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Outage performance analysis in cognitive wireless relay networks

Research Journal of Applied Sciences, Engineering and technology 2012年第20期4卷 3958-3964页

作者： Yue, Wenjing Chen, Zhi Wang, Anyi Hu, Luoquan Wang, Lei Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunication Nanjng China

The analysis the outage performance of suggested Cognitive Wireless Relay network (CWRN) which consists of a source, a destination and M cognitive relay nodes and M primary user nodes. In this study, we mainly study that the cognitive relay nodes impact on the outage performance of proposed CWRN over Rayleigh channels under both the peak and average interference power constraints. Firstly, considering a scenario with a single cognitive relay node, the optimal power control policies of the cognitive relay nodes are derived in order to achieve the minimum system outage probability under different interference power constraints. Then, to further improve outage performance, a scenario with multi-relay is also studied. Finally, the numerical simulations are presented. Numerical results show that substantial performance improves with the increase of the number of cognitive relay nodes and the power control policy under the average interference power constraint is more effective than that under the peak interference power constraint. © Maxwell Scientific Organization, 2012.

关键词： Cognitive radio

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NLOS Error Mitigation in Mobile Location Based on Modified Extended Kalman Filter

NLOS Error Mitigation in Mobile Location Based on Modified E...

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IEEE Wireless communications and networking Conference (WCNC)

作者： Zhou, Xin Jin, A-Long Meng, Qingmin Key Lab. of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Southeast University Nanjing China National Mobile Communications Research Lab. Southeast University Nanjing China Nanjing University of Posts and Telecommunications Nanjing 210003 China

ISBN: (纸本)9781467304375;9781467304368

Geolocation and tracking of mobile objects is an important issue in wireless communication networks. Various methods have been devised and implemented to deal with such problems whose performance is particularly limited in non-line-of-sight propagation conditions. In this paper, we take advantage of the extended Kalman filter with some extensions, modifications and improvement of previous work to reduce the NLOS error in the location measurement. One of the key contributions of this paper is to present the methods that discriminate the NLOS measurements from the LOS measurements based on the standard deviation and K-means clustering and reconstruct the LOS measurements out of the NLOS measurements by polynomial fit in order to mitigate the NLOS error. Simulation results confirm the effectiveness and accuracy of our approach in comparison with the conventional EKF algorithm. Moreover, we do not model the distribution of the NLOS error due to its intractability.

关键词： Non-Line-of-Sight Extended Kalman filter K-means clustering LOS reconstruction polynomial fit

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Delay constraint adaptive routing based on seed spray in opportunistic networks

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Journal of Computational Information Systems 2012年第12期8卷 5137-5148页

作者： Xu, Jia Wang, Ruchuan Sun, Lijuan College of Computer Nanjing University of Posts and Telecommunications Nanjing 210003 China Jiangsu High Technology Research Key Laboratory for Wireless Sensor Networks Nanjing 210003 China Key Lab. of Broadband Wireless Communication and Sensor Network Technol. Min. of Edu. Jiangsu Prov. Nanjing University of Posts and Telecommunications Nanjing 210003 China Key Laboratory for Computer Network and Information Integration Ministry of Education Southeast University Nanjing 211189 China State Key Lab. for Novel Software Technology Nanjing University Nanjing 210093 China

Opportunistic networks are sparse wireless networks which have no complete path from the source to the destination most of the time. Many applications require the support of delay constrained routing mechanism which can provide acceptable and resilient services in the challenged environments. We proposed Adaptive Seed Spray (ASS) to achieve the delay constraint with low cost in dynamic opportunistic networks. ASS will estimate the routing cost in source node, and use a small number of seed nodes to spray message copies in order to reduce redundant copies. Furthermore, ASS will make spray decisions in relay nodes which have the latest information of the networking conditions. Simulation results have shown that ASS has prominent superiority in routing cost and adaptability, and it is an efficient delay-bounded multi-copy routing protocol for opportunistic networks especially for dynamic conditions. © 2012 Binary Information Press.

关键词： Cost benefit analysis

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QoS-based data aggregation technology in wireless sensor networks

QoS-based data aggregation technology in wireless sensor net...

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2011 WASE Global Conference on Science Engineering, GCSE 2011

作者： Chen, Zhengyu Yang, Geng Li, Guohua Xu, Jian Key Lab. of Broadband Wireless Communication and Sensor Network Technology Ministry of Education College of Computer Science and Technology Nanjing University of Post and Telecommunications Nanjing 210046 China School of Information Technology Jinling Institute of Technology Nanjing 211169 China

ISBN: (纸本)9783037852903

The main goal of data-aggregation algorithms in wireless sensor networks (WSNs) is to gather and aggregate data in an energy efficient manner so that network lifetime is enhanced. In this article, we focus on QoS-based data-aggregation problems in WSNs. Firstly, we provide a definition of the different QoS parameters for data aggregation, such as energy efficiency, network lifetime, data latency and data quality. Then, we compare the different algorithms on each QoS parameter, describe the main features of each algorithm, and highlight the trade-offs between each parameter. Finally, we conclude with possible future research directions on QoS-based data aggregation in WSNs.

关键词： Wireless sensor networks

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A code dissemination protocol of low energy consumption

A code dissemination protocol of low energy consumption

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2012 International Conference on Web Information Systems and Mining, WISM 2012

作者： Wang, Haiyong Yang, Geng Xu, Jian Chen, Zhengyu Yang, Zhen Key Lab of Broadband Wireless Communication Sensor Network Technology of Ministry of Education Nanjing University of Post and Telecommunications Nanjing 210003 China College of Internet of Things Nanjing University of Posts and Telecommunications Nanjing 210003 China

ISBN: (纸本)9783642334689

Dissemination and update of the code image plays an important role in application of the Internet of Things (IoT). As a part of the IoT, Wireless sensor networks should provide the code dissemination. The commonly used method for periodical broadcasting metadata packages to determine whether code dissemination is needed consumes excessive energy. So a low energy consumption code dissemination protocol is proposed for this issue. That is whether code dissemination is necessary can be determined when the sensor node is under normal communication. The simulation result shows that the proposal in this article has reduced the energy consumption when the network needs code dissemination. © Springer-Verlag Berlin Heidelberg 2012.

关键词： Metadata

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A novel clustering mechanism based on image-oriented correlation coefficient for wireless multimedia sensor networks

A novel clustering mechanism based on image-oriented correla...

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2012 International Conference on Web Information Systems and Mining, WISM 2012

作者： Wu, Rong Wang, Ruchuan Sha, Chao Qian, Liyang College of Computer Nanjing University of Posts and Telecommunications Nanjing 210003 China Jiangsu High Technology Research Key Laboratory for Wireless Sensor Networks Nanjing 210003 China Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing University of Posts and Telecommunications Nanjing 210003 China

ISBN: (纸本)9783642334689

Wireless multimedia sensor networks consist of unattended multimedia nodes with limited storage, energy and computation and communication capabilities. And energy is the most crucial resource for nodes. Clustering technique has been proven to be an effective approach for datagathering in wireless multimedia sensor networks. Therefore, this paper presents a novel clustering mechanism based on image-oriented correlation coefficient to reduce redundancy transmission so as to conserve network energy. And the aim is achieved through taking advantage of the correlation coefficient of captured images and RSSI value of nodes to avoid excessive computation and transmission. Moreover, a new cluster header election method is also presented to make the network's load balance on energy. The simulation results show that the correlation coefficient threshold greatly affects the number and average size of clusters. And compared with another clustering algorithm based on overlapping FoVs, our clustering mechanism is more effective in prolonging network lifetime. © Springer-Verlag Berlin Heidelberg 2012.

关键词： Clustering algorithms

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Improved Quantum Genetic Algorithm for Competitive Spectrum Sharing in Cognitive Radios

Improved Quantum Genetic Algorithm for Competitive Spectrum ...

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International Conference in Electrics, communication and Automatic Control, ECAC 2011

作者： Li, Fei Zhu, Dongpo Tian, Feng Li, Haibo Institute of Signal Processing and Transmission Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing University of Posts and Telecommunications Nanjing China Department of Applied Physics and Electronics Umeå University Umeå Sweden

ISBN: (纸本)9781441988485

This chapter investigates a kind of whole new approach to spectrum sharing in cognitive radio (CR) system, quantum-inspired approach. First, we improved Quantum Genetic Algorithm (QGA) by adding quantum crossover operator to overcome the shortcomings of the original QGA, easily falling into a local extremum when used to optimize the continuous functions with many extrema. We then propose a novel spectrum sharing scheme in noncooperative game for CR system based on our improved QGA. We use QGA as competitive strategies and provide simulation results that confirm the proposed schemes have better convergence rate and higher sum capacity than genetic algorithm (GA)-based scheme, namely at most 1 bit/s/Hz increase in capacity. The results demonstrate the effectiveness and the applicability of QGA in spectrum sharing in CR system. © Springer Science+Business Media, LLC 2012.

关键词： Cognitive radio

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Information encryption based on virtual optical imaging system and Chen's chaos

Information encryption based on virtual optical imaging syst...

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2012 International Conference on Web Information Systems and Mining, WISM 2012

作者： Zhu, Wei Yang, Geng Xu, Jian Yang, Xiao-Ling College of Science Nanjing University of Posts and Telecommunications Nanjing 210003 Jiangsu China Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing University of Posts and Telecommunications Nanjing 210003 Jiangsu China

ISBN: (纸本)9783642334689

A new scheme of information encryption is presented in this paper, which employs Chen's chaos to construct the random mask of the virtual optical imaging system instead of randomly generated by computer. The generation of random mask, the procedures of encryption and decryption are described in detail. Numerical simulations prove that the constructed random mask is uniformly distributed and the encryption algorithm is effective. The experimental results also demonstrate that the proposed encryption algorithm has advantages of large key space and high key sensitivities. © Springer-Verlag Berlin Heidelberg 2012.

关键词： Imaging systems

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An Improved Comentropy-based Multi-objective Optimization Algorithm

An Improved Comentropy-based Multi-objective Optimization Al...

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第23届过程控制会议

作者： Kun Wang Linlin Wang Yan Liu Yuhua Zhang Huang Guo Yue Yu Key Lab of Broadband Wireless Communication and Sensor Network Technology (Nanjing University of Pos College of automation and electrical engineering Nanjing University of Technology Nanjing 210009 Key Lab of Broadband Wireless Communication and Sensor Network Technology (Nanjing University of Pos

To solve the increasing run-time complexity with the growth of population solutions in PESA, an evolutionary algorithm of multi-objective optimization, we present a comentropy- based PESA algorithm (C-PESA). With this algorithm, the gradual development and maturity of the solution sets can be observed with the continuous calculation of entropy values to determine whether to stop the optimization process or not, which reduces the run-time complexity to some extent. Simulation results show that the computational effort of C-PESA increases at a linear order with the increasing number of solutions, and the efficiency of evolutionary algorithm shows improvement.

关键词： PESA algorithm comentropy multi-objective optimization evolutionary algorithm Pareto-optimal run-time complexity

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Gossip-based indexing ring topology for 2-dimension spatial data in overlay networks

Gossip-based indexing ring topology for 2-dimension spatial ...

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2012 International Workshop on Information and Electronics Engineering, IWIEE 2012

作者： Zou, Z.Q. Wang, Y. Hu, B. Wang, R.C. College of Computer Nanjing University of Posts and Telecommunications Nanjing Jiangsu 210003 China Jiangsu High Technology Research Key Laboratory for Wireless Sensor Networks Nanjing Jiangsu 210003 China Key Lab. of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Jiangsu Province Nanjing Jiangsu 210003 China

Overlay networks are used widely in the Internet, such as retrieval and share of files, multimedia games and so on. However, in distributed system, the retrieval and share of 2-dimension spatial data still have some difficult problems and can not solve the complex retrieval of 2-dimension spatial data efficiently. This article presents a new indexing overlay networks, named 2D-Ring, which is the ring topology based on gossip for 2-dimension spatial data. The peers in our overlay networks exchange the information periodically and update each local view by constructing algorithm. 2-dimension spatial data is divided by quad-tree and mapped into control points, which are hashed into 2D-Ring by SHA-1 hash function. In such way, the problem of 2-dimension spatial data indexing is converted to the problem of searching peers in the 2D-Ring. A large of extensive experiments show that the time complexity of constructing algorithm of 2D-Ring can reach convergence logarithmically as a function of the network size and hold higher hit rate and lower query delay. © 2011 Published by Elsevier Ltd.

关键词： Overlay networks

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