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International Conference on wireless communications and Signal Processing (WCSP)

作者： Lei Wang Lulu Gao Aiqing Zhang Mingkai Chen National Mobile Communications Research Laboratory Southeast University Nanjing China NUPT Key Lab of Broadband Wireless Communication and Sensor Network Technology China

ISBN: (纸本)9781467376884

Device-to-device (D2D) communication technology can significantly improve energy efficiency and offload base station traffic. It has become a new research focus in next generation mobile communications. In this paper, a file-sharing mechanism based on social networks is proposed for the D2D communication system underlaying cellular networks aiming at improving the users' quality of experience (QoE). In the proposed mechanism, all users are divided into several groups according to the documentation requirements. Then the D2D communication links are built within each group by fully considering the social relationships and trust degrees of users. The target files give priority to be shared through the D2D mode. Theoretical analysis and extensive simulation results show clearly that the social relationships can affect the whole wireless networks significantly. Selecting a user with the largest social degree as a central user can greatly reduce the transmission delay, relieve the heavy burden of base stations and then optimize the overall performance of cellular communication systems.

关键词： Base stations Social network services Delays wireless communication Mobile communication Quality of service

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The Dynamic Index Design of network Management Data on HBase

The Dynamic Index Design of Network Management Data on HBase

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2015 International Conference on Advanced Management Science and Information Engineering(AMSIE 2015)

作者： J.D.Yang C.S.Ren W.Mao D.Y.Zhang Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and TelecommunicationMinistry of Education

Aimed at the problems that data access delay and static index structure cannot meet the demand of frequent index update in the massive network management data,a dynamic index mechanism based on HBase and a special index table is designed in this *** key value of the table is comprised of key value and indexed column which come from original data,thus enforcing the map of the indexed column with the original *** address the problems in frequently adding and deleting data,an index update algorithm is established in which only changed data is *** results show that the index structure will be adjusted as the data is adding and deleting,rustling in the optimal search *** query efficiency based on the improved method raises 4.98 times in 100 thousand rows and 55.66 times in 1 million *** more the number of the rows increases,the more search efficiency obviously improves.

关键词： network management data HBase index

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New Evaluation Model on Web Site Credibility

New Evaluation Model on Web Site Credibility

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2015 International Conference on Computer Information Systems and Industrial Applications(CISIA2015)

作者： Y.Y.Ma F.Chen Z.X.Sun Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing University of Posts and Telecommunications

ISBN: (纸本)9781510805750

In view of the existing web site credibility evaluation models failing to comprehensively consider the multiple attributes of trust,after learning the D- S evidence theory and fuzzy theory,a new web site credibility evaluation model is put forward in which the trust value is divided into historical trust value and the current trust *** study shows that the model can track the change of user preferences in real-time as well as can meet the dynamic nature of universal environment,so the trust assessment is more reasonable and accurate.

关键词： evaluation model d-s evidence theor fuzzy theory

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A RGB-D Face Recognition Approach without Confronting the Camera

A RGB-D Face Recognition Approach without Confronting the Ca...

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2015 IEEE International Conference on Computer and communications(ICCC 2015)

作者： Wei Zhou Jian-xin Chen Lei Wang Key Lab of Broadband Wireless Communication and Sensor Network Technology (Nanjing University of Posts and Telecommunications) Ministry of Education

Face recognition research mainly focuses on traditional 2D color images, which is extremely susceptible to be affected by external factors such as various viewpoints and has limited recognition accuracy. In order to achieve improved recognition performance, as well as the 3D face holds more abundant information than 2D, we present a 3D human face recognition algorithm using the Microsoft's Kinect. The proposed approach integrates the depth data with the RGB data to generate 3D face raw data and then extracts feature points, identifies the target via a two-level cascade classifier. Also, we build a 3D-face database including 16 individuals captured exclusively using Kinect. The experimental results indicate that the introduced algorithm can not only achieve better recognition accuracy in comparison to existing 2D and 3D face recognition algorithms when the probe face is exactly in front of Kinect sensor, but also can increase 9.3% of recognition accuracy compared to the PCA-3D algorithm when it is not confronting the camera.

关键词： 3D face recognition Kinect RGB-D images XML file classifier

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Performance analysis of two-hop-relay cellular systems with queueing capability

Performance analysis of two-hop-relay cellular systems with ...

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2015 International Conference on Information and communications Technologies, ICT 2015

作者： Lu, Weifeng Gu, Mengmeng Yang, Luxi College of Computer Nanjing University of Posts and Telecommunications Nanjing210023 China School of Information Science and Engineering SouthEast University Nanjing210096 China Jiangsu High Technology Research Key Laboratory for Wireless Sensor Networks Nanjing Jiangsu210023 China Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Ministry of Education Jiangsu Province Nanjing Jiangsu210023 China

ISBN: (纸本)9781849199940

In this paper, we present a two-hop-relay WCDMA cellular system with queueing capability, where a call can wait in the incoming buffer at the congested Base Transceiver Station (BTS) if no channel is immediately available, so as to reduce the call blocking rate. We develop an analytic model based on Multidimensional Markov chains. Then based on this model, we can obtain the average transmission rate and the queuing delay performance of the system respectively. Finally, through numerical calculation, we analyze the impact of the various parameters on the performance of the two-hop-relay WCDMA cellular system with queueing capability.

关键词： Queueing theory

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Bandwidth allocation scheme for multimedia communications over cognitive radio networks

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Journal of Computational Information Systems 2015年第13期11卷 4931-4940页

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

This paper proposes a scheme based on Game Theory to resolve the problem that how to allocate the bandwidth sharing among one primary user and multiple secondary users in multimedia communications, over cognitive radio networks. In this scheme, we not only consider the impact of secondary users on primary user, but also propose a penalty factor and positive factor when constructing primary user utility function. Primary user can increase penalties on secondary users by adjusting penalty factor. This will reduce the impact on himself. The propose of positive factor fully reflects the primary users' wishes of allocating bandwidth to the second users. The higher enthusiasm of the primary user, the more bandwidth will be assigned to the secondary user. The construct of secondary users' utility function gives full consideration on the video service characteristics that different user required different bandwidth to transmit because of their different video content. In view of the network status, we propose a network congestion model. The correctness of this algorithm has been tested by theory and the simulation result shows a better performance compared with traditional method. ©, 2015, Journal of Computational Information Systems. All right reserved.

关键词： Game theory

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Effect of outdated CSI on buffer-aided underlay cognitive relay networks

Effect of outdated CSI on buffer-aided underlay cognitive re...

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International Conference on wireless communications and Signal Processing (WCSP)

作者： Xuanxuan Tang Yueming Cai Wendong Yang Weiwei Yang Tao Zhang Hualiang Chen College of Communications Engineering PLA University of Science and Technology Nanjing China Key Lab of Broadband Wireless Communication and Sensor Network Technology (Nanjing University of Post and Telecommunications) Ministry of Education

ISBN: (纸本)9781467376884

This work studies the impact of outdated channel state information (CSI) on decode-and-forward (DF) buffer-aided underlay cognitive relay networks (CRNs), with the following three key constraints considered: the maximum transmit power of the secondary network (P), the peak interference power at the primary user (I) and the interference power at the secondary network caused by the primary network (P PS ). This makes it much more involved to handle with than existing works. By modeling the transitions of the buffer states with Markov chain theory, a closed-form expression of the outage probability for the system with finite-size buffers is derived, which depicts the impact of outdated CSI on the outage performance of buffer-aided CRNs. In addition, it is also demonstrated that the performance of the secondary network is improved with the increase of the interference threshold that the primary users can tolerate, but decreases with the increase of the transmit power of the primary network, which is useful in the design of buffer-aided CRNs. Monte-Carlo simulations are given to verify the validity of the theoretical analysis.

关键词： Interference Signal to noise ratio Delays Relay networks (telecommunications) Markov processes Fading

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Interference suppression algorithms for D2D communication underlaying cellular networks

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Journal of Computational Information Systems 2015年第18期11卷 6705-6717页

作者： Huan, Cheng Liu, Chen Fu, Youhua The Key Lab. of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing University of Posts and Telecommunications Nanjing China National Mobile Communications Research Laboratory Southeast University Nanjing China

In this paper, we investigate the interference scenario where Device-to-Device (D2D) users and the cellular user share the same spectrum resource, and propose two novel interference suppression algorithms for D2D communication. One of the two proposed algorithms is the step-by-step interference suppression algorithm called SISA, and the other one is the joint interference suppression algorithm called JISA. The SISA mainly deals with the cellular interference to the D2D receiver, while the JISA copes with not only the cellular interference but also the noise at the D2D receiver. Both algorithms are designed from the perspective of precoding and decoding. Based on this, we first formulate the interference suppression problem for D2D communication as an optimization problem to maximize the signal-to- interference- plus-noise ratio (SINR) of the D2D receiver, and regard the precoding vector of the D2D transmitter and the decoding vector of the D2D receiver as the optimized variables. Second, we in turn propose the SISA and JISA to solve the optimization problem. Finally, we derive out respective closed-form expressions for optimize variables according to the SISA and JISA. Numerical results show that the two proposed algorithms both enable D2D to achieve significant performance gains over that using the existing schemes in terms of SINR and bit-error rate (BER). © 2015 by Binary Information Press.

关键词： Bit error rate

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Energy-efficient resource allocation based on proportional fairness in OFDM multi-user systems

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Journal of Information and Computational Science 2015年第12期12卷 4705-4713页

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

This paper considers the problem of resource assignment with proportional fairness for multi-user OFDM relaying systems in single cell. An energy-efficient strategy is proposed including relay selection, subcarrier assignment and power allocation subjecting to individual power constraint. The optimal purpose is to maximize the sum of the logarithm per user rate per power. The optimization problem is decomposed into some sub-problems, since the joint optimization problem leads to a mixed-fraction time-complete problem. First, Dinkelbach's method is employed for transforming the fractional programming to integral expression. Then, continuous relaxation is used to solve the dual problem by bisection method and Lagrangian dual decomposition method. Simulation results show that the proposed algorithm has a good trade-off between the throughput and fairness compared with other schemes. Copyright © 2015 Binary Information Press.

关键词： Energy efficiency

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R-PMD: robust passive motion detection using PHY information with MIMO

R-PMD: robust passive motion detection using PHY information...

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IEEE International Conference on Performance, Computing and communications (IPCCC)

作者： Hai Zhu Fu Xiao Lijuan Sun xiaohui Xie Panlong Yang Ruchuan Wang College of Computer Nanjing University of Posts and Telecommunications China Key Lab of Broadband Wireless Communication and Sensor Network Technology of Ministry of Education China College of Communications Engineering PLA University of Science and Technology China

Robust Device-free passive (Dfp) detection is an essential primitive for a broad range of applications such as intrusion detection and smart space. Most recent works focus on finer-grained Channel State Information (CSI), instead of the variable Received Signal Strength (RSS). However, existing solutions have some limitations, being feasible only in the line of sight (LOS) or for more than one targeted entities. Moreover, space diversity supported by the MIMO systems hasn't been fully investigated. Motivated by this observation, we propose a novel scheme for Robust Passive Motion Detection (R-PMD). In our scheme, the variance of CSI amplitude feature is extracted as a new metric and the earth mover's distance (EMD) is utilized to determine the detection results. Besides, CSIs across multiantennas are further exploited to improve the detection precision and robustness. We prototype R-PMD on commercial WiFi devices and evaluate it in a typical indoor scenario. Experiment results show R-PMD can achieve great performance in terms of sensitivity and robustness.

关键词： Feature extraction MIMO Robustness wireless communication Legged locomotion Receiving antennas Measurement

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