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Ultra-low-power Backscatter-based software-defined radio for intelligent and simplified IoT network

Frontiers of Information Technology & Electronic Engineering 2022年第1期23卷 19-30页

作者： Huixin DONG Wei KUANG Fei XIAO Lihai LIU Feng XIANG Wei WANG Jianhua HE School of Electronic Information and Communication Huazhong University of Science and TechnologyWuhan430074China School of Management Huazhong University of Science and TechnologyWuhan430074China China Railway Siyuan Survey and Design Group Co. Ltd.Wuhan430063China Wuhan Maritime Communication Research Institute Wuhan430079China School of Computer Science and Electronic Engineering University of EssexColchesterCO43SQUK

The recent decade has witnessed an upsurge in the demands of intelligent and simplified Internet of Things(IoT)networks that provide ultra-low-power communication for numerous miniaturized devices.Although the research community has paid great attention to wireless protocol designs for these networks,researchers are handicapped by the lack of an energy-efficient software-defined radio(SDR)platform for fast implementation and experimental evaluation.Current SDRs perform well in battery-equipped systems,but fail to support miniaturized IoT devices with stringent hardware and power constraints.This paper takes the first step toward designing an ultra-low-power SDR that satisfies the ultra-low-power or even battery-free requirements of intelligent and simplified IoT networks.To achieve this goal,the core technique is the effective integration ofµW-level Backscatter in our SDR to sidestep power-hungry active radio frequency chains.We carefully develop a novel circuit design for efficient energy harvesting and power control,and devise a competent solution for eliminating the harmonic and mirror frequencies caused by Backscatter hardware.We evaluate the proposed SDR using different modulation schemes,and it achieves a high data rate of 100 kb/s with power consumption less than 200µW in the active mode and as low as 10µW in the sleep mode.We also conduct a case study of railway inspection using our platform,achieving 1 kb/s battery-free data delivery to the monitoring unmanned aerial vehicle at a distance of 50 m in a real-world environment,and provide two case studies on smart factories and logistic distribution to explore the application of our platform.

关键词： Backscatter Ultra-low-power SDR IoT networks

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A Green Paradigm for Internet of Things: Ambient Backscatter Communications

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China Communications 2019年第7期16卷 109-119页

作者： Wei Zhang Yao Qin Wenjing Zhao Minzheng Jia Qiang Liu Ruisi He Bo Ai Science and Technology on Information Systems Engineering Laboratory National University of Defense Technology and also with Institute of Telecommunication Satellites China Academy of Space Technology (CAST) Beijing Key Lab of Transportation Data Analysis and Mining Beijing Engineering Research Center of High-Speed Railway Broadband Mobile Communications School of Computer and Information Technology Beijing Jiaotong University Beijing 100044 China Department of Information Engineering Beijing Polytechnic College Beijing 100042 China State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong University Beijing 100044 China

Internet of Things (IoT) has attracted extensive interest from both academia and industries, and is recognized as an ultimate infrastructure to connect everything at anytime and anywhere. The implementation of IoT generally faces the challenges from energy constraint and implementation cost. In this paper, we will introduce a new green communication paradigm, the ambient Backscatter (AmBC), that could utilize the environmental wireless signals for both powering a tiny-cost device and Backscattering the information symbols. Specifically, we will present the basic principles of AmBC, analyze its features and advantages, suggest its open problems, and predict its potential applications for our future IoT.

关键词： ambient Backscatter (AmBC) RF-powered device Internet of Things (IoT) battery-free tag wire-less sensor

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An Overview on Backscatter Communications

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Journal of Communications and Information Networks 2019年第2期4卷 1-14页

作者： Jin-Ping Niu Geoffrey Ye Li Shaanxi International Joint Research Centre for the Battery-Free Internet of Things School of Information and TechnologyNorthwest UniversityXi’anShaanxi 710127China School of Electrical and Computer Engineering Georgia Institute of TechnologyAtlantaGA30332USA

As a key low-power communication tech-nique,Backscatter communications exploits the reflected or Backscattered signals to transmit data,where the Backscattered signals can be the reflection of ambient radio frequency(RF)signals,the RF signals from the dedicated carrier emitter or the signal photons in the non-classical quantum entangled pairs,etc.In the past 70 years,various kinds of Backscatter communication systems have been developed,which will enable the low-power communications as required in the Internet of things(IoTs)and green communications.This article provides a historical view on the development and the research achievements on Backscatter communications,including the fundamental principles,the applications,the challenges,and the potential research topics.This article will benefit the researchers and engineers concerning the area of Backscatter communications,especially for applications in IoTs.

关键词： Backscatter Backscatter communications energy harvesting IoTs

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基于Backscatter的无源阵列收发技术研究

基于backscatter的无源阵列收发技术研究

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作者：张开麟电子科技大学

学位级别：硕士

随着通信技术发展,广播信号、电视信号以及手机信号等无线信号无处不在。每时每刻存在的这些无线信号能量除了满足正常的通信实际上有很大一部分被浪费。如果能收集利用这些信号能量来为通信提供能量将会节省很大的能量开销。现有的无... 详细信息

随着通信技术发展,广播信号、电视信号以及手机信号等无线信号无处不在。每时每刻存在的这些无线信号能量除了满足正常的通信实际上有很大一部分被浪费。如果能收集利用这些信号能量来为通信提供能量将会节省很大的能量开销。现有的无线收发系统中由于有低噪放,功放,本振发生器等,导致系统的功耗很大,同时体积也比较大。RFID只实现了读卡器与标签之间的通信,而且其之间的通信速率很低。针对以上存在的问题,本文提出一种基于ESPAR(electronically steerable passive array radiator)的无源阵列收发技术。首先无源阵列天线收集能量来供电,同时接收空间信号来进行再调制,这种调制基于Backscatter由模拟电路来实现数字调制,相比较传统的数字调制其功耗很低。本文主要对于基于Backscatter的无源阵列收发技术的研究。首先本文引入一种新型的天线ESPAR来作为Backscatter模拟调制的天线,相比于其他阵列天线,其功耗很低。其是通过调节有源振子与无源阵子之间的耦合来对其方向性的控制来提高天线增益。本文的另一个研究内容是基于Backscatter的模拟调制,其基本原理是利用电路匹配与反射系数来实现不同的数字调制。相比于简单RFID其传输速率更大,能实现通信。在数字通信的时代模拟调制实现数字通信的方式还有待进一步研究。本文希望在已有的研究基础上能在Backscatter调制技术上有所突破以期能带来一种调制方式的同时实现功耗的降低。研究内容如下:1)介绍Backscatter模拟调试的特点与国内外发展现状。同时分析了基于Backscatter调制的通信链路,针对其特点提出一种与ESPAR阵列相结合的通信系统。并提出了其通信链路结构。2)基于ESPAR的Backscatter模拟调制的设计基础。本文介绍了模拟调制的技术原理、不同调制方式的设计要求及其实现方式,同时介绍了ESPAR的原理及实现形式。并且仿真与实际制作测试ESPAR阵列天线。3)Backscatter调制收发系统设计。本文设计分别设计了ASK、4ASK、4QAM、16QAM四种模拟方式的调制。首先对于不同的调制方式先设计计算不同的星座点同时计算出其对应的模拟调制所需的对应阻抗。其次画出四种模拟调制的原理图并进行PCB设计,最后利用ADS仿真软件辅助焊接调试。测试了系统直连情况和无线情况下的ASK、4ASK、4QAM三种调制的情况,并且依据测试结果对Backscatter调制系统的链路进行计算和预算。

关键词：模拟调制 Backscatter ESPAR 节能

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Ultrasonic Backscatter characterization of cancellous bone using a general Nakagami statistical model

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Chinese Physics B 2019年第2期28卷 313-320页

作者：刘成成东蕊李博艺李颖徐峰他得安王威琪 Institute of Acoustics School of Physics Science and EngineeringTongji University Department of Electronic Engineering Fudan University State Key Laboratory of ASIC and System Fudan University

The goal of this study is to analyze the statistics of the Backscatter signal from bovine cancellous bone using a Nakagami model and to evaluate the feasibility of Nakagami-model parameters for cancellous bone characterization. Ultrasonic Backscatter measurements were performed on 24 bovine cancellous bone specimens in vitro and the Backscatter signals were compensated for the frequency-dependent attenuation prior to the envelope detection. The statistics of the Backscatter envelope were modeled using the Nakagami distribution. Our results reveal that the Backscatter envelope mainly followed pre-Rayleigh distributions, and the deviations of the Backscatter envelope from Rayleigh distribution decreased with increasing bone density. The Nakagami shape parameter(i.e., m) was significantly correlated with bone densities(R = 0.78–0.81, p Backscatter bone evaluation.

关键词： ultrasonic Backscatter cancellous bone statistical analysis Nakagami model

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The Influence of IR Absorption and Backscatter Radiation from CO<sub>2</sub>on Air Temperature during Heating in a Simulated Earth/Atmosphere Experiment

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Atmospheric and Climate Sciences 2020年第2期10卷 168-185页

作者： Thorstein O. Seim Borgar T. Olsen

The Greenhouse Effect was simulated in a laboratory setup, consisting of a heated ground area and two chambers, one filled with air and one filled with air or CO2. While heating the gas the temperature and IR radiation in both chambers were measured. IR radiation was produced by heating a metal plate mounted on the rear wall. Reduced IR radiation through the front window was observed when the air in the foremost chamber was exchanged with CO2. In the rear chamber, we observed increased IR radiation due to Backscatter from the front chamber. Based on the Stefan Boltzmann’s law, this should increase the temperature of the air in the rear chamber by 2.4 to 4 degrees, but no such increase was found. A thermopile, made to increase the sensitivity and accuracy of the temperature measurements, showed that the temperature with CO2 increased slightly, about 0.5%.

关键词： Greenhouse Effect Radiative Forcing CO2 Backscatter IR Radiation

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TanDEM-X multiparametric data features in sea ice classification over the Baltic sea

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Geo-Spatial Information Science 2021年第2期24卷 313-332,I0009页

作者： Marjan Marbouti Oleg Antropov Jaan Praks Patrick B.Eriksson Vahid Arabzadeh Eero Rinne Matti Leppärant Institute for Atmospheric and Earth System Research/Physics Faculty of ScienceUniversity of HelsinkiHelsinkiFinland VTT Technical Research Centre of Finland EspooFinland Aalto University Department of Electronics and NanoengineeringEspooFinland Finnish Meteorological Institute HelsinkiFinland Aalto University Department of Applied PhysicsNew Energy Technologies GroupEspooFinland

In this study,we assess the potential of X-band Interferometric Synthetic Aperture Radar imagery for automated classification of sea ice over the Baltic Sea.A bistatic SAR scene acquired by the TanDEM-X mission over the Bothnian Bay in March of 2012 was used in the analysis.Backscatter intensity,interferometric coherence magnitude,and interferometric phase have been used as informative features in several classification experiments.Various combinations of classification features were evaluated using Maximum likelihood(ML),Random Forests(RF)and Support Vector Machine(SVM)classifiers to achieve the best possible discrimination between open water and several sea ice types(undeformed ice,ridged ice,moderately deformed ice,brash ice,thick level ice,and new ice).Adding interferometric phase and coherence-magnitude to Backscatter-intensity resulted in improved overall classification per-formance compared to using only Backscatter-intensity.The RF algorithm appeared to be slightly superior to SVM and ML due to higher overall accuracies,however,at the expense of somewhat longer processing time.The best overall accuracy(OA)for three methodologies were achieved using combination of all tested features were 71.56,72.93,and 72.91%for ML,RF and SVM classifiers,respectively.Compared to OAs of 62.28,66.51,and 63.05%using only Backscatter intensity,this indicates strong benefit of SAR interferometry in discriminating different types of sea ice.In contrast to several earlier studies,we were particularly able to successfully discriminate open water and new ice classes.

关键词： Sea ice classification Random Forests(RF) Maximum Likelihood(ML) Support Vector Machine(SVM) Backscatter coherence sar interferometry Synthetic Aperture Radar(SAR)

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On the heterogeneous microstructure development in the welded joint of 12MnNiVR pressure vessel steel subjected to high heat input electrogas welding

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Journal of Materials Science & Technology 2019年第8期35卷 1747-1752页

作者： Yang Shen Ju Leng Cong Wang School of Metallurgy Northeastern University Shenyang 110819 China Shenyang NEU New Industrial Technology Research Institute Co. LTD Shenyang 110819 China

Microstructure features of 12 MnNiVR pressure vessel steel welded joint deposited by the high heat input electrogas welding have been systematically investigated. It is revealed that the welded joint is featured by a heterogeneous juxtaposition. The coarse grained heat-affected zone(CGHAZ) primarily consists of lath bainites and minor granular bainites. The fine grained heat-affected zone(FGHAZ) is dominated by polygonal ferrites, pearlites, and fine cementite particles. Moreover, electron Backscatter diffraction results further demonstrate that the CGHAZ is populated by coarse prior austenite grains(PAGs) with high frequency(61.3%) of low angle grain boundaries(LAGBs). On the other hand, the FGHAZ is filled with fine PAGs with a lower frequency(19.6%) of LAGBs. Such microstructural differences may likely contribute to differed mechanical properties for samples tested at designed positions.

关键词： 12MnNiVR pressure vessel steel Electrogas welding High heat input Electron Backscatter diffraction

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A New Analysis Method for Locating the Focus and for Estimating the Size of the Focus of the Backscatter Light of a LIDAR System

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Journal of Electromagnetic Analysis and Applications 2010年第3期2卷 183-188页

作者： Nianwen Cao Weiyuan Wang Yonghua Wu Fred Moshary Zhongrong Chen Jiansong Huang School of Atmospheric Physics Nanjing University of Information Science & Technology Toshiba Stroke Research Center University at Buffalo Department of Electrical Engineering City College and Graduate School City University of New York

This paper presents a new analysis method for locating the focus and estimating the size of the focus of the Backscatter light of a Lidar system. The formula for calculating the uncertainty of the location of the focus of Backscatter light of a Lidar system is given, and the estimation of the size of the focus is also presented. This calculation coincides with the analysis result of ZEMAX software. By the analysis, the experiment to exactly locate the focus of the Backscatter light of Lidar is carried out.

关键词： Backscatter Light Focus Telescope

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Exploring the Potential of Mapping Cropping Patterns on Smallholder Scale Croplands Using Sentinel-1 SAR Data

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Chinese Geographical Science 2019年第4期29卷 626-639页

作者： Juliana USEYA CHEN Shengbo College of GeoExploration Science and Information Engineering Jilin University

It is of paramount importance to have sustainable agriculture since agriculture is the backbone of many nations’ economic development. Majority of agricultural professionals rarely capture the cropping patterns necessary to promote Good Agricultural Practises.Objective of this research is to explore the potential of mapping cropping patterns occurring on different field parcels on small-scale farmlands in Zimbabwe. The first study location under investigation are the International Maize and Wheat Improvement Center(CIMMYT) research station and a few neighboring fields, the second is Middle Sabi Estate. Fourier time series modeling was implemented to determine the trends befalling on the two study sites. Results reveal that Sentinel-1 synthetic aperture radar(SAR) time series allow detection of subtle changes that occur to the crops and fields respectively, hence can be utilized to detect cropping patterns on small-scale farmlands. Discrimination of the main crops(maize and soybean) grown at CIMMYT was possible, and crop rotation was synthesized where sowing starts in November. A single cropping of early and late crops was observed, there were no winter crops planted during the investigation period. At Middle Sabi Estate, single cropping on perennial sugarcane fields and triple cropping of fields growing leafy vegetables, tomatoes and onions were observed. Classification of stacked images was used to derive the crop rotation maps representing what is practised at the farming lands. Random forest classification of the multi-temporal image stacks achieved overall accuracies of 99% and 95% on the respective study sites. In conclusion, Sentinel-1 time series can be implemented effectively to map the cropping patterns and crop rotations occurring on small-scale farming land. We recommend the use of Sentinel-1 SAR multi-temporal data to spatially explicitly map cropping patterns of single-, double-and triple-cropping systems on both small-scale and large-scale farming areas to ensure food security.

关键词： cropping patterns polarized Backscatter time series Sentinel-1 SAR Zimbabwe

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