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International Conference on Acoustics, Speech, and Signal Processing (ICASSP)

作者： Xiaohuan Wu Wei-Ping Zhu Jun Yan Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Nanjing China Department of Electrical and Computer Engineering Concordia University Montreal Canada

ISBN: (纸本)9781479999897

This paper addresses the issue of direction-of-arrival (DOA) estimation with an objective to eliminate the off-grid effect of the sparsity-based methods and enlarge the maximum number of distinguishable signals in the subspace-based methods. We first reconstruct the covariance matrix of the array output in the Toeplitz structure and then employ the reconstructed covariance matrix together with root-MUSIC to estimate the DOAs. The proposed covariance matrix reconstruction approach (CMRA) can be used for uniform and sparse linear arrays. It can also estimate the DOAs of multiple signals that are larger than the number of sensors by taking advantage of the array geometry. In contrast to the sparsity-based methods, CMRA is formulated in the continuous angle space rather than the discretized one, and hence it is immune to the off-grid effect. Simulations are carried out to verify the effectiveness of our method.

关键词： Covariance matrices Direction-of-arrival estimation Estimation sensor arrays Minimization Eigenvalues and eigenfunctions Geometry

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Interactive Evolutionary Multi-Objective Optimization Algorithm Using Cone Dominance

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Journal of Harbin Institute of technology(New Series) 2015年第6期22卷 76-84页

作者： Dalaijargal Purevsuren Saif ur Rehman Gang Cui Jianmin Bao Nwe Nwe Htay Win School of Computer Science and Technology Harbin Institute of Technology Key Lab of Broadband Wireless Communication and Sensor Network Technology (Jiangsu Provincial Engineering Research Center of Telecommunications and Network Technology) Ministry of Education

As the number of objectives increases,the performance of the Pareto dominance-based Evolutionary Multi-objective Optimization( EMO) algorithms such as NSGA-II,SPEA2 severely deteriorates due to the drastic increase in the Pareto-incomparable solutions. We propose a sorting method which classifies these incomparable solutions into several ordered classes by using the decision maker's( DM) preference *** is accomplished by designing an interactive evolutionary algorithm and constructing convex cones. This method allows the DMs to drive the search process toward a preferred region of the Pareto optimal front. The performance of the proposed algorithm is assessed for two,three,and four-objective knapsack problems. The results demonstrate the algorithm ' s ability to converge to the most preferred point. The evaluation and comparison of the results indicate that the proposed approach gives better solutions than that of NSGA-II. In addition,the approach is more efficient compared to NSGA-II in terms of the number of generations required to reach the preferred point.

关键词： multi-objective optimization evolutionary optimization preference information pareto dominance cone dominance

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Secure and Efficient Signature Scheme Based on NTRU for Mobile Payment

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Journal of Physics: Conference Series 2017年第1期910卷

作者： Yunhao Xia Lirong You Zhe Sun Zhixin Sun Nanjing University of Posts and Telecommunications Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing P. R. China Zhongtian Technology Corporation Nantong P. R. China

Mobile payment becomes more and more popular, however the traditional public-key encryption algorithm has higher requirements for hardware which is not suitable for mobile terminals of limited computing resources. In addition, these public-key encryption algorithms do not have the ability of anti-quantum computing. This paper researches public-key encryption algorithm NTRU for quantum computation through analyzing the influence of parameter q and k on the probability of generating reasonable signature value. Two methods are proposed to improve the probability of generating reasonable signature value. Firstly, increase the value of parameter q. Secondly, add the authentication condition that meet the reasonable signature requirements during the signature phase. Experimental results show that the proposed signature scheme can realize the zero leakage of the private key information of the signature value, and increase the probability of generating the reasonable signature value. It also improve rate of the signature, and avoid the invalid signature propagation in the network, but the scheme for parameter selection has certain restrictions.

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A Normalization Model for Analyzing Multi-Tier Millimeter Wave Cellular networks

arXiv

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arXiv 2017年

作者： Xiong, Siqing Wang, Lijun Kwak, Kyung Sup Bai, Zhiquan Wang, Jiang Li, Qiang Han, Tao School of Electronic Information and Communications Huazhong University of Science and Technology Wuhan China School of Electronic Information Wuhan University Wuhan China Faculty of information science and technology Wenhua College Wuhan China Department of Information and Communication Inha university Incheon Korea Republic of School of Information Science and Engineering Shandong University Jinan China Shanghai Research Center for Wireless Communications Shanghai China Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai China Key lab of wireless sensor network and communication Chinese Academy of Sciences Shanghai China

—Based on the distinguishing features of multi-tier millimeter wave (mmWave) networks such as different transmit powers, different directivity gains from directional beamforming alignment and path loss laws for line-of-sight (LOS) and non-line-of-sight (NLOS) links, we introduce a normalization model to simplify the analysis of multi-tier mmWave cellular networks. The highlight of the model is that we convert a multi-tier mmWave cellular network into a single-tier mmWave network, where all the base stations (BSs) have the same normalized transmit power 1 and the densities of BSs scaled by LOS or NLOS scaling factors respectively follow piecewise constant function which has multiple demarcation points. On this basis, expressions for computing the coverage probability are obtained in general case with beamforming alignment errors and the special case with perfect beamforming alignment in the communication. According to corresponding numerical exploration, we conclude that the normalization model for multi-tier mmWave cellular networks fully meets requirements of network performance analysis, and it is simpler and clearer than the untransformed model. Besides, an unexpected but sensible finding is that there is an optimal beam width that maximizes coverage probability in the case with beamforming alignment errors. Copyright © 2017, The Authors. All rights reserved.

关键词： wireless networks

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A reliable data transmission protocol based on multipath routing for wireless sensor networks

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sensor Letters 2016年第9期14卷 923-927页

作者： Wang, Haiyong Yang, Geng Xu, Jian Gu, Yiran College of Internet of Things Nanjing University of Posts and Telecommunications Nanjing Jiangsu210003 China Key Lab of Broadband Wireless Communication and Sensor Network Technology of Ministry of Education Nanjing University of Post and Telecommunications Nanjing210003 China

Deployed in some unattended environment, the nodes of wireless sensor networks (WSNs) could be easily captured by the adversaries to become malicious nodes due to lack of appropriate protective measures. Therefore, how to protect the reliability of data transmission become an important issue in WSNs. In this paper, we mainly study the reliable data transmission technology of WSNs with malicious nodes. Firstly, the construction method of multipath secure routing is proposed, Then, a reliable data transmission algorithm for multi-path routing with secret sharing is designed. Experimental results show that the algorithm proposed in this paper has better performance than other methods. Copyright © 2016 American Scientific Publishers All rights reserved.

关键词： sensor nodes

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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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A RGB-D face recognition approach without confronting the camera

A RGB-D face recognition approach without confronting the ca...

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IEEE International Conference on Computer and communications, ICCC 2015

作者： Zhou, Wei Chen, Jian-Xin Wang, Lei Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing210003 China

ISBN: (纸本)9781467381253

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. © 2015 IEEE.

关键词： Face recognition

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A hybrid opportunistic Routing Scheme based on nodes grouping strategy for VANETs in Urban Scenarios

A hybrid opportunistic Routing Scheme based on nodes groupin...

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International Conference on wireless and Optical communications ( WOCC)

作者： Yuanfa Xie Jianmin Bao Zhihua Song Ya Zhou Bell Honors School Nanjing University of Posts and Telecommunications Nanjing China Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Jiangsu Provincial Engineering Research Center of Telecommunications and Network Technology Nanjing China

The increasing mobile devices with better wireless communication facilities trends to be a good opportunity for the development of vehicular ad-hoc networks (VANETs). The opportunistic routing protocols are generally developed from the Delay Tolerant network (DTN). In this paper, we propose an opportunistic routing algorithm called RSUS (Routing Scheme for Urban Scenarios) based on a grouping strategy which considers both internal property and external contacts of nodes. The nodes of network are divided into super nodes, backbone nodes and ordinary nodes. Each type of nodes uses different routing strategy respectively. Then simulations were carried out by the ONE simulator and evaluations compared with the traditional single opportunistic algorithms. Furthermore RSUS was simulated in three different cities. Results show that RSUS algorithm can obtain the optimal performance with a low network overhead ratio and a high delivery rate, it is also suitable for different urban scenarios.

关键词： Routing Urban areas Algorithm design and analysis wireless communication Ad hoc networks Delays Optical fiber communication

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Compressive Wideband Spectrum Sensing Based on Random Matrix Theory

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Journal of Donghua University(English Edition) 2015年第2期32卷 248-251页

作者：曹开田戴林燕杭燚灵张蕾顾凯冬 Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of EducationNanjing University of Posts and Telecommunications College of Overseas Education Nanjing University of Posts and Telecommunications

Spectrum sensing in a wideband regime for cognitive radio network(CRN) faces considerably technical challenge due to the constraints on analog-to-digital converters(ADCs).To solve this problem,an eigenvalue-based compressive wideband spectrum sensing(ECWSS) scheme using random matrix theory(RMT) was proposed in this *** ECWSS directly utilized the compressive measurements based on compressive sampling(CS) theory to perform wideband spectrum sensing without requiring signal recovery,which could greatly reduce computational complexity and data acquisition *** the ECWSS,to alleviate the communication overhead of secondary user(SU),the sensors around SU carried out compressive sampling at the sub-Nyquist rate instead of ***,the exact probability density function of extreme eigenvalues was used to set the *** analyses and simulation results show that compared with the existing eigenvalue-based sensing schemes,the ECWSS has much lower computational complexity and cost with no significant detection performance degradation.

关键词： compressive wideband Spectrum overhead exact eigenvalue utilized instead considerably constraints

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Enhancement of color image based on tone-preserving

Enhancement of color image based on tone-preserving

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International Conference on wireless communications and Signal Processing (WCSP)

作者： Ya'nan Yang Xiaofan Wang Feng Liu Zongliang Gan Jiangsu Province Key Lab on Image Processing & Image Communications Nanjing University of Posts and Telecommunications Nanjing China Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing University of Posts and Telecommunications Nanjing China

ISBN: (纸本)9781509028610

Since the lighting conditions in strong contrast regions between the light and dark cant be estimated accurately by traditional center/surround Retinex algorithm, the over-enhancement and color distortion may exist. In view of this, combining with the human visual characteristics, a color image enhancement algorithm based on tone-preserving was proposed. A determination function was added to the bilateral filter to estimate illuminance image more accurately and weaken over-enhancement. According to human visual masking effect, the improved gamma correction was utilized to correct the brightness of illumination image adaptively and the local contrast of reflection image obtained by division was enhanced based on local statistics. Besides, the final enhanced image was obtained by combining illumination image with reflection image, which can make image appear more natural. Compared with other similar algorithms from both subjective and objective aspects, the results show that this method being applied to low-contrast color image enhancement can not only improve image clarity, but reduce color distortion.

关键词： Image color analysis Brightness Lighting Color Visualization Nonlinear distortion

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