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Robust and Passive Motion Detection with COTS WiFi Devices

Tsinghua Science and Technology 2017年第4期22卷 345-359页

作者： Hai Zhu Fu Xiao Lijuan Sun Xiaohui Xie Panlong Yang Ruchuan Wang the College of Computer Nanjing University of Posts and Telecommunications the Jiangsu High Technology Research Key Laboratory for Wireless Sensor Networks Key Lab of Broadband Wireless Communication and Sensor Network Technology of Ministry of Education and College of Computer Nanjing University of Posts and Telecommunications the College of Computer Science and Technology University of Science and Technology of China

Device-free Passive（DfP） detection has received increasing attention for its ability to support various pervasive applications. Instead of relying on variable Received Signal Strength（RSS）, most recent studies rely on finer-grained Channel State Information（CSI）. However, existing methods have some limitations, in that they are effective only in the Line-Of-Sight（LOS） or for more than one moving individual. In this paper, we analyze the human motion effect on CSI and propose a novel scheme for Robust Passive Motion Detection（R-PMD）. Since traditional low-pass filtering has a number of limitations with respect to data denoising, we adopt a novel Principal Component Analysis（PCA）-based filtering technique to capture the representative signals of human motion and extract the variance profile as the sensitive metric for human detection. In addition, existing schemes simply aggregate CSI values over all the antennas in MIMO systems. Instead, we investigate the sensing quality of each antenna and aggregate the best combination of antennas to achieve more accurate and robust detection. The R-PMD prototype uses off-the-shelf WiFi devices and the experimental results demonstrate that R-PMD achieves an average detection rate of 96.33% with a false alarm rate of 3.67%.

关键词： device-free passive detection Received Signal Strength(RSS) channel state information MIMO

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A QoS-aware routing algorithm based on ant-cluster in wireless multimedia sensor networks

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Science China(Information Sciences) 2014年第10期57卷 77-92页

作者： HUANG HaiPing CAO Xiao WANG RuChuan WEN YongGang 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 of Ministry of Education Nanjing University of Posts and Telecommunications School of Computer Engineering Nanyang Technological University

QoS-aware routing algorithm is important in wireless multimedia sensor networks. This paper formulates a generalized QoS-aware routing model on the basis of multiple routing metrics and priorities of packets. We first introduce a 2D plain-based routing algorithm IPACR which improves the standard ant colony algorithm by optimizing the initial distribution of artificial pheromone in order to accelerate the algorithm convergence rate. Then a clustering-based routing algorithm ICACR is presented which can be well applied in a large scale network. ICACR is a variation of IPACR because it can be suitable for clustering cases to satisfy the larger scale situations. Both the numerical algorithm performance analysis and simulation of IPACR and ICACR are given. The results show that ICACR outperforms IPACR in terms of both network lifetime and QoS-aware routing metrics in large scale wireless multimedia sensor networks. Moreover, the simulation based on the real video traces shows that by extending the multi-path to ICACR for different priorities of video frames better performance can be achieved.

关键词： ant colony clustering-based multi-path QoS-aware routing algorithm wireless multimedia sensor networks

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Optimal entanglement concentration for three-photon W states with parity check measurement

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Chinese Physics B 2013年第2期22卷 97-104页

作者：周澜盛宇波赵生妹 College of Mathematics & Physics Nanjing University of Posts and Telecommunications Key Laboratory of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Ministry of Education National Laboratory of Solid State Microstructures Nanjing University

We present an efficient entanglement concentration protocol（ECP） for the less-entangled W state with some identical conventional polarized single *** the protocol,two of the parties say Alice and Charlie should perform the parity check measurements and they can ultimately obtain the maximally entangled W state with a certain success ***,they can obtain another less-entangled W state,which can be reconcentrated into the maximally entangled W *** iterating this ECP,a high success probability can be *** ECP may be an optimal one and it is useful in current quantum information processing.

关键词： quantum communication entanglement entanglement concentration

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Low-power task scheduling algorithm for large-scale cloud data centers

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Journal of Systems Engineering and Electronics 2013年第5期24卷 870-878页

作者： Xiaolong Xu Jiaxing Wu Geng Yang Ruchuan Wang College of Computer Nanjing University of Posts and Telecommunications State Key Laboratory for Novel Software Technology Nanjing University Key Lab of Broadband Wireless Communication and Sensor Network Technology of Ministry of Education Nanjing University of Posts and Telecommunications

How to effectively reduce the energy consumption of large-scale data centers is a key issue in cloud computing. This paper presents a novel low-power task scheduling algorithm （L3SA） for large-scale cloud data centers. The winner tree is introduced to make the data nodes as the leaf nodes of the tree and the final winner on the purpose of reducing energy consumption is selected. The complexity of large-scale cloud data centers is fully consider, and the task comparson coefficient is defined to make task scheduling strategy more reasonable. Experiments and performance analysis show that the proposed algorithm can effectively improve the node utilization, and reduce the overall power consumption of the cloud data center.

关键词： cloud computing data center task scheduling energy consumption.

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Analysis and Optimization on Partition-Based Caching and Delivery in Satellite-Terrestrial Edge Computing networks

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China communications 2023年第3期20卷 252-285页

作者： Peng Wang Xing Zhang Jiaxin Zhang Shuang Zheng Wenhao Liu Wireless Signal Processing and Network Laboratory Key Laboratory of Universal Wireless CommunicationMinistry of EducationSchool of Information and Communication EngineeringBeijing University of Posts and TelecommunicationsBeijing 100876China

As a viable component of 6G wireless communication architecture,satellite-terrestrial networks support efficient file delivery by leveraging the innate broadcast ability of satellite and the enhanced powerful file transmission approaches of multi-tier terrestrial *** the paper,we introduce edge computing technology into the satellite-terrestrial network and propose a partition-based cache and delivery strategy to make full use of the integrated resources and reducing the backhaul *** on the interference effect from varied nodes in different geographical distances,we derive the file successful transmission probability of the typical user and by utilizing the tool of stochastic *** the constraint of nodes cache space and file sets parameters,we propose a near-optimal partition-based cache and delivery strategy by optimizing the asymptotic successful transmission probability of the typical *** complex nonlinear programming problem is settled by jointly utilizing standard particle-based swarm optimization(PSO)method and greedy based multiple knapsack choice problem(MKCP)optimization *** results show that compared with the terrestrial only cache strategy,Ground Popular Strategy,Satellite Popular Strategy,and Independent and identically distributed popularity strategy,the performance of the proposed scheme improve by 30.5%,9.3%,12.5%and 13.7%.

关键词： edge computing satellite terrestrial net-works caching deployment stochastic geometry 6G networks

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Optical encryption scheme based on ghost imaging with disordered speckles

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Chinese Physics B 2017年第5期26卷 160-164页

作者：张玉东赵生妹 Institute of Signal Processing and Transmission Nanjing University of Posts and Telecommunications Nanjing 210003 China Key Laboratory of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing 210003 China

An optical encryption scheme based on a ghost imaging system with disordered speckles is proposed to obtain a higher security with a small key. In the scheme, Alice produces the random speckle patterns and obtains the detection results with the help of a computational ghost imaging（CGI） system. Then Alice permutes the order of the random speckle patterns and shares the permutation sequence as a secure key to the authorized users. With the secure key, Bob could recover the object with the principle of the CGI system, whereas, the unauthorized users could not obtain any information of the object. The numerical simulations and experimental results show that the proposed scheme is feasible with a small key, simultaneously,it has a higher security. When the eavesdropping ratio（ER） is less than 40%, the eavesdropper cannot acquire any useful information. Meanwhile, the authorized users could recover completely with the secure key.

关键词： ghost encryption secure speckle recover authorized disordered users reconstructed PSNR

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Channel measurements and models for high-speed train wireless communication systems in tunnel scenarios: a survey

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Science China(Information Sciences) 2017年第10期60卷 107-123页

作者： Yu LIU Ammar GHAZAL Cheng-Xiang WANG Xiaohu GE Yang YANG Yapei ZHANG Shandong Provincial Key Laboratory of Wireless Communication Technologies Shandong University School of Engineering and Sustainable Development De Montfort University Institute of Sensors Signals and Systems School of Engineering & Physical Sciences Heriot-Watt University Department of Electronics and Information Engineering Huazhong University of Science and Technology Key Laboratory of Wireless Sensor Network & Communication Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences

The rapid developments of high-speed trains(HSTs) introduce new challenges to HST wireless communication systems. Realistic HST channel models play a critical role in designing and evaluating HST communication systems. Due to the length limitation, bounding of tunnel itself, and waveguide effect, channel characteristics in tunnel scenarios are very different from those in other HST scenarios. Therefore, accurate tunnel channel models considering both large-scale and small-scale fading characteristics are essential for HST communication systems. Moreover, certain characteristics of tunnel channels have not been investigated sufficiently. This article provides a comprehensive review of the measurement campaigns in tunnels and presents some tunnel channel models using various modeling methods. Finally, future directions in HST tunnel channel measurements and modeling are discussed.

关键词： 5G high-speed train(HST) tunnel scenario tunnel channel measurement tunnel channel model non-stationary statistical property

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A novel channel estimation method for clipped OFDM systems based on virtual pilots

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Journal of Computational Information Systems 2012年第5期8卷 1905-1912页

作者： Xie, Yongsheng Zhou, Leilei Fu, Yaoxian Key Lab. of Wireless Sensor Network and Communication Shanghai Institute of Microsystem and Information Technology CAS Shanghai 200050 China

Data as well as pilot symbols are nonlinearly distorted due to signal clipping in practical OFDM systems. The distortion inflicted on pilot symbols has great negative effect on the channel estimation. To solve this issue, a novel iterative channel estimation algorithm based on virtual pilots is introduced for clipped OFDM systems in this paper. The algorithm iteratively estimates nonlinear distortion of data symbols, and subsequently uses it for data detection. Then part or all of the detected data symbols are used as virtual pilots to perform more precise channel re-estimation. The MSE of channel estimation is derived theoretically. Simulation results show that the proposal improves the performance remarkably with moderate complexity increase at the receiver. In particular, compared to traditional algorithm, the BER performance of this method increases by 0.3 dB. © 2012 Binary Information Press.

关键词： Peak to average power ratio

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Compressed ghost imaging based on differential speckle patterns

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Chinese Physics B 2020年第2期29卷 294-300页

作者： Le Wang Shengmei Zhao Institute of Signal Processing and Transmission Nanjing University of Posts and Telecommunications(NUPT)Nanjing 210003China Key Laboratory of Broadband Wireless Communication and Sensor Network Technology(NUPT) Ministry of EducationNanjing 210003China

We propose a compressed ghost imaging scheme based on differential speckle patterns,named *** the scheme,a series of bucket detector signals are acquired when a series of random speckle patterns are employed to illuminate an unknown *** the differential speckle patterns(differential bucket detector signals)are obtained by taking the difference between present random speckle patterns(present bucket detector signals)and previous random speckle patterns(previous bucket detector signals).Finally,the image of object can be obtained directly by performing the compressed sensing algorithm on the differential speckle patterns and differential bucket detector *** experimental and simulated results reveal that CGI-DSP can improve the imaging quality and reduce the number of measurements comparing with the traditional compressed ghost imaging schemes because our scheme can remove the environmental illuminations efficiently.

关键词： ghost imaging compressed sensing differential speckle patterns differential bucket detector signals

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Graph theory based physical cell identity self-configuration for LTE-A network

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The Journal of China Universities of Posts and Telecommunications 2013年第1期20卷 101-107页

作者： WEI Yao WANG Wen-bo PENG Mu-gen MIN Shi-jun Key Laboratory of Universal Wireless Communication Ministry of Education Beijing University of Posts and Telecommunications Wireless Signal Processing and Network Laboratory Beijing University of Posts and Telecommunications

Self-configuration of physical cell identity （PCI） is a key feature for the long term evolution advanced （LTE-A） network. The PCI is used to identify the different cells in the system, becoming an essential cell configuration parameter. Considering the uncoordinated deployments of the evolved Node B （eNodeB） and the limited number of PCI, the PCI assignment for cells would be quite complex. This paper presents and puts forward a graph theory based centralized PCI self-configuration scheme （GT-PCIS）. The PCI self-configuration problem is mapped to the well-known minimum spanning tree （MST） problem in order to optimize the PCI reuse distance and decrease the multiplexing interference throughout the entire network. The proposal provides a greedy search to make the locally optimal selection of PCI at each stage, and to achieve a global optimum. To demonstrate the algorithm validity, performances of GT-PCIS and manual configuration are evaluated. Simulation results show that the proposed GT-PCIS outperforms other configuration algorithms even under the condition of severe PCI deficiency.

关键词： LTE-A PCI MST self-configuration

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