共查询到18条相似文献,搜索用时 203 毫秒
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为了弥补四相正交序列周期短的缺陷,将最佳四相正交序列应用于零相关区(ZCZ,Zero Correlation Zone)序列中,提出一种用交织法构建四相ZCZ序列的方法。首先选择合适的移位序列,经交织变换生成具有更长周期的ZCZ序列,再用正交矩阵将该序列进行扩展而得到新的序列集,实现了最佳四相正交序列和正交矩阵的结合。该方法构造的序列具有更大的周期和较大的容量,从而可以更好地在实际工程中加以利用。 相似文献
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在准同步CDMA系统中,使用零相关区(ZCZ)序列能够避免共信道冲突和多址干扰。通过应用序列偶理论,基于交织技术和一类最优ZCZ序列集中的移位序列,成功构造出了具有良好自相关和互相关性能的ZCZ序列偶集,不但可以生成不同的零相关区,而且使得序列偶集中的所有序列都循环移位不等价。仿真结果表明,它的性能优良,适于作准同步CDMA系统的扩频序列。 相似文献
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Wang Jinsong Qi Wenfeng 《电子科学学刊(英文版)》2007,24(3):301-304
In an Approximately Synchronized Code Division Multiple Access (AS-CDMA) communication system, a family with large number of Zero Correlation Zone (ZCZ) sequences is desired, which can satisfy the rapid increase of users. This paper presents a method to generate a (2L,2M, ZCZ')-ZCZ sequence family from an original (L,M,ZCZ)-ZCZ sequence family, where ZCZ' = ZCZ if ZCZ is even and ZCZ' =ZCZ - 1 if ZCZ is odd. This method can also recursively act on a ZCZ sequence family to construct a series of ZCZ sequence families with large sequence number and zero correlation zone length identical to or one less than that of original ZCZ sequences. 相似文献
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Bent序列和Gold-like序列的构造 总被引:3,自引:0,他引:3
该文研究Bent序列和Gold-like序列, 设计了3类快速生成的Bent序列, 此外, 基于Klapper(1993)对几何序列相关性的分析, 递归地构造了一类Gold-like序列, 所得的Gold-like序列涵括了Khoo, Gong和Stinson(2002)递归生成的Gold-like序列。 根据Olsen, Scholtz和Welch(1982)给出的Bent序列簇的构造方法, 该文得到的Bent序列可以迅速地构造Bent序列簇。此外, 该文得到的Gold-like序列可以用来设计大周期的扩频序列簇。 相似文献
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Large families of quaternary sequences with low correlation 总被引:1,自引:0,他引:1
Kumar P.V. Helleseth T. Calderbank A.R. Hammons A.R. Jr. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》1996,42(2):579-592
A family of quaternary (Z4-alphabet) sequences of length L=2r-1, size M⩾L2+3L+2, and maximum nontrivial correlation parameter Cmax⩽2√(L+1)+1 is presented. The sequence family always contains the four-phase family 𝒜. When r is odd, it includes the family of binary Gold sequences. The sequence family is easily generated using two shift registers, one binary, the other quaternary. The distribution of correlation values is provided. The construction can be extended to produce a chain of sequence families, with each family in the chain containing the preceding family. This gives the design flexibility with respect to the number of intermittent users that can be supported, in a code-division multiple-access cellular radio system. When r is odd, the sequence families in the chain correspond to shortened Z4-linear versions of the Delsarte-Goethals codes 相似文献
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Popovic B.M. Suehiro N. Fan P.Z. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2002,48(4):956-959
A general construction for orthogonal sets of quadriphase sequences based on the sequence family A discovered by Sole (1989), Boztas, Hammons, and Kumar (1992) is presented. The sequence family A is equivalent to the S(0) family that belongs to a chain of sequence families S(i),i=0,1,2,..., m with each family in the chain containing the preceding family. Therefore, a number of orthogonal subsets can be generated for an arbitrary family S(m). The algorithm for an efficient implementation of the bank of correlators corresponding to any orthogonal subset of family S(m) is derived as well 相似文献
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The construction of zero correlation zone (ZCZ) sequence set was researched based on perfect sequences and orthogonal sequence set.With the method of constructing on finite field,the optimal zero correlation zone sequence sets were constructed,by changing the set O and R,multiple shift distinct ZCZ sequence sets could be obtained and the number of sets could be expended.Through the constructions,the length of ZCZ can be chosen flexibly to meet the requirements of different systems for channel delay under the condition of or ,where p is a prime. 相似文献