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Design and Analysis of a Coded Multi-Carrier CDMA System

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The Journal of China Universities of Posts and Telecommunications 2001年第3期8卷 57-61页

作者： ZHENGBao-yu FANGJian departmentofinformationengineering NanjingUniversityofPostsandTelcommunicationsNanjing210003P.R.China departmentofinformationengineering NanjingUniversityofPostsandTelcommunicationsNanjing210003

The multi-carrier code division multiple access (MC-CDMA) system is extended to the coded MC-CDMA system. This system combine the channel error correcting coding (ECC) with MC-CDMA systems, thus sufficiently exploiting the excellent performance of ECC (especially Turbo code) under low SNR. The BER performance of the system in different channels is analyzed, and the simulation results are given.

关键词： frequency division multiplexing code division multiple access error-correcting coding

Handwritten Digits Recognition With Subgroup Neural Network

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The Journal of China Universities of Posts and Telecommunications 1994年第1期1卷 52-56页

作者： WangMinghui PanXinan 等 departmentofinformationengineering BeijingUniversityofpostsandTelecommunicationBeijing100088P.R.China departmentofinformationengineering BeijingUniversityofpostsandTelecommunicationBeijing100088P.

Most of the neural network handwritten digits recognition systems adopt a network with single structure. In this paper,we implement a subgroup neural network structure based on feature description to recognize handwritten digits. It is noticeable that this subgroup network is a hybrid system. The experiment result indicates that the subgroup network gets much better performance than usual single network Structure.

关键词： Neural network Subgroup network Pattern recognition.

Chaotic system for the detection of periodic signals under the background of strong noise

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Chinese Science Bulletin 2003年第5期48卷 508-510页

作者： LIYue YANGBaojun departmentofinformationengineering JilinUniversityChangchun130012China DepartmentofGeophysics JilinUniversityChangchun130026China

We propose a method to study the chaotic sys-tem for the detection of periodic signals in the presence ofstrong background noise. The numerical experiments indi-cate that the chaotic system constructed from the modified Duffing-Holmes equation is sensitive to the weak periodic signal mixed with noise, and it has certain immunity to noise. The signal to noise ratio for the system can reach to about 91 dB.

关键词：信号检测信号处理混乱系统弱周期信号强背景噪声信噪比

Application and Development of Mobile Agent in AN

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The Journal of China Universities of Posts and Telecommunications 2004年第1期11卷 73-78页

作者： XULi ZHENGBao-yu departmentofinformationengineering NanjingUniversityofPostsandTelecommunicationNanjing210003P.R.China

Active Networks represent a significant step in the evolution of packet-switched networks. It aims to move dynamic computation within the network. Mobile agent technology is a novel paradigm for distributed computation. This paper discusses the applicability of mobile agent technology for the development of active networks, both security policy and resource management, and other expected application as well. Based on the discussion, it describes a general mobile agent based Active Network (AN) architecture at last.

关键词： active network mobile agent security management architecture

Important Issues Concerning Computation of Variant Templates for Image Processing

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The Journal of China Universities of Posts and Telecommunications 2004年第2期11卷 1-6页

作者： DONGYu-ning departmentofinformationengineering NanjingUniversityofPostsandTelecommunicationsNanjing210003P.R.China

This paper presents new insights into our previous research on efficient computation of variant templates. The important aspects are analysed in detail, such as convergence, error control and effectiveness of the Taylor's series form of some commonly seen transcendental functions in low level image processing operations. The influence of hardware, as well as the limitations of the proposed approach, is also discussed.

关键词： image processing abstractions variant templates efficient computation

Physical　mechanism　of　the　chaotic　detection　of　the　unknown　frequency　of　weak　harmonic　signal　and　effects　of　damping　ratio　on　the　detection　results

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Chinese Physics B 2004年第9期13卷 1386-1390页

作者：李月杨宝俊邓小英金雷杜立志 departmentofinformationengineering JilinUniversityChangchun130012China CorrespondenceshouldbeaddressedtoYangBao-jun

In the zero-order approximation, we use the perturbation method of parameter with small magnitude to prove that the harmonic frequency in the solution of the equation is close to that of the driving force when the chaotic system from Duffing-Holmes equation stays in the stable periodic state, which is the physical mechanism of the detection of the unknown frequency of weak harmonic signal using the chaotic theory. The result of the simulation experiment shows that the method proposed in this paper, by which one can determine the frequency of the stable system from the number of circulation change of the phase state directionally across a fixed phase state point (x, x) in fixed simulation time period, is successful. Analyzing the effects of the damping ratio on the chaotic detection result, one can see that for different frequency ranges it is necessary to carefully choose corresponding damping ratio α.

关键词： weak harmonic signal unknown frequency chaotic detection damping ratio

On Simulation of Quantum Cryptography

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The Journal of China Universities of Posts and Telecommunications 2002年第4期9卷 13-18页

作者： ZHAOSheng-mei LIFei 等 departmentofinformationengineering NanjingUniversityofPosts&TelecommunicationsUnajing21003P.R.China departmentofinformationengineering NanjingUniversityofPosts&TelecommunicationsUnajing21003P.R.Ch

The simulation of quantum cryptography on classical computers is discussed inthis paper. The methods to express the preparation and measurement of quantum states on currentcomputers are given and the basic algorithms for simulating the quantum key distribution protocolsare presented. All the simulating results of each protocol are given and compared with the theoreticone. It is shown that the simulation results are completely tallied with the theoretic one.

关键词： quantum key distribution quantum-state measurement quantum statepreparation simulation

Blind adaptive identification of FIR channel in chaotic communication systems

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Chinese Physics B 2004年第3期13卷 329-334页

作者：王保云 TommyW.S.Chow K.T.Nb 王保云 TommyW.S.Chow K.T.Nb departmentofinformationengineering NanjingUniversityofPostsandTelecommunicationsNanjing210003China DepartmentofElectronicEngineering CityUniversityofHongKongKowloonHongKongChina

In this paper we study the problem of blind channel identification in chaotic communications. An adaptive algorithm is proposed, which exploits the boundness property of chaotic signals. Compared with the EKF-based approach, the proposed algorithm achieves a great complexity gain but at the expense of a slight accuracy ***, our approach enjoys the important advantage that it does not require the a priori information such as nonlinearity of chaotic dynamics and the variances of measurement noise and the coefficient model noise. In addition,our approach is applicable to the ARMA system.

关键词： chaotic communication blind identification LMS algorithm extended Kalman filtering

Some Growth Rates of Certain Holomorphic Maps

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Chinese Quarterly Journal of Mathematics 2003年第3期18卷 258-263页

作者： YANGQiao QIUJing-hua departmentofinformationengineering NorthChinaInstituteofWaterConservancyandHydroelectricPowerZhengzhou450008China DepartmentofMathematics YellowRiverConservancyTechnicalIn-stituteKaifeng475001China

In this paper we discuss some properties of h olomorphic maps between Kahler manifolds with certain curvature restrictions.

关键词：增长性全纯映射能量密度 Kahler流形曲率余标架 Hermit流形对称性正切向量 Ricci张量