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Asynchronous cooperative communication systems:A survey on signal designs

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Science china(Information Sciences) 2011年第8期54卷 1547-1561页

作者： WANG HuiMing 1,2 & xiA xiangGen 3 1 School of Electronic and Information Engineering, xi’an Jiaotong university, xi’an 710049,china 2.state key laboratory of integrated services networks, xidian university,xi’an 710049, china 3 Department of Electrical and Computer Engineering,university of Delaware,Newark,DE 19716,USA School of Electronic and Information Engineering Xi’an Jiaotong University Xi’an China state key laboratory of integrated services networks Xidian University Xi’an China Department of Electrical and Computer Engineering University of Delaware Newark USA

Cooperative communications is a promising technique for future high speed wireless *** systems may be formulated as virtual multi-input multi-output (MIMO) systems where spatial/cooperetive diversity is a key advantage. However,different from MIMO systems,one of the major chal- lenges for cooperative communications systems is that the cooperative transmissions in cooperative systems may be neither time nor frequency synchronized,since the transmissions are from multiple cooperative nodes at different *** existing signal designs for co-located MIMO systems may not be able to collect the cooperative diversity in cooperative communications *** paper gives an overview of recent research efforts on combating the time and frequency asynchronism of the cooperative communication *** focus on the signal designs (or space-time codings/modulations) to achieve full cooperative diversity,and summarize some of the resent distributed space-timing coding and space-frequency coding techniques to combat timing errors and frequency offsets,and in the meantime to achieve full cooperative diversity,in both one-way and two-way cooperative networks.

关键词： cooperative communications time and frequency offsets space-time coding space-frequency codes full cooperative diversity linear receiver

Price-based interference avoidance game in the Gaussian interference channel

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Science china(Information Sciences) 2012年第2期55卷 301-311页

作者： JING ZhenHai1,BAI BaoMing1 & MA xiao2 1state key laboratory of integrated services networks,xidian university,xi'an 710071,china 2Department of Electronics and Communication Engineering,Sun Yat-sen university,Guangzhou 510275,china state key laboratory of integrated services networks Xidian University Xi’an China Department of Electronics and Communication Engineering Sun Yat-sen University Guangzhou China

This paper considers a distributed interference avoidance problem employing frequency assignment in the Gaussian interference channel(IC).We divide the common channel into several sub-channels and each user chooses one sub-channel for transmission in such a way that the total interference in the IC is *** mechanism named interference avoidance in this paper can be modeled as a competitive game *** a completely autonomous distributed iterative algorithm called distributed interference avoidance algorithm(DIA)is adopted to achieve the Nash equilibrium(NE)of the *** to the self-optimum,the DIA is a sub-optimal ***,through introducing an optimal compensation(or price)into the competitive game model,we successfully develop a compensation-based game model to approximate the optimal interference avoidance ***,an optimal algorithm called iterative optimal interference avoidance algorithm(IOIA)is proposed to reach the optimality of the interference avoidance *** analyze the implementation complexity of the proposed algorithm which is only O(N),with N standing for the number of users in the *** also give the proof on the convergence of the proposed *** performance upper bound and lower bound are derived for the IOIA *** simulation results show that the IOIA does reach the optimality under the condition of interference avoidance mechanism.

关键词： interference channel interference avoidance game theory

A novel method for the improvement of power efficiency in high peak-to-average-power ratio communication systems

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Science china(Information Sciences) 2010年第8期53卷 1697-1702页

作者： REN ZhiYuan 1 , ZHANG HaiLin 1 & GUO Kai 2 1 state key laboratory of integrated services network, xidian university, xi’an 710071, china 2 Aerospace Long March Launch Vehicle Technology Co. Ltd., Beijing 100076, china state key laboratory of integrated services network Xidian University Xi’an China Aerospace Long March Launch Vehicle Technology Co. Ltd. Beijing China

To solve the problem of low power efficiency of power amplifiers (PA) in the high peak-to-averagepower ratio (PAPR) communication system, a novel signal decomposed amplifier structure has been proposed in order to decrease the energy consumption and increase the power efficiency of PA. The high PAPR signal can be decomposed into several low PAPR branch signals, linearized and amplified in parallel. This structure can reduce the PAPR of branch signals and improve the power efficiency of PA. The simulation results indicate that the power efficiency will be remarkably increased.

关键词： Green Radio power amplifier signal decomposed

Construction of nonbinary quantum cyclic codes by using graph method

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Science in china(Series F) 2005年第6期48卷 693-702页

作者： LIU Tailin1,2,3, WEN Qiaoyan1 & LIU Zihui4 1. School of Science, Beijing university of Posts and Telecommunications, Beijing 100876, china 2. state key laboratory of integrated services network, xidian university, xi’an 710071,china 3. Shandong Finance Institute, Jinan 250014, china 4. School of Mathematical Sciences, Peking university, Beijing 100871, china School of Science Beijing University of Posts and Telecommunications Beijing China state key laboratory of integrated services network Xidian University Xi’an China Shandong Finance Institute Jinan China School of Mathematical Sciences Peking University Beijing China

Using the graph method proposed by Schlingemann and Werner, this paper introduces a technique to construct nonbinary quantum cyclic codes and provides a specific example. We also construct the quantum codes [[8, 2, 4]... 详细信息

关键词： nonbinary quantum stabilizer codes quantum cyclic codes

A NEW EFFICIENT ID-BASED PROXY BLIND SIGNATURE SCHEME

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Journal of Electronics(china) 2008年第2期25卷 226-231页

作者： Ming Yang Wang Yumin state key Lab of integrated Service network Xidian University Xi＇an 710071 China

In a proxy blind signature scheme,the proxy signer is allowed to generate a blind signature on behalf of the original signer. The proxy blind signature scheme is useful in several applications such as e-voting,e-payment,etc. Recently,Zheng,et al. presented an IDentity(ID) -based proxy blind sig-nature. In this paper,a new efficient ID-based proxy blind signature scheme from bilinear pairings is proposed,which can satisfy the security properties of both the proxy signatures and the blind signature schemes. Analysis of the scheme efficiency shows that the new scheme is more efficient than Zheng,et al.'s scheme. The proposed scheme is more practical in the real world.

关键词： Blind signature Proxy signature Bilinear pairing

Microstructures and mechanical properties of directionally solidified multi-element Nb-Si alloy

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Progress in Natural Science:Materials International 2011年第2期21卷 146-152页

作者： Qiang HUANG~(1,2),xi-ping GUO~2,Yong-wang KANG~1,Jin-xia SONG~1,Shi-yu QU~1,Ya-fang HAN~1 1.National key laboratory of Science and Technology on Advanced High Temperature Structural Materials, Beijing Institute of Aeronautical Materials,Beijing 100095,china 2.state key laboratory of Solidification Processing,Northwestern Polytechnical university,xi'an 710072,china National key laboratory of Science and Technology on Advanced High Temperature Structural Materials Beijing Institute of Aeronautical Materials Beijing 100095 China state key laboratory of Solidification Processing Northwestern Polytechnical University Xi'an 710072 China

Nb-Si system in-situ composites with nominal composition of Nb-21Ti-16Si-7Cr-3Al-2Hf（mole fraction,%） were prepared by directional solidification technology in an optical floating zone furnace at the growth rates of 3,5,8 and 12 mm/*** microstructures and mechanical properties were investigated as a function of the growth *** results show that the solidification microstructures consist of Nb solid solution（Nbss）,α-Nb5Si3andβ-*** with high aspect ratio grow continuously and straightly when the growth rate is 5mm/h;lower or higher growth rates are disadvantageous for the formation of favorable directional *** compressive strength at 1 250℃and room-temperature fracture toughness of the specimen with the growth rate of 5 mm/h that exhibits excellent mechanical properties are 415 MPa and 22.4 MPa·m1/2,respectively.

关键词： Nb-Si system in-situ composite directional solidification microstructure mechanical property

Fair Non-Repudiation for Web services Transactions

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Wuhan university Journal of Natural Sciences 2010年第5期15卷 385-392页

作者： SU Ruidan,FU Shaofeng,ZHOU Lihua key laboratory of Computer network and Information Security of the Ministry of Education,xidian university,xi’an 710071,Shaanxi,china key laboratory of Computer network and Information Security of the Ministry of Education Xidian University Xi’an Shaanxi China

To safeguard the interests of transacting parties,non-repudiation mechanisms need to assure fairness and *** non-repudiation service currently implemented usually does not consider the requirement of fairness and the fair non-repudiation protocols to date can not be suitably applied in real environment due to its complex *** paper discusses the transaction-oriented non-repudiation requirement for Web services transaction,analyzes the constraints of the traditional model for the available fair non-repudiation protocols and designs a new Online-TTP fair non-repudiation *** new protocol provides a fair non-repudiation solution to secure Web services transactions and can be embedded into a single Web service *** protocol adopts evidence chained to decreasing the overhead of evidence verification and management and alleviates the overhead of certificate revocation checking and time-stamp generation for *** protocol has strong fairness,timeliness,efficiency and practicability.

关键词： fair non-repudiation Web services transaction evidence chaining timeliness

Quantum Authentication Based on the Lengthened String Scheme

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The Journal of china Universities of Posts and Telecommunications 2004年第Z1期11卷 14-17,25页

作者： GUO Fen-zhuo~(1,2), WEN Qiao-yan~1, ZHU Fu-chen~3 1.School of Science, Beijing university of Posts and Telecommunications, Beijing 100876, P.R. china 2.state key laboratory of integrated services network, xidian university, xi’an 710071, P.R. china 3.National laboratory for Secure Communication, Chengdu 610041, P.R. china School of Science Beijing University of Posts and Telecommunications Beijing 100876 P.R. China state key laboratory of integrated services network Xidian University Xi'an 710071 P.R. China School of Science Beijing University of Posts and Telecommunications Beijing 100876 P.R. China National laboratory for Secure Communication Chengdu 610041 P.R. China

Assuming there is a shared string between the users, we present a novel scheme, the lengthened string scheme (LSS), where the shared string is lengthened firstly by a specially designed algorithm, then some special treatments are applied on the lengthened one before it is used to authenticate. Based on the lengthened string scheme (LSS) we propose a quantum authentication protocol using entanglements. And the robustness of our protocol is discussed. In fact all the quantum key distribution protocols can do identification simultaneously based on the LSS.

关键词： quantum cryptography quantum authentication quantum key distribution LSS

Multiary turbo code fitting for unitary space-time modulation and its MAP decoding algorithm

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Science china(Information Sciences) 2010年第12期53卷 2610-2619页

作者： ZHANG DaPeng 1,2,3,LU Ju 1,XU HongJi 1 & ZHANG xingYu 1 1 School of Information Science and Engineering,Shandong university,Jinan 250100,china 2.state key laboratory of integrated services networks,xidian university,xi'an 710077,china 3 Department of Avionics Engineering,First Aeronautical College of the Air Force,xinyang 464000,china School of Information Science and Engineering Shandong University Jinan China state key laboratory of integrated services networks Xidian University Xi’an China Department of Avionics Engineering First Aeronautical College of the Air Force Xinyang China

Unitary space-time modulation(USTM) fits for rapid Rayleigh flat fading channels as it can realize wireless communication when neither the transmitter nor the receiver knows the channel state information(CSI).However,an intrinsic problem is that only when the signal-to-noise ratio(SNR) is high can it give an ideal bit error rate(BER) *** existing bit-wise processing scheme of the combination of turbo code and USTM improves the BER performance and results in an unacceptable calculation complexity,storage and time delay *** this paper,we propose a multiary processing scheme and its corresponding multiary MAP decoding *** results verify that our scheme can reduce the system complexity while keep a good BER ***,we present the first analysis of the reason for the BER performance deterioration of the combination scheme at low SNR with the help of the definition of USTM.

关键词： multiple-input multiple-output unitary space-time modulation turbo code MAP decoding diversity