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Combining Digital Watermarks with Two-Color Bitmap Image

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The Journal of china Universities of posts and Telecommunications 2000年第Z1期 31-35页

作者： SAAD A Amer, YANG Yi-xian (information Security Center, beijing university of posts and Tele{4.s, beijing 100876, P.R. china)

A technology for combining digital watermarks with two-color bitmap image based on the threshold watermarking method is presented. Our technology doesn’t add any thing to the digital media, but combines the watermarks in two-color bitmap image by looking for some characteristic values in the bitmap and uses the relationship between the watermarks and the characteristic values to prove the copyright protection. The choice of the characteristic values depends on the choice of a cryptographic key known by the owner of the bitmap. The benefit of using a cryptographic key is to combine the watermarks with the bitmap in a high secure way.

关键词： digital watermarks information hiding copyright protection

A 3-D Polarization Quadrature Amplitude Modulation Method and Constellation Mapping

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china communications 2015年第10期12卷 16-26页

作者： SUN Xuehong ZHANG Haiying ZENG Zhimin GUO Caili beijing Key Laboratory of Network System Architecture and Convergence School of Information and Communication EngineeringBeijing University of Posts and Telecommunications Key Laboratory of Intelligent Sensing for Desert information School of Physics Electrical EngineeringNingxia University

As a new three-dimensional(3-D)modulation,Polarization Quadrature Amplitude Modulation(PQAM) can be regarded as the combination of Pulse amplitude modulation(PAM) and Quadrature Amplitude Modulation(QAM) *** can better improve the digital communication efficiency and reduce the Symbol error rate(SER) of the system than one-dimensional or two-dimensional modulation *** to design a feasible constellation is the most concerned problem of PQAM *** paper first studies the relationship between the SER theoretical value of PQAM and the distribution of M and N,proposes a new M,N allocation ***,a new and straightforward design method of constructing higher-level 3-D signal constellations,which can be matched with the PQAM,and the constellation can divided into three different structures according to the ary for ***,the simulation results show that:in PQAM system,the modulation scheme and the constellation mapping scheme are proposed in this paper which can effectively reduce the system SER and improve the anti-noise performance of the system.

关键词： polarization quadrature amplitude modulation minimum euclidean distance symbol error probability 3-D constellation

RPPK modulation with high data rates

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Science china(information Sciences) 2010年第2期53卷 344-354页

作者： LI Bin , ZHOU Zheng & ZOU WeiXia Key Laboratory of Universal Wireless communications, Ministry of Education Wireless Network Laboratory, beijing university of posts and Telecommunications, beijing 100876, china 1. Key Laboratory of Universal Wireless communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China2. Wireless Network Laboratory Beijing University of Posts and Telecommunications Beijing 100876 China

With the development of communication technology, the precious frequency spectrum is becoming more and more crowded. Exploiting the particular filter with zero group delay, ultra narrow band (UNB) modulation is intended for acquiring the high frequency efficiency. Unfortunately, this UNB filter is confronted with great challenges from the classical communication theories. The validation on its realization is also difficult. This paper proposes a novel UNB modulation, namely random pulse position keying (RPPK). It is demonstrated from analysis that there is no inessential discrete spectral line in modulated signal’s power density spectrum (PDS), and the UNB filter has been successfully avoided. Consequently, RPPK is rather explicit in theory and simple in implementation. As is shown by the simulation, the frequency utilization of RPPK can even reach 100 bits/s/Hz. Its optimum receiving performance is slightly inferior to BPSK, yet is much superior to that of other UNB modulations such as VMSK/2. Moreover, multi-access and confidentiality are additional benefits to UNB users.

关键词： UNB modulation frequency utilization efficiency RPPK PDS

On Personal communication

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The Journal of china Universities of posts and Telecommunications 1995年第1期2卷 50-54页

作者： Zhou Jiongpan(Department of information engineering, beijing university of {4. and Telecommunications beijing 100088, P.R. china) Department of information engineering Beijing University of Posts and Telecommunications Beijing 100088 P. R. China

This paper first gives a definition for personal communication, then discusses some key problems to besolved in realizing PC and lastly gives some personal suggestions.

关键词： personal communication multi-access,satellite communication

An Adaptive Neural Network Model for Nonlinear Programming Problems

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Acta Mathematicae Applicatae Sinica 2002年第3期18卷 377-388页

作者： Xiang-sun Zhang, Xin-jian Zhuo, Zhu-jun JingAcademy of Mathematics and System Sciences, Chinese Academy of Sciences, beijing 100080, chinaschool of information {4., beijing university of posts and Telecommunications, beijing 100876, chinaHunan Normal university, Changsha 4.0081, china & Academy of Mathematics and System Sciences, Chinese Academy of Sciences, beijing 100080, china Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing China school of information engineering Beijing University of Posts and Telecommunications Beijing China Hunan Normal university Changsha China

In this paper a canonical neural network with adaptively changing synaptic weights and activation function parameters is presented to solve general nonlinear programming problems. The basic part of the model is a sub-network used to find a solution of quadratic programming problems with simple upper and lower bounds. By sequentially activating the sub-network under the control of an external computer or a special analog or digital processor that adjusts the weights and parameters, one then solves general nonlinear programming problems. Convergence proof and numerical results are given.

关键词： Adaptive neural network canonical neural network general nonlinear programming

A New Image Process CNN

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A New Image Process CNN

Analysis of a kind of quantum cryptographic schemes based on secret sharing

中国运筹学会第七届学术交流会

作者： Zhuo Xinjian school of information engineering, beijing {4. of posts and,Telecommunications, beijing,100876, china

A set of cellular neural network (CNN) templates are proposed. ThisCNN can change each black pixel into thite and vice-versa, and translate the changedimages in each of 8 compass directions at the same time, respectively Robustnessanalysis gives template parameter inequalities which guarantee the correspondingCNN working well for performing prescribed tasks. Simulation examples are given.

关键词： cellular neural network(CNN) bobustness translation

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Science china(Physics,Mechanics & Astronomy) 2009年第9期52卷 1313-1316页

作者： ZHANG XingLan1 & JI DongYao2 1 College of Computer Science and Technology, beijing university of Technology, beijing 100124. china 2 State Key Laboratory of {4. Security, Graduate university of Chinese Academy of Sciences, beijing 10004., china College of Computer Science and Technology Beijing University of Technology Beijing 100124 China State Key Laboratory of information Security Graduate University of Chinese Academy of Sciences Beijing 100049 China

Recently, Yang et al. proposed a kind of quantum cryptographic schemes based on secret sharing. The main idea is drawn from the case, where any n participants who share a secret K can co-operate as K does. This process can be applied to encryption, authentication, signature and so on. Unfortunately, since there is no identity authentication of the share's holder, these schemes inherit the limitation of secret sharing in practice. If some participants do not follow the protocol, the protocol would be a failure at last. Moreover, these schemes encounter another serious attack. Any two participants can co-operate to defeat the schemes by sending different shares to the parties unknown to the distributor of the secret K, such that these parties can execute the protocol as well. The attack proves that it is not enough for quantum cryptographic schemes that only the secret key is secure.

关键词： quantum identity authentication quantum secure direct communication quantum signature secret sharing

The Algorithm and Its Application of a Multi-Channel Adaptive Decision-Feedback Equalizer

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The Journal of china Universities of posts and Telecommunications 2003年第4期10卷 59-64页

作者： ZHANG Yu-liang,WU Wei-ling,TIAN Bao-yu,HE Zhi-qiang,GU Xin-yu(school of information engineering, beijing {4. of posts & Telecommunications, beijing 100876, P.R.china) school of information engineering Beijing University of Posts & Telecommunications 北京 100876

In digital radio communication, diversity reception can combat flat fadingand adaptive equalization can combat Inter-Symbol Interference (ISI). In this paper, the structureand algorithm of a multi-channel equalizer with combined diversity reception and adaptiveequalization techniques are studied. Because Phase-Looked-Loops (PLL) are embedded in the equalizer,this equalizer is suitable for coherent communication in channels with high phase *** Carlo simulation is used to test its performance and the results show that a multi-channeldecision-feedback-equalizer has better performance than a single-channeldecision-feedback-equalizer, and the results of processing high-speed digital underwatercommunication signals demonstrate this farther.

关键词： multi-channel decision-feedback-equalizer diversity reception coherentcommunications

Efficient Mechanisms to Improve TCP Performance over OBS Networks

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china communications 2010年第2期7卷 87-91页

作者： Hong Xiaobin, Zhou Jun, Wu Jian, Guo Hongxiang, Zuo Yong, Xu Kun, Lin Jintong Key Laboratory of information Photonics and Optical communications, Ministry of Education Institute of Optical communications and Optoelectronics, beijing {4. of posts and Telecommunications, beijing 100876, china Key Laboratory of information Photonics and Optical communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

Transmission Control Protocol (TCP) performance over Optical Burst Switching (OBS) is experimentally investigated on an OBS network testbed, concluding that burst losses will lead to a significant drop in the available TCP bandwidth. Two mechanisms are introduced to improve TCP performance. One is concerning the burst assembly optimization and another is based on the novel assembly and scheduling mechanism to reduce the burst losses.

关键词： OBS ACK TCP burst loss probability scheduling algorithm