discussion about thebound. The paper presents two construction methods of the ZCZ sequence pair.The ZCZ sequence sets which are constructed by the two methods can approachor get the upper bound. Finally, through comparing with the common ZCZsequence the paper makes some analysis about the performance of the ZCZsequence pair set.(4)The paper summarizes the design methods of ZCZ sequence, presents anew means to structure binary ZCZ sequence: that is step link method. Throughcomparing with the known structure methods, the text makes integratedevaluation to the step link method. At last, the paper introduces two applicationsof the ZCZ sequence in the practice system.The result indicates that the ZCZ sequence pair set is a peculiar binary zerocorrelation sequence. At the same time, its performance is perfect, it is befittingto use as the spread spectrum sequence in the quasi-synchronous CDMA system.更多还原