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2nd IEEE International Conference on Energy Internet, ICEI 2018

作者： Wu, Huan Wen, Xiangming Lu, Zhaoming Huang, Shuyang Beijing Key Laboratory of Network System Architecture and Convergence Beijing Laboratory of Advanced Information Networks Beijing University of Posts and Telecommunications Beijing100876 China School of Electronics and Information Engineering West Anhui University Lu'an237012 China

ISBN: (纸本)9781538641316

The Internet of Things (IoT) is a new heterogeneous system integrated by various end-users with different technologies. However, the limiting factor is bandwidth in the IoT due to exploding the end-users and the network bandwidth requirement. A novel IoT model, which integrates the Power Line Carrier (PLC) and the Wireless network (WN), is proposed to solve the bandwidth problem from the architecture, especially in the areas lacking network facilities. In addition, we exploit an effective virtual layer (EVL) which allows the different end-users access to the model seamlessly. Then, the attractor selection algorithm based on Markov chain (ASMA) is employed to select an optimal path among the PLC or the WN. Simulation results demonstrate that the proposed model has the smaller delay than other algorithms and makes the model more stable. © 2018 IEEE.

关键词： Internet of things

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A Compact Broadband Filter Using Triple-Mode Stepped-Impedance Stub-Loaded Resonator

A Compact Broadband Filter Using Triple-Mode Stepped-Impedan...

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2018 IEEE International Conference on Computational Electromagnetics, ICCEM 2018

作者： Li, Mingxing Wu, Yongle Qu, Meijun Liu, Yuanan Beijing University of Posts and Telecommunications State Key Laboratory of Information Photonics and Optical Communications School of Electronic Engineering Beijing China Sch. of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing Key Laboratory of Network System Architecture and Convergence Beijing China

ISBN: (纸本)9781538612415

In this paper, a compact broadband bandpass filter (BPF) using triple-mode stepped-impedance stub-loaded resonator (TMSISLR) is proposed. The TMSISLR is composed of an impedance-transforming unit and two asymmetrical open-ended stepped-impedance stubs (SIS) at the center. By simply adjusting the impedances of the SIS, the resonant frequencies of the TMSISLR can be flexibly changed. The interdigital coupled-lines are adopted to feed the proposed TMSISLR. This BPF can realize wide bandwidth, low insertion loss, high selectivity, and deep stopband rejection simultaneously. Finally, the proposed BPF is simulated, fabricated, and measured. The measured results show that the impedance bandwidth under-16.7 dB is 86% from 1.89 to 4.75 GHz, while the insertion loss is smaller than 1.47 dB. The measured insertion loss is larger than 30 dB at both low-and upper-stopband (from 0 to 1.27 GHz and 6.03 to 7.66 GHz). The measured results are in good agreement with the simulated counterpart. © 2018 IEEE.

关键词： Bandpass filters

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Transmission Capacity Analysis for Linear VANET under Physical Model

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China Communications 2017年第3期14卷 97-107页

作者： Xinxin He Hang Zhang Weisen Shi Tao Luo Norman C.Beaulieu Beijing Laboratory of Advanced Information Networks Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing 100876 China

In this study, the transmission capacity of VANETs in a highway scenario is analysed on the basis of a 1D line model and the carrier sense multiple access with collision avoidance(CSMA/CA) protocol. We describe the CSMA/CA protocol used in IEEE802.11 p from the perspective of the geometric relationship amongst simultaneous transmitters. The desired channel and interfering channels are assumed to experience the same amount of path-loss and Rayleigh fading. On the basis of the proposed model, we analyse the attempted transmission probability of each road segment and the maximum intensity of active transmitters, including their theoretical values. Then, we employ the physical model to obtain the outage probability and derive the upper bound of the transmission capacity of a VANET, which is defined as the average spatial density of successful transmissions in the network. Simulation results indicate that the theoretical value offers a good bound on network capacity.

关键词： VANET transmission capacity line model CSMA/CA

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Magnetically tunable terahertz all-dielectric metamaterial

arXiv

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arXiv 2018年

作者： Lan, Chuwen Wu, Hailian Yang, Daquan Gao, Zehua Beijing Laboratory of Advanced Information Networks Beijing Key Laboratory of Network System Architecture and Convergence Acknowledgment School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing100876 China

All-dielectric metamaterials composed of high index and low loss dielectric resonators have become a promising way for high-efficient optical devices. However, fabricating terahertz all-dielectric metamaterials and actively tuning their properties still remain challenges. In this paper, an effective method has been developed to prepare high-quality microspheres based all-dielectric metamaterial operating in terahertz (THz) range. Then, we propose a magnetically tunable THz all-dielectric metamaterial based on liquid crystal (LC). The all-dielectric metamaterial is immersed into LC and tuned by external magnetic field. We show that the induced Mie resonances can be effectively tuned by external magnetic field and the tunability is highly sensitive to the directors of applied magnetic field. A good tunability performance is obtained for the first electric resonance. This work provides a new method for high-quality THz all-dielectric metamaterials and paves a promising way for tunable THz all-dielectric metamaterial, which would find considerable applications in THz devices. Copyright © 2018, The Authors. All rights reserved.

关键词： Metamaterials

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Mm-Wave Low-Profile Wideband Antenna Array Using Low-temperature Co-fired Ceramics (LTCC) Technique

Mm-Wave Low-Profile Wideband Antenna Array Using Low-tempera...

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International Conference on Microwave and Millimeter Wave Technology Proceedings

作者： Jianfeng Zhu Yang Yang Chenhao Chu Shufang Li Shaowei Liao Quan Xue Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing China School of Electrical and Data Engineering University of Technology Sydney Ultimo NSW Australia School of Electronic and Information Engineering South China University of Technology Guangzhou China

A low-profile wideband and high gain patch antenna array using low-temperature co-fired ceramics (LTCC) fabrication technique is proposed for 60-GHz applications. Coupled feeding scheme is adopted so that the antenna achieves wide impedance bandwidth that covers the entire 60-GHz license-free band with the height of only 0.384 mm (four tape layers). The shorting pin connecting the upper patch and ground imitates the virtual ac ground plane of differential feeding. This enables the antenna element to achieve good radiation performances including stable gain, symmetrical beam with low cross-polarization, which are comparable to those of the differential-driven patch antenna while the complex differential feeding network is not required. Antenna array prototype is fabricated and measured to verify the idea.

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Modelling and Forecasting of Commodity Trading Price 2

Modelling and Forecasting of Commodity Trading Price

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2018 2nd International Conference on Data Mining, Communications and Information Technology, DMCIT 2018

作者： Liu, Jun Tian, Yuan Yan, Qing Center for Data Science BUPT Beijing100876 China School of Information and Communication Engineering BUPT Beijing100876 China Beijing Laboratory of Advanced Information Networks BUPT Beijing100876 China Beijing Key Laboratory of Network System Architecture and Convergence BUPT Beijing100876 China

This paper proposes and improves a model for China's cotton reserves trading market, generates a more accurate price level table in contrast to the widely used China Cotton Association(CCA)'s table, and predicts the future trading price with this model. Data used is all 29895 trade records of cotton reserves from May, 2016 to Sept, 2016. In this paper, we firstly give a briefly introduction to the data as well as basic knowledge of cotton, especially the CCA's price level table as the target to improve accuracy. We then present a multiple linear regression with dummy variable model, which can reduce the error on predicting the trading price of current month, but still remains some problems such as the result shows a batch of cotton with better quality may get a lower price. So we finally advance the model with multidimensional isotonic regression and more factors taken into consideration. Our last model could be used to predict the trade price of both current month and next month with approximately 4% mean absolute percentage error(MAPE). © Published under licence by IOP Publishing Ltd.

关键词： Cotton

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Localization of WiFi Devices Using Unmanned Aerial Vehicles in Search and Rescue

Localization of WiFi Devices Using Unmanned Aerial Vehicles ...

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IEEE International Conference on Communications in China Workshops (ICCC)

作者： Yunpeng Sun Xiangming Wen Zhaoming Lu Tao Lei Shan Jiang Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing

ISBN: (纸本)9781538670125;9781538670118

This paper presents an UAV (Unmanned Aerial Vehicle) system that can find the locations of the wireless devices such as smartphones and tablets in WiSAR (wildness search and rescue). By locating the wireless device, we can find the owner of it that get lost or get hurt in the wildness. The system contains a UAV armed with a wireless sniffer, a flight controller and data processing center. When the locating starts, the UAV will fly according to a planed route while the WiFi sniffer capturing the wireless signal from wireless devices. When the UAV discover the wireless device, a proposed algorithm will be executed to get the wireless device's distance and direction. And it will be executed iteratively until the UAV gets near enough. In order to avoid the environmental impact, we use the Kalman filter to process the RSSI (Received Signal Strength Indication). The experiments have proved that the proposed method is a fast and precise way to localize the wireless device.

关键词： Wireless communication Unmanned aerial vehicles Probes Kalman filters Wireless fidelity Mathematical model Conferences

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Research on co-frequency interference of CBTC signal based on IEEE 802.11 4

Research on co-frequency interference of CBTC signal based o...

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4th IEEE International Conference on Computer and Communications, ICCC 2018

作者： He, Xin Li, Jianfeng Wang, Ying Yang, Xuetao Wang, Wei Luo, Tao Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications China Beijing Laboratory of Advanced Information Networks Beijing University of Posts and Telecommunications China Beijing Radio Administration Bureau China Traffic Control Technology Co. Ltd. China

ISBN: (纸本)9781538683392

Communication-based train control (CBTC) systems adopt the wireless local area networks (WLAN) technology based on IEEE 802.11 protocol. The popularity of WiFi and other devices makes the 2.4 GHz co-frequency interference problem CBTC faced worse. In this paper, the reasons causing the CBTC systems to break in an emergency are analyzed: The co-frequency interference is too strong for the receivers to work properly;multiple users cause the CBTC signal's failure to access the channel or descending in performance of the receiver. Furthermore, field data test was designed and carried out on the subway line. After troubleshooting by analyzing the relevant parameters such as the number of packets, throughput, signal strength, etc., we find the amount of users requesting to connect to the Access Point (AP) 'EN' during rush hours is extremely high, which results in more heavy co-frequency interference and degradation in performance of the receiver. Regarding this serious situation, we propose improvement methods to guarantee the normal operation of CBTC systems. © 2018 IEEE.

关键词： Wireless local area networks (WLAN)

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Generation of Multiple Beams in Terahertz by Graphene-based Wideband Pancharatnam-Berry Coding Metasurface

Generation of Multiple Beams in Terahertz by Graphene-based ...

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2018 3rd International Conference on Computational Modeling, Simulation and Applied Mathematics (CMSAM 2018)

作者： Hong-jun WANG Li DENG Shu-fang LI Beijing Key Laboratory of Network System Architecture and Convergence Beijing Laboratory of Advanced Information Network Beijing University of Posts and Telecommunications Beijing

Nowadays, coding metasurface has raised more and more attention, but most of them focus on microwave domain. In this article, we design graphene-based coding metasurfaces utilizing the Pancharatnam-Berry(PB) phase principle in the terahertz(THz) regime. The coding metasurface could control circularly polarized incident waves over a wide bandwidth, by shifting the orientation angle of PB coding units, forming multiple beams with different polarizations. The numerical simulations have good agreements with the theoretical value, which opens an effective way to design novel multibeam antennas for future communication systems.

关键词： Coding metasurface Graphene Multiple beams Pancharatnam-Berry phase Circularly polarized waves

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Wideband Isosceles Trapezoid Dipole Array for Electromagnetic Energy Harvesting

Wideband Isosceles Trapezoid Dipole Array for Electromagneti...

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2018 3rd International Conference on Computational Modeling, Simulation and Applied Mathematics (CMSAM 2018)

作者： Xue-xing WANG Li DENG Shu-fang LI Beijing Key Laboratory of Network System Architecture and Convergence Beijing Laboratory of Advanced Information Network Beijing University of Posts and Telecommunications Beijing

In this paper, a novel energy harvesting dipole array based on two printed asymmetric off-center fed isosceles trapezoid dipoles is proposed. The dipole array not only has extremely high energy conversion efficiency, but also has wideband characteristics due to the isosceles trapezoidal electromagnetic structure. In order to verify the feasibility of design, the dipole cell and array are numerical simulated with ANSYS HFSS successively. For the alternating current(ac) conversion, the bandwidth with over 80% efficiency of cell reaches approximately 1 GHz, while the bandwidth with over 90% efficiency also approaches 0.6 GHz. Besides, when cells are expanded to an array, the array's performance can be further improved. The experimental results are in line with expectations.

关键词： Wireless power transfer (WPT) Energy harvesting Wideband Electromagnetic absorber Rectennas

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