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International Conference on Automatic Control and Artificial Intelligence (ACAI 2012)

作者： Ju-rong Shi Qi Zhu Jiangsu Key Lab of Wireless Communications Key Lab on Wideband Wireless Communications and Sensor Network Technology of Ministry of Education Nanjing University of Posts and Telecommunications 210003 China

In order to mitigate the interference between macrocell mobile stations (mMSs) and femtocells and allocate the spectrum efficiently, a graph coloring based clustering algorithm for channel allocation is proposed in this paper. Under the premise of guaranteeing the SINR requirements of mMSs, the algorithm determines the initial set of subchannels which can be used for each femtocell. Then according to the constructed interference graph of the femtocell networks, each femtocell mobile station(fMS) is allocated all the available spectrum resources dynamically. In this paper, we use an improved cluster algorithm to ensure the SINR of mMSs and maximize the femtocell throughput. Simulation results show that the proposed algorithm can reduce the outage probability of mMSs as well as improve the total throughput.

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A new algorithm of spectrum allocation based on the balance between supply and demand in cognitive radio networks

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Journal of networks 2012年第7期7卷 1017-1023页

作者： Ma, Liang Zhu, Qi Jiangsu Key Laboratory of Wireless Communications Nanjing University of Posts and Telecommunications Nanjing 210003 China Key Lab on Wideband Wireless Communications and Sensor Network Technology of Ministry of Education Nanjing University of Posts and Telecommunications Nanjing 210003 China

This paper investigates a new spectrum sharing algorithm based on price in cognitive radio networks. A supply and demand model between primary users and secondary users is established to decide the price of free spectrum leased by primary users. Considering the utility of primary users and the total bandwidth while deciding the price per bandwidth using supply and demand balance (the spectrum supplied by primary users is the same as which demanded by secondary users) and each secondary user competes with each other according to the price to share the available bandwidth allocated by primary users. At the same time, the battery capacity of secondary users and the reliance degree that how primary users trust secondary users in the spectrum sharing process are also considered,a new secondary utility and spectrum sharing algorithm are designed based on above factors. The existence and uniqueness of Nash equilibrium are proved from both theoretic and simulated aspects. The simulation results show that primary users could receive maximum revenues by allocating spectrum in equilibrium price, and the spectrum shared by secondary users is directly affected by the reliance degree and remaining battery capacity of secondary users. © 2012 ACADEMY PUBLISHER.

关键词： Game theory

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Joint Scheduling and Power Allocation in OFDMA network with Decode-and-Forward Relaying

Joint Scheduling and Power Allocation in OFDMA Network with ...

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2012 3rd International Conference on Information technology for Manufacturing Systems(ITMS 2012)

作者： Lv Linshu Zhu Qi The Key Wireless Lab of Jiangsu Province School of Telecommunication and Information Engineering Nanjing University of Posts and Telecommunications The Key Lab on Wideband Wireless Communications and Sensor Network Technology of Ministry of Education

This paper investigates the resource allocation of Orthogonal Frequency Division Multiplexing Access(OFDMA) cellular network with DF relaying in the downlink.A joint scheme of relay selection, subcarrier assignment and power allocation is proposed to maximize the system sum rate subject to individual power constraints and heterogeneous users' rate *** the original problem is a mixed integer programming(MIP), we transform it to a standard convex optimization by continuous relaxation and solve it via iterative water-filling(IWF) and subgradient methods in the dual *** the joint scheme, the upper bound is studied through an exhaustive bisection *** results show that the proposed scheme outperforms the traditional methods in terms of both system throughput and users' satisfactions.

关键词： Joint resource allocation DF relaying heterogeneous users OFDMA

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A calculation method for handoff rate based on angle mobility model

A calculation method for handoff rate based on angle mobilit...

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International Conference on Systems and Informatics (ICSAI)

作者： Zheng Shi Qi Zhu Jiangsu Key Laboratory of Wireless Communications Key Laboratory on Wideband Wireless Communications and Sensor Network Technology of Ministry of Education Nanjing University of Posts and Telecommunications Nanjing Jiangsu China

Mobility model is important for the performance analysis of wireless networks. The paper presents an angle mobility model. Based on the model, the characters of the direction angle for terminal mobility are analyzed and a calculation method for handoff rate is proposed. The theoretical closed-formula is derived for handoff rate in the condition that users' moving direction is unchanging in the fixed time interval T. It can be clearly demonstrated that the handoff rate is determined by users' distributed density, moving speed, and cell radius. However, previous techniques calculating handoff rate require knowledge of the distribution of the cell residence times which is difficult to measure. The formulas of handoff rate illustrate that the number of cell's users is dynamic equilibrium. The simulation results demonstrate the validity of the theoretical analysis for handoff rate.

关键词： Mobile communication Simulation wireless LAN wireless networks Analytical models Computational modeling Dynamic equilibrium

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Dynamic configuration of physical carrier sensing threshold and throughput analysis

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Journal of Computational Information Systems 2012年第11期8卷 4561-4568页

作者： Ran, Wenwen Zhu, Qi Jiangsu Key Laboratory of Wireless Communications Nanjing University of Posts and Telecommunications Nanjing 210003 China Key Lab. on Wideband Wireless Communications and Sensor Network Technology of Ministry of Education Nanjing University of Posts and Telecommunications Nanjing 210003 China

The choice of physical carrier sensing threshold affects the performance of the MAC layer protocol in multi-hop networks. This paper takes the effect of carrier sensing threshold on QoS into account, and develop an analytical model to dynamically achieve the carrier sensing threshold and analyse the impact on QoS. On the occasion of path loss only (a = 4), the paper proposes a method to get CST, which is to tradeoff the areas of hidden and exposed nodes, in other words, the numbers of both can reach compromise and the total number is least. In this way, we can get CST of every node that makes spatial reuse and throughput achieve balanced. It is found that the ratio of CST to the distance of sender and receiver has important effect on system throughput. At last, the paper compares the performance of the proposed method to that one of [1], and finds that this method improves the system throughput and spatial reuse. © 2012 Binary Information Press.

关键词： Packet loss

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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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Research on multi-sensor feature fusion based on improved CBPSO-SVM in WSN

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Journal of Computational Information Systems 2012年第2期8卷 763-770页

作者： Wu, Jianrong Sun, Yuxuan Bao, Bisai Liu, Haitao Key Lab. of Wireless Sensor Network and Communications Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai 200050 China

In pattern classification of wireless sensor network (WSN), multi-sensor feature fusion can improved the classification performance, but there are lots of irrelevant and redundant features which cause considerable computation even restrict the performance. To solve this problem, a wrapper feature selection approach combining CBPSO and SVM for multi-sensor feature fusion is proposed. Improved CBPSO algorithm is utilizing to select an optimum subset containing more effective features for classification, while SVM with k-fold cross-validation is used to evaluate the classification accuracy and efficiency of feature selection. According to the experimental results of actual seismic and acoustic data, the proposed approach can achieve high classification accuracy with fewer features. 1553-9105/Copyright © 2012 Binary Information Press.

关键词： wireless sensor networks

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Parking space detection based on information from images and magnetic sensors

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Advances in Information Sciences and Service Sciences 2012年第5期4卷 208-216页

作者： Zhu, Jian Cao, Hongbing Liu, Haitao Key Lab of Wireless Sensor Network and Communications Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai China Wuxi SensingNet Industrialization Research Institute Wuxi China

Parking space detection is a key technology in the parking lot management system. When performing parking space detection using magnetic sensors, there may be interference from the adjacent parking space, which will result in false detection. However there still will be false detection when only cameras are used to detect the parking spaces because the performance of the cameras is inclined to be affected by the environment. Considering that the magnetic sensors are only sensitive to ferromagnetic objects and insensitive to the environment effect and images often contain a wealth of information, we propose a parking space detection algorithm combining the information from magnetic sensors and images. The algorithm performs primitive detection using magnetic sensors. If the sensor reports that there is a vehicle nearby, the algorithm analyzes the image information of the parking space gathered by the camera, extracts the image features of the parking space and classifies the features to confirm whether the parking space is occupied. The experimental results show that our algorithm can make more precise decisions for parking space detection with much lower complexity and less computational efforts. Furthermore our algorithm can effectively reduce the burden of image or video processing of the system.

关键词： Cameras

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Analysis and improvement of affinity propagation based on Euclidean distance similarity

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Journal of Computational Information Systems 2012年第6期8卷 2293-2300页

作者： Deng, Sui Cao, Hongbing Pan, Qiang Shen, Jie Xing, Tao Liu, Haitao Key Lab. of Wireless Sensor Network and Communications Shanghai Institute of Microsystem and Information Technology CAS Shanghai 200050 China Wuxi SensingNet Industrialization Research Institute Wuxi 214135 China

Affinity propagation is an effective clustering algorithm which has been a hot point in recent years. In this paper, we analyze the similarity matrix based on Euclidean distance for AP algorithm and propose the genetic AP algorithm which finds appropriate assignments to the diagonal elements of similarity matrix before clustering. The simulation and actual test show that the genetic AP algorithm has great advantages over the original AP algorithm both in clustering quality and convergence time. © 2012 Binary Information Press.

关键词： Genetic algorithms

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A Quantum Genetic Algorithm for continuous Space optimization based on Search Space Partition

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International Journal of Advancements in Computing technology 2012年第4期4卷 73-83页

作者： Li, Junying Wu, Jianrong Liu, Haitao Key Lab of Wireless Sensor Network and Communications Shanghai Institute of Microsystem and Information Technology Chinese Academy of Science Shanghai 200050 China Wuxi SensingNet Industrialization Research Institute Wuxi 214135 China

In view of the slowness, the locality of convergence and the low accuracy of Simple Genetic Algorithm (SGA) in solving complex continuous space optimization problems, we introduce an improved genetic algorithm called Quantum Genetic Algorithm based Search Space Partition (SSPQGA). In this algorithm, the search space partition method is used to increase search accuracy and inhibit premature problem. The chromosomes are composed of quantum bits whose probability amplitudes comprise gene chains. The quantum chromosomes are evolved by quantum rotation gates, and mutated by quantum non-gates. Several typical examples are carried out and the results indicate that the novel algorithm possesses advantages such as less chance of being trapped into premature states, higher accuracy and higher stability. As a result, SSPQGA can be widely applied to many complex continuous space optimization problems which require higher accuracy.

关键词： Genetic algorithms

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