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Chebyshev映射混沌扩频序列的奇/偶相关特性分析 被引量:1
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作者 刘如军 涂虬 《湛江师范学院学报》 2001年第6期10-13,共4页
分析Chebyshev映射混沌扩频序列的奇 /偶相关特性 ,并通过计算机仿真 ,说明Chebyshev映射混沌扩频序列具有理想的奇
关键词 通信系统 混沌序列 CHEBYSHEV映射 混沌扩频序列 奇相关 相关 计算机仿真 直扩码分多地址系统 序列长度
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Logistic映射混沌扩频序列的奇/偶相关特性分析 被引量:4
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作者 蔡国权 宋国文 +1 位作者 于大鹏 李红波 《电子学报》 EI CAS CSCD 北大核心 1999年第S1期128-130,共3页
本文简要分析了Logistic映射混沌扩频序列的奇 /偶相关特性以及序列的有限长度效应对奇 /偶相关特性的影响 ;提出了一种EOELogistic映射混沌扩频序列的构造方法 .理论分析表明 ,EOELogistic映射有限长度扩频序列的奇 /偶相关特性较原序... 本文简要分析了Logistic映射混沌扩频序列的奇 /偶相关特性以及序列的有限长度效应对奇 /偶相关特性的影响 ;提出了一种EOELogistic映射混沌扩频序列的构造方法 .理论分析表明 ,EOELogistic映射有限长度扩频序列的奇 /偶相关特性较原序列有所改善 . 展开更多
关键词 LOGISTIC映射 混沌扩频序列 /偶相关函数 多址干扰 DS/CDMA
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GPS L1C信号Weil码相关性能分析 被引量:13
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作者 何成龙 王垚 《无线电通信技术》 2013年第1期32-35,共4页
伪码是码分多址信号的基本组成,寻找具有良好相关性能的伪码是基于码分多址的无线通信和无线电导航等信号设计中的重要环节。Weil码是一种基于勒让德序列移位相加形成的伪随机码,具有良好的相关性能,且具有相对灵活的可选序列长度,将在... 伪码是码分多址信号的基本组成,寻找具有良好相关性能的伪码是基于码分多址的无线通信和无线电导航等信号设计中的重要环节。Weil码是一种基于勒让德序列移位相加形成的伪随机码,具有良好的相关性能,且具有相对灵活的可选序列长度,将在GPS的L1C信号中得到应用。在提出伪码选择方法的基础上,对Weil码的产生方式进行了介绍,并对几种典型的伪码的理论相关性能和序列长度特点进行对比分析,对L1C信号采用的126个Weil码的奇相关和偶相关性能进行仿真,结果表明在10 230的序列长度下Weil码具有良好的相关性能。 展开更多
关键词 勒让德序列 Weil码 奇相关 相关.
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用于CDMA的四相混沌扩频序列 被引量:16
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作者 凌聪 孙松庚 《通信学报》 EI CSCD 北大核心 1998年第3期40-44,共5页
本文由混沌映射产生用于直扩码分多址(DS/CDMA)系统的四相扩频序列,证明了周期为N的此类扩频序列的四种广义奇相关均服从均方值为N的瑞利分布。混沌四相序列的相关峰值较混沌二相序列有显著的下降,多址性能与传统四相扩频... 本文由混沌映射产生用于直扩码分多址(DS/CDMA)系统的四相扩频序列,证明了周期为N的此类扩频序列的四种广义奇相关均服从均方值为N的瑞利分布。混沌四相序列的相关峰值较混沌二相序列有显著的下降,多址性能与传统四相扩频序列相同。 展开更多
关键词 混沌 四相扩频序列 广义奇相关 扩频通信系统
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用于混沌扩频保密通信的不等长四相扩频序列
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作者 韦岗 田传俊 谢胜利 《通信学报》 EI CSCD 北大核心 2001年第5期80-85,共6页
本文重点研究不等长四相混沌扩频序列的广义奇互相关性质。理论分析和仿真实验表明 ,不等长与等长的四相混沌扩频序列在许多方面具有相似的性质 ,所获结果为不等长四相混沌扩频序列在保密通信等方面的应用提供了理论基础。
关键词 混沌扩频 保密通信 不等长四相扩频序列 广义奇相关
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一种Z_4线性码四相扩频序列的分析
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作者 蔡国权 高世海 宋国文 《信息工程大学学报》 2001年第1期39-42,共4页
本文首先分析了Z4 序列的平衡特性 ;然后详细讨论了Z4码四相扩频序列的广义奇相关的分布 ;并就相关峰值和相关均方值等相关特性 ,通过计算机仿真 ,将Z4码四相扩频序列与其它四相扩频序列进行比较。结果表明 ,Z4码四相扩频序列具有优良... 本文首先分析了Z4 序列的平衡特性 ;然后详细讨论了Z4码四相扩频序列的广义奇相关的分布 ;并就相关峰值和相关均方值等相关特性 ,通过计算机仿真 ,将Z4码四相扩频序列与其它四相扩频序列进行比较。结果表明 ,Z4码四相扩频序列具有优良的相关特性 ,可作为DS/CDMA四相扩频序列的侯选。 展开更多
关键词 Z4码四相矿频序列 广义奇相关 平衡特性 多址干扰 DS/COMA 扩频技术 相关特性
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北斗三号等长Weil码和Gold码性能分析与比较 被引量:3
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作者 张瀚青 何在民 +1 位作者 叶旅洋 马红皎 《计算机仿真》 北大核心 2019年第8期71-76,共6页
测距码在卫星导航系统中占据重要地位,北斗三号B1C信号和B2a信号测距码分别采用Weil码截短和Gold码增补的方式生成。探讨了北斗三号两种测距码的生成原理,基于FPGA实现了两种测距码数据分量主码的生成,并给出码生成仿真结果。基于传统... 测距码在卫星导航系统中占据重要地位,北斗三号B1C信号和B2a信号测距码分别采用Weil码截短和Gold码增补的方式生成。探讨了北斗三号两种测距码的生成原理,基于FPGA实现了两种测距码数据分量主码的生成,并给出码生成仿真结果。基于传统相关定义,根据覆盖区域大小进行两种测距码相关性能的定性分析;引入奇/偶相关判据,利用最大相关旁瓣能量对两种测距码作相关性能的定量分析。基于定性与定量分析进行两种测距码的性能比较,结果表明,在码长同为10230的情况下,Weil码具有比Gold码更好的相关性能,更有利于卫星信号的捕获与跟踪。 展开更多
关键词 北斗三号 勒让德序列 测距码 /偶相关
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多相位编码载波二相扩频CDMA系统模型分析
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作者 钟杏梅 蔡国权 牛忠霞 《信息工程大学学报》 2000年第1期44-46,共3页
本文讨论了以直接序列扩频为基础的多相位编码载波二相扩频CDMA系统模型 ,就扩频序列的相关性与多址干扰的关系进行了定量分析 ,分别给出了多址干扰与扩频序列的奇、偶互相关函数的数学关系式。本文还对文献 [1 ]中的错误进行了分析。
关键词 扩频序列 、偶相关函数 多址干扰 同信道干扰 CDMA
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A Fault Detection and Isolation Scheme Based on Parity Space Method for Discrete Time-delay System 被引量:1
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作者 王红雨 田作华 +1 位作者 施颂椒 翁正新 《Journal of Donghua University(English Edition)》 EI CAS 2008年第3期304-307,共4页
A Fault detection and isolation(FDI)scheme for discrete time-delay system is proposed in this paper,which can not only detect but also isolate the faults.A time delay operator is introduced to resolve the problem bro... A Fault detection and isolation(FDI)scheme for discrete time-delay system is proposed in this paper,which can not only detect but also isolate the faults.A time delay operator is introduced to resolve the problem brought by the time-delay system.The design and computation for the FDI system is carried by computer math tool Maple,which can easily deal with the symbolic computation.Residuals in the form of parity space can be deduced from the recursion of the system equations.Further more,a generalized residual set is created using the freedom of the parity space redundancy.Thus,both fault detection and fault isolation have been accomplished.The proposed method has been verified by a numerical example. 展开更多
关键词 fault detection and isolation parity space time-delay system
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Morphotaxonomy and seasonal distribution of planktonic and benthic Prorocentrales in Karachi waters,Pakistan Northern Arabian Sea
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作者 Sonia MUNIR Zaib-un-nisa BURHAN +2 位作者 Tahira NAZ P.J.A.SIDDIQUI Steve L.MORTON 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2013年第2期267-281,共15页
Morphotaxonomy and seasonal abundance of dinoflagellates of the genera Prorocentrum and Mesoporos (Prorocentrales) were studied from nutrient-rich waters, Karachi Harbor and the mouth of the Manora Channel, Pakistan... Morphotaxonomy and seasonal abundance of dinoflagellates of the genera Prorocentrum and Mesoporos (Prorocentrales) were studied from nutrient-rich waters, Karachi Harbor and the mouth of the Manora Channel, Pakistan during May 2002-July 2003. Using both light and scanning electron microscopy, 13 species of Prorocentrales were identified according to cell shape, size, ornamentation of thecal plates, and architecture of apical platelets, apical pore area, marginal pores, and intercalary bands. P. sigmoides, P. arcuatum, P. scutellum, P. donghaiense, P. balticum, P. minimum, P. emarginatum, P. lima, P. faustiae, and Mesoporos perforatus constitute new records for sindh coast of Pakistan. The most abundant species were P. minimum/P, balticum (4.5x103 cells/L), P. micans (1.1~103 cells/L), P. gracile/P, sigmoides (2.5 x 102 cells/L) and P. donghaiense (6.6 x 103 cells/L) at temperatures of 29-31 ~C and salinities of 35-40. Maximum abundance was observed in winter and lower abundance in summer. There was no significant change in the distribution of species between stations except for the benthic species which occurred close to Karachi Harbor waters. Significant positive correlations were observed between Prorocentrum spp. and temperature (R2=0.27) and negative correlations with salinity (R2=-0.32) except for P. minimum and P. emarginatum which has negative correlation with temperature (R2=-0.24) and positive with salinity (R2=0.08, 0.19). The finding of potential okadaic-acid producing species of benthic Prorocentrum call for monitoring for possible human health problems in this region. 展开更多
关键词 ecology morphology planktonic/benthic Prorocentrales harmful algae scanning electronaaicroscopy northern Arabian Sea
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THE CORRELATION BETWEEN THE PACIFIC SEA SURFACE TEMPERATURE(SST) and PRECIPITATION OVER NW CHINA 被引量:1
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作者 王澄海 王式功 +1 位作者 杨德保 董安祥 《Journal of Tropical Meteorology》 SCIE 2003年第1期64-73,共10页
With the singular value decomposition (SVD), correlation analysis has been conducted between the Pacific Ocean sea surface temperature (SST) and northwestern China precipitation over March May (MAM). The result shows ... With the singular value decomposition (SVD), correlation analysis has been conducted between the Pacific Ocean sea surface temperature (SST) and northwestern China precipitation over March May (MAM). The result shows that there is good relationship between the North Pacific and spring precipitation in northwestern China. When the SST is of the peak El Ni駉 phase, precipitation is less over this part of the country except for the Qinghai-Tibetan Plateau; when the SST for the months DJF is of the mature El Ni駉 phase, precipitation is more over the region in the subsequent March May; when the North Pacific SST for DJF is of the La Ni馻 pattern, precipitation is less over the plateau in the subsequent March May. For the Pacific SST, the westerly drift, kuroshio current, Californian current and north equatorial current are all significantly correlating with the March May precipitation in northwestern China. Specifically, the SST in DJF over the kuroshio current region is out of phase with the precipitation in northern Xinjiang, i.e. when the former is low, the latter is more. In northwestern China, regions in which March May precipitation response to the variation of SST in the Pacific Ocean are northern Xinjiang, the Qinghai-Tibetan Plateau and areas off its northeastern part, the desert basin and western part of the Corridor of the Great Bend of Yellow River valley (Corridor). 展开更多
关键词 precipitation of Northwest China Pacific sea surface temperature (SST) singular value decomposition (SVD)
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ODD-PERIODIC AND PERIODIC COMPLEMENTARY BINARY SEQUENCES
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作者 WenHong HuFei JinFan 《Journal of Electronics(China)》 2005年第1期42-46,共5页
Two or more sequences are called an Odd-Periodic Complementary binary sequences Set (OPCS) if the sum of their respective odd-periodic autocorrelation function is a delta function. In this paper, the definition of OPC... Two or more sequences are called an Odd-Periodic Complementary binary sequences Set (OPCS) if the sum of their respective odd-periodic autocorrelation function is a delta function. In this paper, the definition of OPCS is given and the construction method of OPCS is discussed. The relation of the OPCS with the Periodic Complementary binary sequences Set (PCS) is pointed out, and some new PCSs are obtained based on such relation. 展开更多
关键词 Odd-periodic Complementary sequences Correlation function
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异步多相DS/CDMA系统模型分析 被引量:4
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作者 蔡国权 宋国文 于大鹏 《通信技术》 1999年第2期34-38,共5页
文章在文献[1]的基础上讨论了以直接序列扩频为基础的正交多相位编码载波多相扩频CDMA系统模型,就扩频序列的相关性与多址干扰的关系进行了定量分析,修正了扩频序列的非周期相关函数的定义,给出了多址干扰与扩频序列的广义奇... 文章在文献[1]的基础上讨论了以直接序列扩频为基础的正交多相位编码载波多相扩频CDMA系统模型,就扩频序列的相关性与多址干扰的关系进行了定量分析,修正了扩频序列的非周期相关函数的定义,给出了多址干扰与扩频序列的广义奇相关函数的数学关系式。文章还对文献[1]中的错误进行了分析。 展开更多
关键词 扩频序列 广义奇相关 多址通信系统 CDMA
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基于混沌和CNN交错反馈产生扩频序列的性能分析 被引量:1
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作者 叶群 王玲 +1 位作者 肖要强 倪问尹 《通信技术》 2008年第12期72-74,共3页
提出了一种基于细胞神经网络和混沌交错反馈产生扩频序列的设计方法,用计算机仿真对该混沌扩频序列的平衡特性、游程特性、位移特性、相关特性和线性复杂度等伪随机特性进行了系统的分析,并分析了该序列的奇/偶相关特性。结果表明,该混... 提出了一种基于细胞神经网络和混沌交错反馈产生扩频序列的设计方法,用计算机仿真对该混沌扩频序列的平衡特性、游程特性、位移特性、相关特性和线性复杂度等伪随机特性进行了系统的分析,并分析了该序列的奇/偶相关特性。结果表明,该混沌扩频序列具有理想的伪随机特性,可以作为扩频通信中的扩频码,同时系统的交错加强了通信的保密性。 展开更多
关键词 细胞神经网络 混沌 /偶相关特性 扩频
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Some progress in spectral methods Dedicated to Professor Shi Zhong-Ci on the Occasion of his 80th Birthday 被引量:3
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作者 GUO BenYu 《Science China Mathematics》 SCIE 2013年第12期2411-2438,共28页
In this paper, we review some results on the spectral methods. We first consider the Jacobi spectral method and the generalized Jacobi spectral method for various problems, including degenerated and singular different... In this paper, we review some results on the spectral methods. We first consider the Jacobi spectral method and the generalized Jacobi spectral method for various problems, including degenerated and singular differential equations. Then we present the generalized Jacobi quasi-orthogonal approximation and its applica- tions to the spectral element methods for high order problems with mixed inhomogeneous boundary conditions. We also discuss the related spectral methods for non-rectangular domains and the irrational spectral methods for unbounded domains. Next, we consider the Hermite spectral method and the generalized Hermite spec- tral method with their applications. Finally, we consider the Laguerre spectral method and the generalized Laguerre spectral method for many problems defined on unbounded domains. We also present the generalized Laguerre quasi-orthogonal approximation and its applications to certain problems of non-standard type and exterior problems. 展开更多
关键词 JACOBI Hermite and Laguerre spectral approximations Jacobi and Laguerre quasi-orthogonalapproximations spectral and spectral element methods degenerated and singular problems problems on non-rectangular and unbounded domains problems of non-standard type exterior problems
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Properties of color-flavor locked strange quark matter and strange stars in a new quark mass scaling 被引量:3
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作者 CHANG Qian CHEN ShiWu +1 位作者 PENG GuangXiong XU JianFeng 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2013年第9期1730-1734,共5页
Considering the effect of one-gluon-exchange interaction between quarks,the color-flavor locked strange quark matter and strange stars are investigated in a new quark mass density-dependent model.It is found that the ... Considering the effect of one-gluon-exchange interaction between quarks,the color-flavor locked strange quark matter and strange stars are investigated in a new quark mass density-dependent model.It is found that the color-flavor locked strange quark matter can be more stable if the one-gluon-exchange effect is included.The lower density behavior of the sound velocity in this model is different from the previous results.Moreover,the new equation of state leads to a heavier acceptable maximum mass,supporting the recent observation of a compact star mass as large as about 2 times the solar mass. 展开更多
关键词 color-flavor locked strange quark matter one-gluon-exchange effect
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Investigation of the two-quasiparticle bands in the doubly-odd nucleus ^(166)Ta using a particle-number conserving cranked shell model
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作者 ZhenHua Zhang 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2016年第7期33-39,共7页
The high-spin rotational properties of two-quasiparticle bands in the doubly-odd 166Ta are analyzed using the cranked shell model with pairing correlations treated by a particle-number conserving method, in which the ... The high-spin rotational properties of two-quasiparticle bands in the doubly-odd 166Ta are analyzed using the cranked shell model with pairing correlations treated by a particle-number conserving method, in which the blocking effects are taken into account exactly. The experimental moments of inertia and alignments and their variations with the rotational frequency hw are reproduced very well by the particle-number conserving calculations, which provides a reliable support to the configuration assignments in previous works for these bands. The backbendings in these two-quasiparticle bands are analyzed by the calculated occupation probabilities and the contributions of each orbital to the total angular momentum alignments. The moments of inertia and alignments for the Gallagher-Moszkowski partners of these observed two-quasiparticle rotational bands are also predicted. 展开更多
关键词 particle-number conserving method pairing correlations moment of inertia
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New Metrics from a Fractional Gravitational Field
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作者 Rami Ahmad El-Nabulsi 《Communications in Theoretical Physics》 SCIE CAS CSCD 2017年第9期309-312,共4页
Agop et al. proved in Commun. Theor. Phys. (2008) that, a Reissner-Nordstrom type metric is obtained, if gauge gravitational field in a fractal spacetime is constructed by means of concepts of scale relativity. We p... Agop et al. proved in Commun. Theor. Phys. (2008) that, a Reissner-Nordstrom type metric is obtained, if gauge gravitational field in a fractal spacetime is constructed by means of concepts of scale relativity. We prove in this short communication that similar result is obtained if gravity in D-spacetime dimensions is fractionalized by means of the Glaeske-Kilbaz Saigo fractional. Besides, non-singular gravitational fields are obtained without using extra-dimensions. We present few examples to show that these gravitational fields hold a number of motivating features in spacetime physics. 展开更多
关键词 D-spacetime dimensions fractional gravitational field
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Top Quark Polarization and Spin Correlation in the Littlest Higgs Model with T-Parity at the ILC
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作者 杨炳方 李向东 《Communications in Theoretical Physics》 SCIE CAS CSCD 2013年第1期87-94,共8页
In the framework of the littlest Higgs model with T-parity (LHT), we study the top quark spin correlation and polarization at the International Linear Collider (ILC). We find that the top quark polarization asymme... In the framework of the littlest Higgs model with T-parity (LHT), we study the top quark spin correlation and polarization at the International Linear Collider (ILC). We find that the top quark polarization asymmetry δPt and the left-right asymmetry δALR can respectively reach -35% and -37.5% for s = 500 GeV and s = 1000 GeV via e+e- collision, which can reach the observable level at the ILC. By contrast, the spin correlation δC is smaller. The correlation behaviors of these observables at the e+e- collision and the yy, collision will be helpful to distinguish different models and test the LHT model at the ILC. 展开更多
关键词 top quark POLARIZATION spin correlation
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