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Fairness-oriented physical layer network coding in cooperative multiple access channels due to MRC and SIC

The Journal of China Universities of Posts and Telecommunications 2012年第6期19卷 45-51页

作者： CHENG Yu-lun YANG Long-xiang Jiangsu Key Laboratory of Wireless Communications Nanjing University of Posts and Telecommunications Key Laboratory of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications

This paper investigates the impacts of network coding （NC） on user fairness from the network perspective in multiple access channels. Firstly, simultaneous outage is exploited as the metric to evaluate user fairness. To optimize it, a fairness-oriented physical layer NC scheme is proposed, in which users＇ signals are superimposed in specific calculated proportion at relay and then decoded by maximal ratio combination （MRC） and serial interference cancellation （SIC） at destination. Furthermore, the influence of power allocation coefficient error on simultaneous outage is also analyzed to reveal its correlation with user fairness. Simulation results indicate that the proposed scheme can supply approximately equal performance promotion for each cooperation-participated user and outperform those without fairness consideration in terms of the employed metric.

关键词： cooperative system user fairness simultaneous outage MRC SIC

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Impact of Maximum Transmit Power Limit on the First-Order and Second-Order Performance of Cognitive Opportunistic Relaying

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China communications 2015年第5期12卷 75-85页

作者： JIA Xiangdong DENG Pengfei ZHOU Ming YANG Longxiang ZHU Hongbo College of Computer Science and Engineering Northwest Normal University Wireless Communication Key Lab of Jiangsu Province Nanjing University of Posts and Telecommunications Key Lab of Broadband wireless Communication and Sensor Network Technique of Ministry of Education Nanjing University of Posts and Telecommunications

Abstract： This paper focuses on the first-or- der and second-order performance of dual-hop underlay cognitive radio systems with oppor- tunistic relaying （UCR-OR） over indepen- dent and non-identically distributed （***.d） Rayleigh fading channels. For the UCR-OR systems, the tolerable maximum interference power （TMIP） Q at primary users （PUs） and the allowable maximum transmission power limit （AMTP） P at secondary users （SUs） are considered, simultaneously. We first obtain the closed-form solutions to the first-order performance such as outage probability, ave- rage symbol error ratio （SER）, and ergodic capacity （EC）. Secondly, we investigate the second-order statistical performance, i.e., ave- rage outage rate （AOR） and average outage duration （AOD）. With the consideration that in practice implementation the receiver perfor- mance is primarily influenced by the signal- to-noise ratio （SNR）（not the signal envelope）, the second-order statistical performance is investigated based on the equivalent instan- taneous end-to-end SNR. Finally, we present the detailed performance comparison analysis of UCR-OR systems by defining a random variable ,μ=Pmax/Q. The results show that the effect of μ on the first-order and second-or- der performances is different greatly. For the first-order performance, the perlbrmance gap is negligible when the value of// is relatively large. However, for the second-order one, the gap is distinct.

关键词： cognitive radio opportunistic relaying outage probability average outage rate average outage duration

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Time-Efficient Power Allocation Scheme for Two-Way Multi-relay Cognitive Radio networks

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Chinese Journal of Electronics 2016年第2期25卷 357-363页

作者： ZHOU Zhikang ZHU Qi The Key Wireless Lab of Jiangsu Province School of Telecommunication and Information EngineeringNanjing University of Posts and Telecommunications Key Lab on Wideband Wireless Communications and Sensor Network Technology of Ministry of Education

Cooperative relaying has been emerging as a key technology in Cognitive radio(CR) networks. A two-way Amplify-and-forward(AF) based multi-relay CR network is considered, where a primary user coexists with a pair of secondary users and multiple relays. A Timeefficient sub-optimal power allocation scheme(TESOPA)based on Cauchy-Schwarz inequality is provided to maximize the total end-to-end transmission rate of the secondary system. TESOPA is proposed under maximal transmission power constraints, while ensuring the quality of service of the primary user during the whole communication process. The computational complexity is sharply decreased by using the Cauchy-Schwarz inequality. Simulation results show that the proposed TESOPA scheme performs very close to the near-optimal Interior point method based power allocation(IPMPA), especially in interference dominant networks where interference constraints play a key role in determining power allocation results instead of maximal transmission power constraints.

关键词： Power allocation Relay network Cognitive radio Amplify-and-forward Two-way communication

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Multidimensional reconciliation protocol for continuous-variable quantum key agreement with polar coding

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Science China(Physics,Mechanics & Astronomy) 2018年第9期61卷 99-102页

作者： ShengMei Zhao ZhiGang Shen Hong Xiao Le Wang Institute of Signal Processing Transmission Nanjing University of Posts and Telecommunications Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education

Continuous-variable quantum key distribution（CVQKD）[1-7]allows two remote parties（Alice and Bob）to share a secret key,even in the presence of an eavesdropper（Eve）with unlimited computational power[8-17].While,a highly efficient reconciliation protocol[18-21]is crucial in a CVQKDsystem, which can not only extract the errorless secret keys, but also provide a promising way to achieve a long distance CVQKD at a low signal-to-noise ratio （SNR）.

关键词：和解协议连续变量钥匙多维编码 SNR 长距离

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A Multi-dimensional Index Structure Based on Improved VA-file and CAN in the Cloud

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International Journal of Automation and computing 2014年第1期11卷 109-117页

作者： Chun-Ling Cheng Chun-Ju Sun Xiao-Long Xu Deng-Yin Zhang College of Computer Nanjing University of Posts and Telecommunications Jiangsu High Technology Research Key Laboratory for Wireless Sensor Networks Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and TelecommunicationsMinistry of Education Jiangsu Province

Currently,the cloud computing systems use simple key-value data processing,which cannot support similarity search efectively due to lack of efcient index structures,and with the increase of dimensionality,the existing tree-like index structures could lead to the problem of"the curse of dimensionality".In this paper,a novel VF-CAN indexing scheme is ***-CAN integrates content addressable network(CAN)based routing protocol and the improved vector approximation fle(VA-fle) *** are two index levels in this scheme:global index and local *** local index VAK-fle is built for the data in each storage ***-fle is thek-means clustering result of VA-fle approximation vectors according to their degree of *** cluster forms a separate local index fle and each fle stores the approximate vectors that are contained in the *** vector of each cluster center is stored in the cluster center information fle of corresponding storage *** the global index,storage nodes are organized into an overlay network CAN,and in order to reduce the cost of calculation,only clustering information of local index is issued to the entire overlay network through the CAN *** experimental results show that VF-CAN reduces the index storage space and improves query performance efectively.

关键词： Cloud computing index similarity search clustering vector approximation fle(VA-fle) content addressable network(CAN)

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Collusion detector based on G-N algorithm for trust model

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Journal of Systems Engineering and Electronics 2016年第4期27卷 926-935页

作者： Lin Zhang Na Yin Jingwen Liu Ruchuan Wang College of Computer Nanjing University of Posts and TelecommunicationsNanjing 210003China Jiangsu High Technology Research Key Laboratory for Wireless Sensor Networks Nanjing 210003China Key Lab of Broadband Wireless Communication and Sensor Network Technology Nangjing University of Posts and TelecommunicationsNangjing 210003China

In the open network environment, malicious attacks to the trust model have become increasingly serious. Compared with single node attacks, collusion attacks do more harm to the trust model. To solve this problem, a collusion detector based on the GN algorithm for the trust evaluation model is proposed in the open Internet environment. By analyzing the behavioral characteristics of collusion groups, the concept of flatting is defined and the G-N community mining algorithm is used to divide suspicious communities. On this basis, a collusion community detector method is proposed based on the breaking strength of suspicious communities. Simulation results show that the model has high recognition accuracy in identifying collusion nodes, so as to effectively defend against malicious attacks of collusion nodes.

关键词： trust model collusion detector G-N algorithm

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Green cloud task-scheduling algorithm based on improved BPSO

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Journal of Information and Computational Science 2014年第12期11卷 4301-4308页

作者： Ouyang, Zhiyou Wang, Kun Xu, Lili Key Lab. of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing University of Posts and Telecommunications Nanjing China

Cloud computing is experiencing a rapid development since a large amount of data need to be addressed. How to carry on the reasonable task scheduling plays a vital role in the operating efficiency of cloud computing. This paper proposes a Green Cloud Task-scheduling Algorithm (GCTA) based on the improved Binary Particle Swarm Optimization (BPSO). This work avoids matrix operations by using a pipeline number for virtual machines and redefining the position and velocity of particle. Simulation results show that the proposed GCTA has less execution time, and reduces resource consumption accordingly. © 2014 Binary Information Press

关键词： Cloud computing

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The research on joint distributed source coding and network coding for wireless multicast network

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Journal of Computational Information Systems 2013年第3期9卷 1147-1156页

作者： Liu, Ying Yang, Zhen Mei, Zhonghui Kong, Yuanyuan Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing University of Posts and Telecommunications Nanjing 210003 China

This paper considers the problem of transmitting correlated information from multiple sources to multiple receivers, where every receiver seeks to recover all of the original sources. In order to improve the efficiency of network transmission, we combine interflow network coding and distributed source coding using syndromes (DISCUS). Furthermore, for wireless multicast multi-hop network, we propose an adaptive transmission algorithm with target of minimum energy consumption based on the above practical joint scheme. The simulation results verify the validation of theoretical results in the paper. Copyright © 2013 Binary Information Press.

关键词： network coding

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The method of gaze tracking based on iris detection

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International Journal of Information and communication Technology 2013年第3-4期5卷 234-242页

作者： Zhang, Deng-Yin Wang, Zhou-Yang Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Ministry of Education Nanjing 210003 China

This paper presents a new method of gaze tracking based on iris detection for images of human eyes captured by ordinary PC camera. In the basis of traditional iris detection, this paper improves the circle detection based on Hough transform by self-adopted angle step and in order to overcome the impact of light spot and noise, and presents the algorithm of interference-points elimination. The position user focus on screen is detected by comparing to the conference position after accurately calculating the centre pixel of pupil iris area. The proposed method is significant to the optimisation of network services and applications by apperceiving user experience (UE) through analysis sight movement sample of network user. Experimental results demonstrate the feasibility, the correct rate is 92%, 86% in 6×4, 8×6 screen block dividing respectively under normal circumstances. © 2013 Inderscience Enterprises Ltd.

关键词： Eye tracking

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A resilient trust management scheme for defending against reputation time-varying attacks based on BETA distribution

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Science China(Information Sciences) 2017年第4期60卷 60-70页

作者： Weidong FANG Wuxiong ZHANG Yang YANG Yang LIU Wei CHEN Key Laboratory of Wireless Sensor Network & Communication Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai Research Center for Wireless Communication School of Computer Science and Technology China University of Mining and Technology

Compared with the encryption and the authentication which can prevent the external attacks,the trust management schemes are the better approaches for defending against the internal attacks in wireless sensor network(WSN). The reputation time-varying(RTV) attacks are internal attacks. In the reputation timevarying attacks, the reputation value of nodes is manipulated to adjust dynamically by the compromised nodes or malicious attackers. Hence, these attacks have greater covert and invasive. In this paper, we propose a Timewindow-based Resilient Trust Management Scheme(TRTMS) to defend against the reputation time-varying attacks in wireless sensor network. In this scheme, based on BETA distribution, the behaviors of compromised nodes are analyzed for a period of time, and then the difference judgment and the trend analysis are utilized to identify the abnormality of nodes’ reputation value, meanwhile, the control factor Fc and the time window are introduced to verify and remove the compromised modes from the suspected malicious nodes, which refer to those nodes’ reputation value changes are caused by the wireless channel changes. The result of simulation shows that our proposed scheme can defend reputation time-varying attacks effectively and it is convenient to implement.

关键词： wireless sensor network(WSN) reputation time-varying attack trust value trust management time window

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