一种由移位数列生成GMW序列和级联GMW序列的新算法

该文提出了一种新的根据移位数列生成GMW序列和级联GMW序列的构造方法,该方法简化了传统的GMW序列和级联GMW序列的构造方法,大大提高了生成效率,且验证了其可行性。     

级联GMW序列的三项式特性

利用有限域上迹函数的性质,讨论了一类非线性扩频序列:级联GMW序列的三项式特性,即移位相加性。给出了此类序列的三项式时,并对级联GMW序列的性质作了一些讨论。     

二元GMW序列Niho采样下的互相关性分析

GMW序列是一种线性复杂度很高的非线性序列,在直接序列扩频系统中有着很好的应用前景.通过证明级联二元GMW序列与其采样序列的互相关性在特定条下和构造级联GMW序列的幂无关,将二元GMW序列与其采样序列的互相关性与m序列联系起来.通过现有二元m序列在Niho采样下的互相关性研究结论,分析证明了级联二元GMW序列在Niho采样下的互相关性具有四值、五值、六值特性.     

一类新的性能优异的伪随机序列——GMW相控序列

基于交错方法构造出了一类新的伪随机序列,称为GMW相控序列.给出了GMW相控序列的生成算法,证明了GMW相控序列均满足平衡性,具有优良的相关特性和极大的线性复杂度,可适用于CDMA扩频通信和保密通信系统中.     

相控序列的改进——采用级连GMW序列 构造相控序列

本文介绍了一种新型伪随机序列－相控序列,相控序列具有线性复杂度很大,相关性好,序列平衡的优点.本文提出了对相控序列的改进,使用级连GMW序列代替原始定义中生成相控序列所需的GMW序列,并证明了这种改进的可行性.改进后的相控序列的线性复杂度进一步增大,族数增多但相关性和平衡性不变.     

一种快速构造具有最大线性复杂度GMW序列的方法

本文研究了计算GMW序列线性复杂度的算法,在此基础上对其进行了简化,得到了一种方法,来快速构造给定周期长度的GMW序列,使其具有最大线性复杂度.利用此方法工程人员可以无须掌握太多数学知识而很快捷的得到理想的GMW序列并将之应用到扩频多址通信系统中,从而使整个系统具有最佳性能.     

Galois环上的一类GMW序列及其线性复杂度

将有限域上GMW序列的概念推广到了一般的Galois环上.利用环上的置换,定义了一类新的一般Galois环上的GMW序列,并对其线性复杂度进行了估计.结果表明,这类GMW序列具有非常大的线性复杂度.     

非线性扩频序列的三项式特性

讨论了三类非线性扩频序列(GMW序列、No序列和Kasami序列)的三项式特性，利用这三类序列的迹表示，证明了GMW序列、No序列和Kasami序列均具有正则三项式对。     

GMW序列和WG序列及WG序列间的互相关特性

对于奇数n,研究了Gordon-Mills-Welch（GMW）序列与Welch-Gong（WG）序列（及其某一采样序列）间的互相关函数以及WG序列间的互相关函数。研究表明：GMW序列与WG序列（及其某一采样序列）间的互相关函数以及WG序列间的互相关函数最终均与m-序列与其采样序列间的互相关函数相关;并且在一定条件下,WG序列间的互相关函数可为3-值或5-值的。另外,给出了GMW序列与WG序列间互相关函数的最大峰值。     

基于GMW序列构造最佳跳频序列族

本文提出基于ＧＭＷ序列构造跳频序列族的两种方法，证明构造的跳频序列族具有最佳的汉明相关性能。     

Cross-correlation of p-ary GMW sequences

The cross-correlation function of p-ary (p prime) GMW sequences is investigated. The well-known m-sequences are incorporated in these sequences. GMW sequences also have the two-level autocorrelation function, but their linear span may be much larger than those of m sequences. The calculation of the cross-correlation function of GMW sequences is reduced to the cross-correlation of the m-sequences because many results on this kind of sequence are known. In the literature, only the cross-correlation function of an m sequence with a GMW sequence has been known up to now     

Cascaded GMW sequences

Pseudorandom binary sequences with high linear complexity and low correlation function values are sought in many applications of modern communication systems. A new family of pseudorandom binary sequences, cascaded GMW sequences, is constructed. These sequences are shown to share many desirable correlation properties with the GMW sequences of B. Gordon, W.A. Mills, and L.R. Welch (1962)-for example, high-shifted autocorrelation values and, in many cases, three-valued cross-correlation values with m-sequences. It is shown, moreover, that in many cases the linear complexities of cascaded GMW sequences are far greater than those of GMW sequences     

GMW sequences (Corresp.)

The difference set design of Gordon, Mills, and Welch (GMW) is adapted for use as a pseudorandom number generator. Statistical properties of the generated binary sequences, including periodic correlation, linear span, andk-tuple statistics, are derived. One mechanization of a GMW sequence generator is suggested, and the number of sequences that can be generated with a fixed number of shift-register stages and read-only memory (ROM) size is evaluated.     

A SYNCHRONIZATION ALGORITHM FOR HF （HIGH FREQUENCY） BROADBAND OFDM SYSTEM

In this letter, a kind of associated synchronization algorithm which is suitable for HF （High Frequency） broadband OFDM （Orthogonal Frequency Division Multiplexing） system is presented based on describing and constructing the GMW （Gorden, Mills and Welch） sequence. The algorithm is based on the Schmidl and Minn＇s symbol timing principle, the constructed GMW sequence is transmitted and disposed, and the synchronization is adjudicated using the correlation of GMW sequence. The simulation result indicates that this algorithm has high performance synchronization ability under the low SNR （Signal to Noise Ratio） at two different kinds of channel models.     

DS-CDMA系统正交码调制的抗多址干扰性能及其改进

本文推导非同步 Ｃ Ｄ Ｍ Ａ 系统多址干扰表达式,计算正交码调制码组相关性对多址干扰的影响。提出一种改进型 Ｗ ａｌｓｈ＋ Ｇ Ｍ Ｗ 正交码组,分析比较 Ｗ ａｌｓｈ 正交码组和 Ｗ ａｌｓｈ＋ Ｇ Ｍ Ｗ 正交码组应用于非同步 Ｃ Ｄ Ｍ Ａ 系统的性能。计算机模拟结果表明应用改进型正交码组时系统性能获得改善。