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SQUARE attack on block ciphers with low algebraic degree

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Science china(Information Sciences) 2010年第10期53卷 1988-1995页

作者： SUN Bing 1 , LI RuiLin 1 , QU LongJiang 1,3.& LI Chao 1,2,3.1 Science College of National University of Defense technology, Changsha 410073. china 2.state {3. laboratory of Information Security, Graduate University of Chinese academy of Sciences, beijing 100049, china 3.National mobile communications Research laboratory, Southeast University, Nanjing 210096, china 1. Science College of National University of Defense technology Changsha 410073 China3. National Mobile Communications Research Laboratory Southeast University Nanjing 210096 China2. State Key Laboratory of Information Security Graduate University of Chinese Academy of Sciences Beijing 100049 China

By using an algebraic method, the mathematical foundation of SQUARE attack is studied in this paper. We point out that a SQUARE distinguisher exists if and only if the degree of the polynomial function between n-bit input which is active and n-bit output which is balanced is 2 n-2. And the algebraic method can also be used to determine the property of a balanced set after passed through a nonlinear S-box, by which in some cases we can find a SQUARE distinguisher with more rounds. The validity of SQUARE attack and the influence of the choice of S-box are also studied. If the round function of a Feistel cipher has a low algebraic degree, a SQUARE attack cannot recover the right keys in some special cases. However, SQUARE attack on SPN ciphers always holds. The relations among SQUARE attack and some other cryptanalytic method are studied, showing that if a cipher is breakable by SQUARE attack, then it is also breakable by the interpolation attack.

关键词： SQUARE attack interpolation attack integral attack block cipher

2.5-dimensional angle potential field algorithm for the real-time autonomous navigation of outdoor mobile robots

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Science china(Information Sciences) 2011年第10期54卷 2100-2112页

作者： QIU Quan 1,3.& HAN JianDa 2 1 beijing Research Center of Intelligent Equipment for Agriculture,beijing 100097,china {3. key laboratory of Robotics,Shenyang Institute of Automation,Chinese academy of Sciences,Shenyang 110016,china 3.National Research Center for Intelligent Agricultural Equipment,beijing 100097,china 1. beijing Research Center of Intelligent Equipment for Agriculture Beijing 100097 China3. National Research Center for Intelligent Agricultural Equipment Beijing 100097 China2. State Key Laboratory of Robotics Shenyang Institute of Automation Chinese Academy of Sciences Shenyang 110016 China

A new real-time algorithm for the autonomous navigation of mobile robots equipped with laser scanners is proposed in this *** from the existing algorithms designed for 2-dimensional navigation problems,the new algorithm introduces the height information of the obstacles into the guidance process and behaves as a 2.5-dimensional angle potential field algorithm (2.5D-APF) to fulfill the navigation requirements under complex outdoor terrain ***,one laser scan is partitioned into two kinds of function sectors: guidance sector and inspecting ***,the guidance sector and the inspecting sectors are reconstructed to form a virtual guidance scan,where the 2.5D information is taken into ***,the conventional APF is improved to analyze the virtual guidance scan and generate the navigation *** new algorithm is tested on a tracked mobile robot,and the experimental results validate the proposed algorithm.

关键词： robot 2.5-dimensional outdoor real-time autonomous navigation

Hybrid CSI-RS Transmission Mechanism-Based 3. Beamforming Scheme for FDD Massive MIMO System

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china communications 2016年第S2期13卷 109-119页

作者： Fangchao Zhang Shaohui Sun Qiubin Gao Hui Li School of Electronic and Information Engineering Beihang University state key laboratory of {3. mobile communications China Academy of Telecommunications Technology

Massive multiple-input multipleoutput(MIMO) refers to the idea that equipping base station(BS) with a large number of antenna elements,and features the ability of three dimensional(3.) beamforming technique to enable improvement in system *** prior works on massive MIMO generally rely on a common assumption of the whole channel characteristics are perfectly known at both user equipment(UE) and BS,however,this is quite difficult to realize in practical frequency division duplexing(FDD) system since the channel state information reference signal(CSIRS) overhead and CSI feedback overhead are proportional to the number of antenna *** this paper,two hybrid CSI-RS transmission mechanism-based 3. beamforming schemes are proposed in FDD massive MIMO system,in which non-beamformed CSI-RS configuration is utilized in conjunction with beamformed CSIRS *** the proposed schemes,an angle quantization-based vertical codebook and a DFT-based horizontal codebook are designed,respectively,and an eigenvalue decompositionbased precoding matrix indicator(PMI)selection algorithm is also proposed for CSI *** results show that the proposed 3. beamforming schemes achieve significant improvement in system capacity without incurring excessive CSI-RS overhead.

关键词： massive MIMO 3. beamforming CSI-RS codebook feedback PMI

A Sensor-Service Collaboration Approach for Target Tracking in wireless Camera Networks

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china communications 2017年第7期14卷 44-56页

作者： Shuai Zhao Le Yu state key laboratory of Networking and Switching {3. Beijing University of Posts and Telecommunications china mobile Information Security Center

mobile target tracking is a necessary function of some emerging application domains, such as virtual reality, smart home and intelligent healthcare. However, existing portable devices for target tracking are resource intensive and high-cost. Camera tracking is an effective location tracking way for those emerging applications which can reuse the existing ubiquitous video monitoring system. This paper proposes a dynamic community-based camera collaboration(D3.) framework for target location and tracking. The contributions of D3. mainly include that(1) nonlinear perspective projection model is selected as the camera sensing model and sequential Monte Carlo is employed to predict the target location;(2) a dynamic collaboration scheme is proposed, it is based on the local community-detection theory deriving from social network analysis. The performance of proposed approach is validated by both synthetic datasets and real-world application. The experiment results show that D3. meets the versatility, real-time and fault tolerance requirements of target tracking applications.

关键词： service collaboration camera tracking community detection sequential monte carlo

A survey of next generation mobile communications researchin china

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Chinese Science Bulletin 2011年第5期56卷 2875-2888页

作者： TIAN JinFeng 1,2 , ZHENG XiaoYing 2,3., HU HongLin 1,2 YOU XiaoHu 1,3.1 Shanghai Research Center for wireless communications (WiCO), Shanghai 2003.5, china 2 Shanghai Institute of Microsystem and Information {3. (SIMIT), Chinese academy of Sciences (CAS), Shanghai 200050, china 3.National mobile communications Research laboratory, Southeast University (SEU), Nanjing 210096, china Shanghai Research Center for wireless communications (WiCO) Shanghai Institute of Microsystem and Information technology (SIMIT) Chinese Academy of Sciences (CAS) National mobile communications Research laboratory Southeast University (SEU)

With the rapid development of wireless communication networks, the fourth generation (4G) has emerged to move beyond the limitations of the third generation (3.), with increased bandwidth, enhanced quality of services, and reduced costs of resources. In this paper, we discuss the key technologies of 4G and focus on surveying the ongoing research in 4G communications in {3.. The 4G technologies under investigation include multicarrier transmission, multiple antenna techniques, carrier aggregation, relays, cognitive radio, distributed antenna systems, network convergence, and network self-optimization. These technologies are the building blocks of 4G and contribute largely to the requirements of International mobile Telecommunications Advanced (IMT-Advanced). For each technology, its benefits, research topics, and some existing approaches are examined. Finally, we briefly discuss the challenges and future research issues in 4G systems.

关键词：下一代移动通信中国无线通信网络分布式天线系统 4G系统多载波传输国际移动通信认知无线电

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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, {3. 2 Aerospace Long March Launch Vehicle technology Co. Ltd., beijing 100076, {3. 1. state key laboratory of Integrated Services Network Xidian University Xi’an 710071 China2. Aerospace Long March Launch Vehicle Technology Co. Ltd. Beijing 100076 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

Asymptotic Analysis for Low-Resolution Massive MIMO Systems with MMSE Receiver

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china communications 2018年第9期15卷 189-199页

作者： Kai Liu Cheng Tao Liu Liu Tao Zhou Yinsheng Liu Institute of Broadband wireless mobile communications School of Electronics and Information Engineering Beijing Jiaotong University National mobile communications Research laboratory Southeast University state key laboratory of Rail Traffic Control and Safety Beijing Jiaotong University

The uplink achievable rate of massive multiple-input-multiple-output(MIMO) systems, where the low-resolution analog-to-digital converters(ADCs) are assumed to equip at the base station(BS), is investigated in this paper. We assume that only imperfect channel station information is known at the BS. Then a new MMSE receiver is designed by taking not only the Gaussian noise, but also the channel estimation error and quantizer noise into account. By using the Stieltjes transform of random matrix, we further derive a tight asymptotic equivalent for the uplink achievable rate with proposed MMSE receiver. We present a detailed analysis for the number of BS antennas through the expression of the achievable rates and validate the results using numerical simulations. It is also shown that we can compensate the performance loss due to the low-resolution quantization by increasing the number of antennas at the BS.

关键词： massive MIMO low-resolution quantization MMSE receiver

Studies and advances on joint source-channel encoding/decoding techniques in flow media communications

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Science china(Information Sciences) 2010年第1期53卷 1-17页

作者： TU GuoFang1, LIU JianJun1, ZHANG Can1,2, GAO ShaoShuai3.& LI ShiDong4 1School of Information Science and Engineering, Graduate University of Chinese academy of Sciences, beijing 100049, china 2{3. key laboratory of Information Security, Graduate University of Chinese academy of Sciences, beijing 100049, china 3.ational Institute of Standards and technology, Gaithersburg, MD 20899, USA, 4Department of Mathematics, San Francisco {3. University, San Francisco, CA 9413., USA 1. School of Information Science and Engineering Graduate University of Chinese Academy of Sciences Beijing 100049 China2. State Key Laboratory of Information Security Graduate University of Chinese Academy of Sciences Beijing 100049 China3. National Institute of Standards and Technology Gaithersburg MD 20899 USA4. Department of Mathematics San Francisco State University San Francisco CA 94132 USA

Joint source-channel coding/decoding (JSCC/JSCD) techniques in flow media communications have become a state-of-the-art and one of the challenging research subjects in the spatial communication area. They have great application prospective and deep impact in various manned space flights, satellite missions, mobile radio communications and deep-space explorations. In the last few years, there have been influential achievements in JSCC/JSCD studies. This paper aims at an introduction to the basic principles of joint source-channel optimal design. A general summarization and classification for various existing JSCC/JSCD methods is addressed. Also presented is a JSCD scheme based on variable-length coding, capable of providing reliable resolutions for flow media data transmission in spatial communications.

关键词： joint source-channel coding/decoding rate allocation variable-length coding/decoding iterative decoding

Deformation-induced α_2/γ Interfaces in a Hot-deformed Ti-45Al-10Nb Alloy

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Journal of Materials Science & technology 1998年第2期14卷 132-138页

作者： Jinguo WANG Lichun ZHANG and Guoliang CHEN (state key Lab. for Advanced Metals and Materials, University of Science and technology {3., {3. 100083. china )Henqiang YE(Lab. of Atomic Imaging of Solids, Institute of Metal Research, Chinese academy state key Lab. for Advanced Metals and Materials University of Science and Technology Beijing Beijing 100083 China Lab. of Atomic Imaging of Solids Institute of Metal Research Chinese Academy of Sciences Shenyang 110015 China

The structure change of α2/γ interface in a Ti-45Al-10Nb alloy induced by hot deformation was investigated by conventional and high-resolution transmission eIectron microscopy. Two types of hot deformation induced special α2/γ intedeces, coherent intedeces with high density of ledges and semi-coherent α2/γ intedeces were found to be due to the absorption of mobile dislocations into the α2/γ inteface. For the misoriented semi-coherent α2/γ interfaces, the densities of dislocation ledges increase with the misoriented angle between (111)γ and (0001)α2 planes, and 1/3.111] Frank partial dislocations were involved in the dislocation ledges. Formation mechanism of these deformation-induced α2/γ interfaces was discussed to be related to the role of α2/γ interface5 adjusting the deformation as a dislocation sink absorbing the slipping dislocations in the γ phase

关键词： Al Ti Interfaces in a Hot-deformed Ti-45Al-10Nb Alloy Deformation-induced