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Link Budget and Enhanced Communication Distance for Ambient Internet of Things

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ZTE Communications 2024年第1期22卷 16-23页

作者： YANG Yibing LIU Ming XU Rongtao wang gongpu GONG Wei School of Computer and Information Technology Beijing Jiaotong UniversityBeijing 100044China School of Electronic and Information Engineering Beijing Jiaotong UniversityBeijing 100044China School of Computer Science and Technology University of Science and Technology of ChinaHefei 230026China

Backscatter communications will play an important role in connecting everything for beyond 5G(B5G)and 6G *** open challenge for backscatter communications is that the signals suffer a round-trip path loss so that the communication distance is *** this paper,we first calculate the communication distance upper bounds for both uplink and downlink by measuring the tag sensitivity and reflection *** is found that the activation voltage of the envelope detection diode of the downlink tag is the main factor limiting the back-scatter communication *** on this analysis,we then propose to implement a low-noise amplifier(LNA)module before the envelope detection at the tag to enhance the incident signal *** experimental results on the hardware platform show that our method can increase the downlink communication range by nearly 20 m.

关键词： ambient IoT(AIoT) B5G backscatter communication link budget low-noise amplifier(LNA) Release 19 tag chip sensitivity upper bounds

Adaptabilities of different harvesters to peanut plants after cutting stalks

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International Journal of Agricultural and Biological Engineering 2022年第2期15卷 93-101页

作者： Youqing Chen gongpu wang Jiangtao wang Peng Zhang Bing wang Zhichao Hu Nanjing Institute for Agricultural Mechanization Ministry of Agriculture and Rural AffairsNanjing 210014China Henan Nongyouwang Agricultural Equipment Technology Co. Ltd.Zhumadian 463100HenanChina

At present,there are no harvesters specifically adapted to process peanuts after cutting *** particular,methods for harvesting peanuts after cutting stalks have not been reported thus ***,to utilize peanut stalks as feed when harvesting plastic-film-grown peanuts,and to improve industry benefits,a three-stage harvesting method is proposed *** view of the three-stage harvesting method,the peanut stalks are cut before digging,with the remaining peanut plants being shorter,thereby increasing the peanut pod-stalk *** investigate the adaptabilities of existing harvesters in harvesting peanuts after cutting stalks,three types of peanut harvesters-the self-propelled pick-up combine harvester,trailed pick-up combine harvester,and peanut picker were used to conduct a comparative test on harvesting intact peanut plants and plants after cutting *** loss,breakage and impurity rates were used as evaluation *** loss rates of these three harvesters were 14.64%,16.44%and 1.33%;the breakage rates were 21.28%,21.92%and 20.00%,and impurity rates were 4.60%,8.76%and 9.06%.Analysis of variance showed that cutting stalks had a significant impact on the work qualities of the three harvesters(p<0.05).With regard to the loss rate,results revealed that:the two peanut combine harvesters could not be adapted to harvest peanut plants after cutting *** three harvesters had good adaptability to harvest peanut plants after cutting stalks,considering the breakage rate;however,based on the impurity rate,the three harvesters could not be adapted to harvest peanut plants after cutting *** losses of the two combine harvesters consisted mainly of dropped and missed picking,with the sum of the losses accounting for 99.87%and 97.99%of the total losses of the two harvesters,respectively;this suggests that the drum pickup of the combine harvesters could not adapt to harvesting the peanut after cutting *** breakage rates of the three harvester

关键词： agricultural machinery peanut peanut harvesting after cutting stalks peanut combine harvester peanut picker adaptability research

Modeling and Channel Estimation for Piezo-Acoustic Backscatter Assisted Underwater Acoustic Communications

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China Communications 2022年第11期19卷 297-307页

作者： Junliang Lin gongpu wang Zijian Zheng Ruyi Ye Ruisi He Bo Ai School of Computer and Information Technology Beijing Jiaotong UniversityBeijing 100091China School of Electronic and Information Engineering Beijing Jiaotong UniversityBeijing 100091China China National Institute of Standardization Beijing 100088China The State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong UniversityBeijing 100091China

Relying on direct and converse piezoelectric effects,piezo-acoustic backscatter(PAB)technology reflects ambient acoustic signals to enable underwater backscatter communications at near-zero power,which was first realized through a *** this paper,we propose a mathematical model of the PAB assisted underwater acoustic(UWA)communication,and address the sparse channel estimation ***,we present a five-stage backscatter process to derive the backscatter coefficient,and propose the channel model for the shallow-water ***,we formulate the shallow-water acoustic channel estimation problem as a sparse vector recovery one according to the compressed sensing theory,and leverage the orthogonal matching pursuit(OMP)algorithm to obtain the channel ***,simulation results are provided to corroborate our proposed studies.

关键词： channel estimation compressed sensing piezo-acoustic backscatter underwater acoustic communications

Research and optimization of the hand-over lifting mechanism of a sweet potato combine harvester based on EDEM

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International Journal of Agricultural and Biological Engineering 2023年第5期16卷 71-79页

作者： Haiyang Shen Bing wang gongpu wang Yemeng wang Guocheng Bao Lianglong Hu Zhichao Hu Nanjing Institute of Agricultural Mechanization Ministry of Agriculture and Rural AffairsNanjing 210014China Chinese Academy of Agricultural Mechanization Sciences Group Co. Ltd.Beijing 100083China Graduate School of Chinese Academy of Agricultural Sciences Beijing 100081China

In order to meet the challenge of high loss rate and high tuber injury rate during the operation of the 4UZL-1 sweet potato combine harvester,the sweet potato tuber hand-over lifting mechanism was designed based on a comprehensive analysis of the entire structure of the *** the average normal force on conveying sweet potato tubers as evaluation indexes,the EDEM simulation experiment was carried out considering the factors of the angle of the excavating and conveying mechanism,the conveying angle of the scraper chain,the speed of the excavating and conveying mechanism,and the speed of the scraper chain *** experimental findings indicated that the optimal operational performance of the hand-over lifting mechanism was achieved at a speed of 1.15 m/s for the excavating and conveying mechanism,an angle of 24°for the excavating and conveying mechanism,a conveying speed of 0.66 m/s for the scraper chain,and a conveying angle of 60°for the scraper *** experiments were conducted based on the EDEM simulation experiment,using the loss rate and the injury rate of conveying sweet potato tubers as evaluation *** results showed that the hand-over lifting mechanism demonstrated optimal operational effectiveness with an excavating and conveying mechanism angle of 20°,a scraper chain angle of 68°,an excavating and conveying mechanism speed of 1.2 m/s,and a scraper chain speed of 0.66 m/s,while the machine running speed was maintained at 1 m/*** the moment,the hand-over lifting structure exhibited a loss rate of 1.12%and a tuber injury rate of 0.94%.The conclusions obtained serve as a valuable reference for future research and optimization of sweet potato combines.

关键词： agricultural mechanization sweet potato combine harvester hand-over and lifting mechanism EDEM simulation experiment field experiment

Symbiotic Radio Systems:Detection and Performance Analysis

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ZTE Communications 2022年第3期20卷 93-98页

作者： CUI Ziqi wang gongpu wang Zhigang AI Bo XIAO Huahua Beijing Jiaotong University Beijing 100044China Guangdong Communications and Networks Institute Guangzhou 510070China ZTE Corporation Shenzhen 518057China

Symbiotic radio(SR)is an emerging green technology for the Internet of Things(IoT).One key challenge of the SR systems is to design efficient and low-complexity detectors,which is the focus of this *** first drive the mathematical expression of the optimal maximum-likelihood(ML)detector,and then propose a suboptimal iterative detector with low ***,we show through numerical results that our proposed detector can obtain near-optimal bit error rate(BER)performance at a low computational cost.

关键词： bit error rate data detection Internet of Things symbiotic radio system wireless communication

Green Circuit Design for Battery-Free Sensors in Cloud Radio Access Network

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China Communications 2015年第11期12卷 1-11页

作者： ZENG Tengchan MA Zhen wang gongpu ZHONG Zhangdui School of Electronic and Information Engineering Beijing Jiaotong University School of Computer and Information Technology Beijing Jiaotong University

Cloud radio access network(C-RAN)is considered as a promising approach to solve the bandwidth crunch problem for future wireless network. Another important element for future network is sensors that can monitor physical or environmental conditions. Currently,most sensors need batteries for power,which is energy-consuming and maintenance-heavy. To further improve energy effi ciency(EE) of sensors in C-RAN,this paper proposes a new structure as well as practical circuit design for green sensors in C-RAN. The structure can enable sensors to harvest energy from radio signals transmitted by neighbor remote radio heads(RRHs) and user terminals(UTs). To demonstrate the validity of the new structure,a practical circuit design is suggested and the corresponding hardware platform is realized. Specifically,selection criteria for electrical component parameters and design of an impedance-matching network are discussed in details. In addition,two methods to stabilize the output voltage are proposed and analyzed. Finally,simulation results as well as experimental results are provided to corroborate our proposed studies.

关键词： energy harvesting C-RAN battery-free sensor efficiency

Channel Estimation and Throughput Evaluation for 5G Wireless Communication Systems in Various Scenarios on High Speed Railways

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China Communications 2018年第4期15卷 86-97页

作者： yanrong zhao xiyu wang gongpu wang ruisi he yulong zou zhuyan zhao school of computer and information technology beijing jiaotong universityBeijing 100044China the state key laboratory of rail traffic control and safety beijing jiaotong universityBeijing 100044China the key laboratory of broadband wireless communication and sensor network technology of ministry of education nanjing university of posts and telecommunicationsNanjing 210003China nokia bell labs beijing Beijing 100044China

The fifth generation(5 G) wireless communication is currently a hot research topic and wireless communication systems on high speed railways(HSR) are important applications of 5 G technologies. Existing studies about 5 G wireless systems on high speed railways(HSR) often utilize ideal channel parameters and are usually based on simple scenarios. In this paper, we evaluate the downlink throughput of 5 G HSR communication systems on three typical scenarios including urban, cutting and viaduct with three different channel estimators. The channel parameters of each scenario are generated with tapped delay line(TDL) models through ray-tracing simulations, which can be considered as a good match to practical situations. The channel estimators including least square(LS), linear minimum mean square error(LMMSE), and our proposed historical information based basis expansion model(Hi BEM). We analyze the performance of the Hi BEM estimator in terms of mean square error(MSE) and evaluate the system throughputs with different channel estimates over each scenario. Simulation results are then provided to corroborate our proposed studies. It is shown that our Hi BEM estimator outperforms other estimators and that the sys-

关键词：无线通讯系统评估系统隧道产量铁路评价阅读器无线系统

Backscatter t echnologies and the future of Internet of Things:Challenges and opportunities

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Intelligent and Converged Networks 2020年第2期1卷 170-180页

作者： Chaochao Yao Yang Liu Xusheng Wei gongpu wang Feifei Gao Beijing Key Lab of Transportation Data Analysis and Mining School of Computer and Information TechnologyBeiijing Jiaotong UniversityBeijing 100044China Beijing Institute of Aerospace Control Devices Beijing 100854China VIVO Mobile Company Beijing 100015China Department of Automation Tsinghua UniversityBeijing 100084China

Energy source and circuit cost are two critical challenges for the future development of the Internet of Things(IoT).Backscatter communications offer a potential solution to conveniently obtain power and reduce cost for sensors in IoT,and researchers are paying close attention to the *** technology originated from the Second World War and has been widely applied in the logistics ***,both the academic and industrial worlds are proposing a series of new types of backscatter technologies for communications and *** this paper,we review the history of both IoT and backscatter,describe the new types of backscatter,demonstrate their applications,and discuss the open challenges.

关键词： ambient backscatter backscatter communications battery-less sensor Internet of Things(IoT) Large Intelligent Surface(LIS) Unmanned Aerial Vehicle(UAV)

AoA-Based Channel Estimation for Massive MIMO OFDM Communication Systems on High Speed Rails

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China Communications 2020年第3期17卷 90-100页

作者： Yanrong Zhao Wenjing Zhao gongpu wang Bo Ai Hervin Hidayat Putra Bagus Juliyanto School of Computer and Information Technology Beijing Jiaotong UniversityBeijing 100044China the State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong UniversityBeijing 100044China School of Electrical Engineering and Informatics Bandung Institute of TechnologyBandungIndonesia

Channel estimation is a well-known challenge for wireless orthogonal frequency division multiplexing(OFDM)communication systems with massive antennas on high speed rails(HSRs).This paper investigates this problem and design two practicable uplink and downlink channel estimators for orthogonal frequency division multiplexing(OFDM)communication systems with massive antenna arrays at base station on ***,we first use pilots to estimate the initial angle of arrival(AoA)and channel gain information of each uplink path through discrete Fourier transform(DFT),and then refine the estimates via the angle rotation technique and suggested pilot *** on the uplink angel estimation,we design a new downlink channel estimator for frequency division duplexing(FDD)***,we derive the Cramér-Rao lower bounds(CRLBs)of the AoA and channel gain ***,numerical results are provided to corroborate our proposed studies.

关键词： massive MIMO high speed rail channel estimation AoA OFDM