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Low-complexity distributed differential spacetime coding scheme for amplify-and-forward cooperative networks

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Science in china(Series F) 2009年第8期52卷 1418-1427页

作者： YU XiangBin1,2, BI GuangGuo3 & XU WeiYe4 1 College of Information Science and Technology, Nanjing university of Aeronautics and Astronautics, Nanjing 210016, china 2 Department of Electronic Engineering, City university of Hong Kong, Hong Kong, china 3 National Mobile communications Research Laboratory, Southeast university, Nanjing 210096, china 4 Department of Communication Engineering, Nanjing Institute of Technology, Nanjing 211167, china College of Information Science and Technology Nanjing University of Aeronautics and Astronautics Nanjing China Department of Electronic Engineering City University of Hong Kong Hong Kong China National Mobile communications Research Laboratory Southeast University Nanjing China Department of Communication Engineering Nanjing Institute of Technology Nanjing China

By introducing a space-time coding scheme based on amicable orthogonality, we develop a distributed differential space-time coding scheme with the amplify-and-forward （AF） method for wireless cooperative networks. The scheme requires no knowledge of the channel state information at both transmitters and receivers, and effectively decreases the realization complexity due to no channel estimation. Moreover, it has lower decoding complexity and higher coding advantage than the existing scheme, thus avoiding the shortcoming of exponential decoding complexity of some existing schemes. According to the pairwise error probability （PEP） analysis of the system, the power allocations of source and relay terminals are jointly optimized, and as a result, the PEP is minimized, which will provide a helpful guideline for system design. Numerical calculation and simulation results show that the developed scheme is superior to the existing scheme. Moreover, the scheme with optimal power allocation yields obvious performance improvement over that with equal power allocation.

关键词： differential space-time coding cooperative communication amplify-and-forward method power allocation

Joint subcarrier and power allocation in uplink OFDMA systems based on stochastic game

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Science china(Information Sciences) 2010年第12期53卷 2557-2566页

作者： WU Dan 1,CAI YueMing 1,2 & SHENG YanMing 1 1 Institute of communications Engineering,PLA university of Science and Technology,Nanjing 210007,china 2 National Mobile communications Research Laboratory,Southeast university,Nanjing 210096,china Institute of communications Engineering PLA University of Science and Technology Nanjing China National Mobile communications Research Laboratory Southeast University Nanjing China

In uplink orthogonal frequency division multiplexing access(OFDMA) systems,efficient resource allocation can greatly improve system ***,in this paper,we present a game-theoretical approach to achieve a joint subcarrier and power allocation in a distributed ***,the subcarrier allocation problem is modeled as a multi-player discrete,stochastic and finite strategy game,where each of the subcarriers is viewed as a player to choose the most satisfying *** subcarriers of each user are allocated with equal *** the proposed game model,on the one hand,we exploit the support and programming methods to obtain the Nash equilibriums,and analyze their theoretical *** the other hand,we propose a lowcomplexity algorithm based on the linear reward-inaction(L R-I) algorithm to search for the Nash *** the relationship between the convergence results of this algorithm and the Nash equilibriums is *** simulation results demonstrate the effectiveness of the resource allocation game model and algorithm.

关键词： stochastic game OFDMA subcarrier allocation power allocation learning automata linear reward-inaction

Non-Lie Symmetry Groups of (2+1)-Dimensional Nonlinear Systems

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communications in Theoretical Physics 2006年第12期46卷 1005-1010页

作者： MA Hong-Cai~1 and LOU Sen-Yue~(2,3) 1 Department of Mathematics, Donghua university, Shanghai 200051, china 2 Department of Physics, Shanghai Jiao Tong university, Shanghai 200030, china 3 Center of Nonlinear Science, Ningbo university, Ningbo 315211, china Department of Mathematics Donghua University Shanghai 200051 China Department of Physics Shanghai Jiao Tong University Shanghai 200030 China Center of Nonlinear Science Ningbo University Ningbo 315211 China

A modified direct method is developed to find finite symmetry groups of nonlinear mathematical physics systems. Applying the modified direct method to the well-known(2+1)-dimensional asymmetric Nizhnik-Novikov-Vesselov equation and Nizhnik-Novikov-Vesselov equation, both the Lie point symmetry groups and the non-Lie symmetry groups are obtained. The Lie symmetry groups obtained via traditional Lie approaches are only special cases. Furthermore, the expressions of the exact finite transformations of the Lie groups are much simpler than those obtained via the standard approaches.

关键词： symmetry groups CK direct method symmetries exact solution

On the Higher-order Nonlinear Ginzburg-Landau System in n Spatial Dimensions

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communications in Nonlinear Science and Numerical Simulation 1998年第1期3卷 15-19页

作者： Haiyang HUANG (Dept.of Math.,beijing Normal university,beijing 100875,china) E mail:hhywsg@*** Depatment of Mathematics Beijing Normal University Beijing 100875 China

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅＧｉｎｚｂｕｒｇＬａｎｄａｕｅｑｕａｔｉｏｎｇｏｖｅｒｎｓｔｈｅｆｉｎｉｔｅａｍｐｌｉｔｕｄｅｅｖｏｌｕｔｉｏｎｏｆｉｎｓｔａｂｉｌｉｔｙｗａｖｅｓｉｎａｌａｒｇｅｖｅｒｉｔｙｏｆｄｉ... 详细信息

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅＧｉｎｚｂｕｒｇＬａｎｄａｕｅｑｕａｔｉｏｎｇｏｖｅｒｎｓｔｈｅｆｉｎｉｔｅａｍｐｌｉｔｕｄｅｅｖｏｌｕｔｉｏｎｏｆｉｎｓｔａｂｉｌｉｔｙｗａｖｅｓｉｎａｌａｒｇｅｖｅｒｉｔｙｏｆｄｉｓｉｐａｔｉｖｅｓｙｓｔｅｍｗｈｉ...

关键词： generalized solution global attractor Hausdorff dimension fractal dimension Ginzburg Landau equation

VCO clock synchronization loop combined with dispersion equalization in optical coherent receivers

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The Journal of china Universities of Posts and Telecommunications 2010年第5期17卷 122-128页

作者： FAN Yang-yang,CHEN Xue,ZHOU Xian,ZHOU Wei-qin,ZHU Hai,LI Zhi-yu Key Laboratory of Information Photonics and Optical communications,Ministry of Education,beijing university 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

In optical coherent receivers,the timing error detector （TED） in synchronization loop can not work normally when signal is distorted by large *** paper proposes a novel clock synchronization scheme which adds a butterfly-structured adaptive equalizer to the loop to fulfill synchronizations,equalizations and polarization de-multiplexing of two polarization states simultaneously under the control of single voltage-controlled oscillator （VCO）.Simulink simulation demonstrates the rationality and the feasibility of the combined loop with single VCO.

关键词： optical coherent receiver synchronization dispersion equalization

Identifying online traffic based on property of TCP flow

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The Journal of china Universities of Posts and Telecommunications 2009年第3期16卷 84-88页

作者： HONG Min-huo,GU Ren-tao,WANG Hong-xiang,SUN Yong-mei,JI Yue-feng Key Laboratory of Optical communications and Lightwave Technologies,beijing university of Posts and Telecommunications,beijing 100876,china Key Laboratory of Optical communications and Lightwave Technologies Beijing University of Posts and Telecommunications Beijing 100876 China

Classification of network traffic using port-based or payload-based analysis is becoming increasingly difficult when many applications use dynamic port numbers, masquerading techniques, and encryption to avoid detection. In this article, an approach is presented for online traffic classification relying on the observation of the first n packets of a transmission control protocol （TCP） connection. Its key idea is to utilize the properties of the observed first ten packets of a TCP connection and Bayesian network method to build a classifier. This classifier can classify TCP flows dynamically as packets pass through it by deciding whether a TCP flow belongs to a given application. The experimental results show that the proposed approach performs well in online Internet traffic classification and that it is superior to naive Bayesian method.

关键词： network traffic classification inter-arrival time TCP flow Bayesian network

Evolution of Nielsen-Olesen's String from Chern-Simons Field Theory

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communications in Theoretical Physics 2007年第7期48卷 147-150页

作者： DUAN Yi-Shi Institute of Theoretical Physics,Lanzhou university,Lanzhou 730000,chinaSHI Xu-Guang College of Science,beijing Forestry university,beijing 100083,china Institute of Theoretical Physics Lanzhou University Lanzhou 730000 China College of Science Beijing Forestry University Beijing 100083 China

We study the topology of Nielsen-Olesen's local field theory of single dual *** on the Chern-Simons field theory in three dimensons,we find many strings that can form world sheets in four *** stringshave important relation to the zero point of the complex scalar *** world sheets of strings can be expressed bythe topological invariant number,Hopf index,and Brower ***-Goto's action is obtained from the Nielsen'saction definitely by using φ-mapping theory.

关键词： φ-mapping theory dual string Nambu-Goto’s action Hopf index Brower degree

Existence of entire explosive positive radial solutions of sublinear elliptic systems

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communications in Nonlinear Science and Numerical Simulation 2001年第2期6卷 88-92页

作者： Zuodong YANG and Qishao LU Department of Applied Mathematics, Peking university of Aeronautics and Astronautics, beijing 100083, china Department of Applied Mathematics Peking University of Aeronautics and Astronautics Beijing 100083 China

In this paper, our main purpose is to establish the existence of entire explosive positive radial solutions of quasilinear elliptic systems. The main results of the present paper are new and extend the previously know... 详细信息

关键词： quasilinear elliptic system entire explosive positive solution existence

On Catastrophe and Cavitation for SphericalCavity

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communications in Nonlinear Science and Numerical Simulation 1999年第4期4卷 249-254页

作者： Ming JIN Kefu HUANG Jike WU(Department of Mechanics and Engineering Science, Peking university, beijing 100871,china) Department of Mechanics and Engineering Science Peking University Beijing 100871 China

IntroductionInrecelltyears,theresearchesoncavitationandcatastropheofacavitysu***therwithbifllrcationtheory... 详细信息

IntroductionInrecelltyears,theresearchesoncavitationandcatastropheofacavitysu***therwithbifllrcationtheory...

关键词： nonlinearity bifurcation Hooke material