期刊文献+
共找到26篇文章
< 1 2 >
每页显示 20 50 100
Performance Limits and Advancements in Single 2D Transition Metal Dichalcogenide Transistor
1
作者 Jing Chen Ming-Yuan Sun +8 位作者 Zhen-Hua Wang Zheng Zhang Kai Zhang Shuai Wang Yu Zhang Xiaoming Wu Tian-Ling Ren Hong Liu Lin Han 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第12期134-188,共55页
Two-dimensional(2D)transition metal dichalcogenides(TMDs)allow for atomic-scale manipulation,challenging the conventional limitations of semiconductor materials.This capability may overcome the short-channel effect,sp... Two-dimensional(2D)transition metal dichalcogenides(TMDs)allow for atomic-scale manipulation,challenging the conventional limitations of semiconductor materials.This capability may overcome the short-channel effect,sparking significant advancements in electronic devices that utilize 2D TMDs.Exploring the dimension and performance limits of transistors based on 2D TMDs has gained substantial importance.This review provides a comprehensive investigation into these limits of the single 2D-TMD transistor.It delves into the impacts of miniaturization,including the reduction of channel length,gate length,source/drain contact length,and dielectric thickness on transistor operation and performance.In addition,this review provides a detailed analysis of performance parameters such as source/drain contact resistance,subthreshold swing,hysteresis loop,carrier mobility,on/off ratio,and the development of p-type and single logic transistors.This review details the two logical expressions of the single 2D-TMD logic transistor,including current and voltage.It also emphasizes the role of 2D TMD-based transistors as memory devices,focusing on enhancing memory operation speed,endurance,data retention,and extinction ratio,as well as reducing energy consumption in memory devices functioning as artificial synapses.This review demonstrates the two calculating methods for dynamic energy consumption of 2D synaptic devices.This review not only summarizes the current state of the art in this field but also highlights potential future research directions and applications.It underscores the anticipated challenges,opportunities,and potential solutions in navigating the dimension and performance boundaries of 2D transistors. 展开更多
关键词 Two-dimensional transistors Dimension limits Performance limits Memory devices Artificial synapses
在线阅读 下载PDF
Codebook Design and Beam Training for Extremely Large-Scale RIS:Far-Field or Near-Field? 被引量:14
2
作者 Xiuhong Wei Linglong Dai +2 位作者 Yajun Zhao Guanghui Yu Xiangyang Duan 《China Communications》 SCIE CSCD 2022年第6期193-204,共12页
Reconfigurable intelligent surface(RIS)is more likely to develop into extremely large-scale RIS(XL-RIS)to efficiently boost the system capacity for future 6 G communications.Beam training is an effective way to acquir... Reconfigurable intelligent surface(RIS)is more likely to develop into extremely large-scale RIS(XL-RIS)to efficiently boost the system capacity for future 6 G communications.Beam training is an effective way to acquire channel state information(CSI)for XL-RIS.Existing beam training schemes rely on the far-field codebook.However,due to the large aperture of XL-RIS,the scatters are more likely to be in the near-field region of XL-RIS.The far-field codebook mismatches the near-field channel model.Thus,the existing far-field beam training scheme will cause severe performance loss in the XL-RIS assisted nearfield communications.To solve this problem,we propose the efficient near-field beam training schemes by designing the near-field codebook to match the nearfield channel model.Specifically,we firstly design the near-field codebook by considering the near-field cascaded array steering vector of XL-RIS.Then,the optimal codeword for XL-RIS is obtained by the exhausted training procedure.To reduce the beam training overhead,we further design a hierarchical nearfield codebook and propose the corresponding hierarchical near-field beam training scheme,where different levels of sub-codebooks are searched in turn with reduced codebook size.Simulation results show the proposed near-field beam training schemes outperform the existing far-field beam training scheme. 展开更多
关键词 extremely large-scale RIS near-field codebook design beam training
在线阅读 下载PDF
Wideband Channel Estimation for THz Massive MIMO 被引量:6
3
作者 Jingbo Tan Linglong Dai 《China Communications》 SCIE CSCD 2021年第5期66-80,共15页
Terahertz(THz)communication is considered to be a promising technology for future 6G network.To overcome the severe attenuation and relieve the high power consumption,massive multipleinput multiple-output(MIMO)with hy... Terahertz(THz)communication is considered to be a promising technology for future 6G network.To overcome the severe attenuation and relieve the high power consumption,massive multipleinput multiple-output(MIMO)with hybrid precoding has been widely considered for THz communication.However,accurate wideband channel estimation,which is essential for hybrid precoding,is challenging in THz massive MIMO systems.The existing wideband channel estimation schemes based on the ideal assumption of common sparse channel support will suffer from a severe performance loss due to the beam split effect.In this paper,we propose a beam split pattern detection based channel estimation scheme to realize reliable wideband channel estimation in THz massive MIMO systems.Specifically,a comprehensive analysis on the angle-domain sparse structure of the wideband channel is provided by considering the beam split effect.Based on the analysis,we define a series of index sets called as beam split patterns,which are proved to have a one-to-one match to different physical channel directions.Inspired by this one-to-one match,we propose to estimate the physical channel direction by exploiting beam split patterns at first.Then,the sparse channel supports at different subcarriers can be obtained by utilizing a support detection window.This support detection window is generated by expanding the beam split pattern which is determined by the obtained physical channel direction.The above estimation procedure will be repeated path by path until all path components are estimated.Finally,the wideband channel can be recovered by calculating the elements on the total sparse channel support at all subcarriers.The proposed scheme exploits the wideband channel property implied by the beam split effect,i.e.,beam split pattern,which can significantly improve the channel estimation accuracy.Simulation results show that the proposed scheme is able to achieve higher accuracy than existing schemes. 展开更多
关键词 THz communication massive MIMO hybrid precoding beam split wideband channel estimation
在线阅读 下载PDF
The Roadmap of 2D Materials and Devices Toward Chips 被引量:5
4
作者 Anhan Liu Xiaowei Zhang +16 位作者 Ziyu Liu Yuning Li Xueyang Peng Xin Li Yue Qin Chen Hu Yanqing Qiu Han Jiang Yang Wang Yifan Li Jun Tang Jun Liu Hao Guo Tao Deng Songang Peng He Tian Tian‑Ling Ren 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第6期343-438,共96页
Due to the constraints imposed by physical effects and performance degra certain limitations in sustaining the advancement of Moore’s law.Two-dimensional(2D)materials have emerged as highly promising candidates for t... Due to the constraints imposed by physical effects and performance degra certain limitations in sustaining the advancement of Moore’s law.Two-dimensional(2D)materials have emerged as highly promising candidates for the post-Moore era,offering significant potential in domains such as integrated circuits and next-generation computing.Here,in this review,the progress of 2D semiconductors in process engineering and various electronic applications are summarized.A careful introduction of material synthesis,transistor engineering focused on device configuration,dielectric engineering,contact engineering,and material integration are given first.Then 2D transistors for certain electronic applications including digital and analog circuits,heterogeneous integration chips,and sensing circuits are discussed.Moreover,several promising applications(artificial intelligence chips and quantum chips)based on specific mechanism devices are introduced.Finally,the challenges for 2D materials encountered in achieving circuit-level or system-level applications are analyzed,and potential development pathways or roadmaps are further speculated and outlooked. 展开更多
关键词 Two-dimensional materials ROADMAP Integrated circuits Post-Moore era
在线阅读 下载PDF
Optoelectronic Synapses Based on MXene/Violet Phosphorus van der Waals Heterojunctions for Visual‑Olfactory Crossmodal Perception 被引量:3
5
作者 Hailong Ma Huajing Fang +3 位作者 Xinxing Xie Yanming Liu He Tian Yang Chai 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第6期38-52,共15页
The crossmodal interaction of different senses,which is an important basis for learning and memory in the human brain,is highly desired to be mimicked at the device level for developing neuromorphic crossmodal percept... The crossmodal interaction of different senses,which is an important basis for learning and memory in the human brain,is highly desired to be mimicked at the device level for developing neuromorphic crossmodal perception,but related researches are scarce.Here,we demonstrate an optoelectronic synapse for vision-olfactory crossmodal perception based on MXene/violet phosphorus(VP)van der Waals heterojunctions.Benefiting from the efficient separation and transport of photogenerated carriers facilitated by conductive MXene,the photoelectric responsivity of VP is dramatically enhanced by 7 orders of magnitude,reaching up to 7.7 A W^(−1).Excited by ultraviolet light,multiple synaptic functions,including excitatory postsynaptic currents,pairedpulse facilitation,short/long-term plasticity and“learning-experience”behavior,were demonstrated with a low power consumption.Furthermore,the proposed optoelectronic synapse exhibits distinct synaptic behaviors in different gas environments,enabling it to simulate the interaction of visual and olfactory information for crossmodal perception.This work demonstrates the great potential of VP in optoelectronics and provides a promising platform for applications such as virtual reality and neurorobotics. 展开更多
关键词 Violet phosphorus MXene Van der Waals heterojunctions Optoelectronic synapses Crossmodal perception
在线阅读 下载PDF
Recent Advance in Synaptic Plasticity Modulation Techniques for Neuromorphic Applications 被引量:1
6
作者 Yilin Sun Huaipeng Wang Dan Xie 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第10期403-434,共32页
Manipulating the expression of synaptic plasticity of neuromorphic devices provides fascinating opportunities to develop hardware platforms for artifi-cial intelligence.However,great efforts have been devoted to explo... Manipulating the expression of synaptic plasticity of neuromorphic devices provides fascinating opportunities to develop hardware platforms for artifi-cial intelligence.However,great efforts have been devoted to exploring biomimetic mechanisms of plasticity simulation in the last few years.Recent progress in various plasticity modulation techniques has pushed the research of synaptic electronics from static plasticity simulation to dynamic plasticity modulation,improving the accuracy of neuromorphic computing and providing strategies for implementing neuromorphic sensing functions.Herein,several fascinating strategies for synap-tic plasticity modulation through chemical techniques,device structure design,and physical signal sensing are reviewed.For chemical techniques,the underly-ing mechanisms for the modification of functional materials were clarified and its effect on the expression of synaptic plasticity was also highlighted.Based on device structure design,the reconfigurable operation of neuromorphic devices was well demonstrated to achieve programmable neuromorphic functions.Besides,integrating the sensory units with neuromorphic processing circuits paved a new way to achieve human-like intelligent perception under the modulation of physical signals such as light,strain,and temperature.Finally,considering that the relevant technology is still in the basic exploration stage,some prospects or development suggestions are put forward to promote the development of neuromorphic devices. 展开更多
关键词 Plasticity modulation Dynamic plasticity Chemical techniques Programmable operation Neuromorphic sensing
在线阅读 下载PDF
Survey of Attacks and Countermeasures for SDN
7
作者 BAI Jiasong ZHANG Menghao BI Jun 《ZTE Communications》 2018年第4期3-8,共6页
Software defined networking(SDN)has attracted significant attention from both academia and industry by its ability to reconfigure network devices with logically centralized applications.However,some critical security ... Software defined networking(SDN)has attracted significant attention from both academia and industry by its ability to reconfigure network devices with logically centralized applications.However,some critical security issues have also been introduced along with the benefits,which put an obstruction to the deployment of SDN.One root cause of these issues lies in the limited resources and capability of devices involved in the SDN architecture,especially the hardware switches lied in the data plane.In this paper,we analyze the vulnerability of SDN and present two kinds of SDN-targeted attacks:1)data-to-control plane saturation attack which exhausts resources of all SDN components,including control plane,data plane,and the in-between downlink channel and 2)control plane reflection attack which only attacks the data plane and gets conducted in a more efficient and hidden way.Finally,we propose the corresponding defense frameworks to mitigate such attacks. 展开更多
关键词 SDN indirect/direct data plane event data-to-control plane saturation attack control plane reflection attack
在线阅读 下载PDF
DetSpace:Distributed Congestion Free Routing for Global Deterministic Network in Mega-Constellations
8
作者 Li Jihao Li Hewu +1 位作者 Lai Zeqi Wang Xiaomo 《China Communications》 SCIE CSCD 2024年第12期203-216,共14页
Emerging long-range industrial IoT applications(e.g.,remote patient monitoring)have increasingly higher requirements for global deterministic delay.Although many existing methods have built deterministic networks in s... Emerging long-range industrial IoT applications(e.g.,remote patient monitoring)have increasingly higher requirements for global deterministic delay.Although many existing methods have built deterministic networks in small-scale networks through centralized computing and resource reservation,they cannot be applied on a global scale.The emerging mega-constellations enable new opportunities for realizing deterministic delay globally.As one constellation(e.g.,Starlink)might be managed by a single operator(e.g.,SpaceX),packets can be routed within deterministic number of hops.Moreover,the path diversity brought by the highly symmetrical network structure in mega-constellations can help to construct a congestion free network by routing.This paper leverages these unique characteristics of mega-constellations to avoid the traditional network congestion caused by multiple inputs and single output,and to determine the routing hops,and thus realizing a global deterministic network(DETSPACE).The model based on the 2D Markov chain theoretically verifies the correctness of DETSPACE.The effectiveness of DETSPACE in different traffic load con-ditions is also verified by extensive simulations. 展开更多
关键词 congestion free deterministic network mega-constellations path diversity
在线阅读 下载PDF
Privacy-Preserving Federated Mobility Prediction with Compound Data and Model Perturbation Mechanism
9
作者 Long Qingyue Wang Huandong +4 位作者 Chen Huiming Jin Depeng Zhu Lin Yu Li Li Yong 《China Communications》 SCIE CSCD 2024年第3期160-173,共14页
Human mobility prediction is important for many applications.However,training an accurate mobility prediction model requires a large scale of human trajectories,where privacy issues become an important problem.The ris... Human mobility prediction is important for many applications.However,training an accurate mobility prediction model requires a large scale of human trajectories,where privacy issues become an important problem.The rising federated learning provides us with a promising solution to this problem,which enables mobile devices to collaboratively learn a shared prediction model while keeping all the training data on the device,decoupling the ability to do machine learning from the need to store the data in the cloud.However,existing federated learningbased methods either do not provide privacy guarantees or have vulnerability in terms of privacy leakage.In this paper,we combine the techniques of data perturbation and model perturbation mechanisms and propose a privacy-preserving mobility prediction algorithm,where we add noise to the transmitted model and the raw data collaboratively to protect user privacy and keep the mobility prediction performance.Extensive experimental results show that our proposed method significantly outperforms the existing stateof-the-art mobility prediction method in terms of defensive performance against practical attacks while having comparable mobility prediction performance,demonstrating its effectiveness. 展开更多
关键词 federated learning mobility prediction PRIVACY
在线阅读 下载PDF
Photonics-assisted THz wireless communication enabled by wide-bandwidth packaged backilluminated modified uni-traveling-carrier photodiode
10
作者 Yuxin Tian Boyu Dong +11 位作者 Yaxuan Li Bing Xiong Junwen Zhang Changzheng Sun Zhibiao Hao Jian Wang Lai Wang Yanjun Han Hongtao Li Lin Gan Nan Chi Yi Luo 《Opto-Electronic Science》 2024年第7期20-29,共10页
This paper presents a wide-bandwidth back-illuminated modified uni-traveling-carrier photodiode(MUTC-PD)packaged with standard WR-5 rectangular waveguide for high-speed wireless communications.With optimized epitaxy s... This paper presents a wide-bandwidth back-illuminated modified uni-traveling-carrier photodiode(MUTC-PD)packaged with standard WR-5 rectangular waveguide for high-speed wireless communications.With optimized epitaxy structure and coplanar waveguide electrodes,the fabricated 4-μm-diameter PD exhibits ultra-flat frequency response and high saturation power.Integrated passive circuits including low-loss bias-tee and E-plane probe are designed to package the PD into a compact module with waveguide output.The packaged PD module has demonstrated a flat frequency response with fluctuations within±2.75 d B over a broadband of 140–220 GHz and a high saturated output power of-7.8 d Bm(166μW)at 140 GHz.For wireless communication applications,the packaged PD is used to implement 1-m free space transmission at carrier frequencies of 150.5 and 210.5 GHz,with transmission rates of 75 and 90 Gbps,respectively. 展开更多
关键词 modified uni-traveling-carrier photodiode integrated bias-tee E-plane probe flat frequency response high saturation power WR-5 output THz wireless communications
在线阅读 下载PDF
Topology Discovery Sub-Layer for Integrated Terrestrial-Satellite Network Routing Schemes 被引量:7
11
作者 Zengyin Yang Hewu Li +1 位作者 Qian Wu Jianping Wu 《China Communications》 SCIE CSCD 2018年第6期42-57,共16页
With the booming development of terrestrial network, scaling terrestrial network over satellite network to build Integrated Terrestrial-Satellite Network(ITSN) and meanwhile to provide the global Internet access, has ... With the booming development of terrestrial network, scaling terrestrial network over satellite network to build Integrated Terrestrial-Satellite Network(ITSN) and meanwhile to provide the global Internet access, has become ever more attractive. Naturally, the widely and successfully used terrestrial routing protocols are the promising protocols to integrate the terrestrial and satellite networks. However, the terrestrial routing protocols, which rely on propagating routing messages to discover New Network Topology(NNT) in the terrestrial network with rare topology changes, will suffer from overly numerous routing messages in satellite network whose topology frequently changes as satellites move. In this paper, a Topology Discovery Sub-layer for ITSN Routing Schemes(TDS-IRS) is firstly proposed to avoid the propagation of numerous routing messages by taking advantage of the movement predictability of satellite and the requirements of routing schemes to discover NNT in advance of topology change. Secondly, a Weighted Perfect Matching based Topology Discovery(WPM-TD) model is designed to conduct the NNT discovery on the ground. Thirdly, this paper builds a testbed with real network devices and meanwhile interconnect that testbed with real Internet, to validate that RS-TDS can discover NNT immediately with the less on-board overhead compared with optimized routing schemes. Finally, different network scenarios are applied to validate the WPM-TD, i.e., the core module of TDS-IRS. Extensive experiments show WPM-TD can work efficiently, avoiding the invalid NNT discovery and decreasing 20% ~ 57% of potential topology changes, which can also improve up to 47% ~ 105% of network throughput. 展开更多
关键词 integrated terrestrial-satellite net-work (itsn) routing scheme topology discovery topology discovery sub-hayer
在线阅读 下载PDF
Energy-Efficient UAV Trajectory Design for Backscatter Communication: A Deep Reinforcement Learning Approach 被引量:6
12
作者 Yiwen Nie Junhui Zhao +2 位作者 Jun Liu Jing Jiang Ruijin Ding 《China Communications》 SCIE CSCD 2020年第10期129-141,共13页
Recently,backscatter communication(BC)has been introduced as a green paradigm for Internet of Things(IoT).Meanwhile,unmanned aerial vehicles(UAVs)can serve as aerial base stations(BSs)to enhance the performance of BC ... Recently,backscatter communication(BC)has been introduced as a green paradigm for Internet of Things(IoT).Meanwhile,unmanned aerial vehicles(UAVs)can serve as aerial base stations(BSs)to enhance the performance of BC system thanks to their high mobility and flexibility.In this paper,we investigate the problem of energy efficiency(EE)for an energy-limited backscatter communication(BC)network,where backscatter devices(BDs)on the ground harvest energy from the wireless signal of a flying rotary-wing quadrotor.Specifically,we first reformulate the EE optimization problem as a Markov decision process(MDP)and then propose a deep reinforcement learning(DRL)algorithm to design the UAV trajectory with the constraints of the BD scheduling,the power reflection coefficients,the transmission power,and the fairness among BDs.Simulation results show the proposed DRL algorithm achieves close-to-optimal performance and significant EE gains compared to the benchmark schemes. 展开更多
关键词 unmanned aerial vehicle(UAV) trajectory design backscatter communication deep reinforcement learning ENERGY-EFFICIENT
在线阅读 下载PDF
A Better Zn-Ion Storage Device:Recent Progress for Zn-Ion Hybrid Supercapacitors 被引量:5
13
作者 Jialun Jin Xiangshun Geng +1 位作者 Qiang Chen Tian-Ling Ren 《Nano-Micro Letters》 SCIE EI CAS CSCD 2022年第4期158-206,共49页
As a new generation of Zn-ion storage systems,Zn-ion hybrid supercapacitors(ZHSCs)garner tremendous interests recently from researchers due to the perfect integration of batteries and supercapacitors.ZHSCs have excell... As a new generation of Zn-ion storage systems,Zn-ion hybrid supercapacitors(ZHSCs)garner tremendous interests recently from researchers due to the perfect integration of batteries and supercapacitors.ZHSCs have excellent integration of high energy density and power density,which seamlessly bridges the gap between batteries and supercapacitors,becoming one of the most viable future options for large-scale equipment and portable electronic devices.However,the currently reported two configurations of ZHSCs and corresponding energy storage mechanisms still lack systematic analyses.Herein,this review will be prudently organized from the perspectives of design strategies,electrode configurations,energy storage mechanisms,recent advances in electrode materials,electrolyte behaviors and further applications(micro or flexible devices)of ZHSCs.The synthesis processes and electrochemical properties of well-designed Zn anodes,capacitor-type electrodes and novel Zn-ion battery-type cathodes are comprehensively discussed.Finally,a brief summary and outlook for the further development of ZHSCs are presented as well.This review will provide timely access for researchers to the recent works regarding ZHSCs. 展开更多
关键词 Zn-ion storage systems Zn-ion hybrid supercapacitors Carbon electrodes Zinc anodes Electrolytes
在线阅读 下载PDF
Soft Electronics for Health Monitoring Assisted by Machine Learning 被引量:5
14
作者 Yancong Qiao Jinan Luo +11 位作者 Tianrui Cui Haidong Liu Hao Tang Yingfen Zeng Chang Liu Yuanfang Li Jinming Jian Jingzhi Wu He Tian Yi Yang Tian-Ling Ren Jianhua Zhou 《Nano-Micro Letters》 SCIE EI CAS CSCD 2023年第5期83-168,共86页
Due to the development of the novel materials,the past two decades have witnessed the rapid advances of soft electronics.The soft electronics have huge potential in the physical sign monitoring and health care.One of ... Due to the development of the novel materials,the past two decades have witnessed the rapid advances of soft electronics.The soft electronics have huge potential in the physical sign monitoring and health care.One of the important advantages of soft electronics is forming good interface with skin,which can increase the user scale and improve the signal quality.Therefore,it is easy to build the specific dataset,which is important to improve the performance of machine learning algorithm.At the same time,with the assistance of machine learning algorithm,the soft electronics have become more and more intelligent to realize real-time analysis and diagnosis.The soft electronics and machining learning algorithms complement each other very well.It is indubitable that the soft electronics will bring us to a healthier and more intelligent world in the near future.Therefore,in this review,we will give a careful introduction about the new soft material,physiological signal detected by soft devices,and the soft devices assisted by machine learning algorithm.Some soft materials will be discussed such as two-dimensional material,carbon nanotube,nanowire,nanomesh,and hydrogel.Then,soft sensors will be discussed according to the physiological signal types(pulse,respiration,human motion,intraocular pressure,phonation,etc.).After that,the soft electronics assisted by various algorithms will be reviewed,including some classical algorithms and powerful neural network algorithms.Especially,the soft device assisted by neural network will be introduced carefully.Finally,the outlook,challenge,and conclusion of soft system powered by machine learning algorithm will be discussed. 展开更多
关键词 Soft electronics Machine learning algorithm Physiological signal monitoring Soft materials
在线阅读 下载PDF
A Frequency Domain Based Signal Combining Method for Distributed Antenna Arraying 被引量:2
15
作者 Chaowei Duan Yafeng Zhan Qian Kong 《China Communications》 SCIE CSCD 2019年第8期176-184,共9页
Distributed antenna arraying is a promising technology for weak signal reception. The received signals from different antennas are aligned and combined to improve the receiving signal-to-noise ratio(SNR). However, the... Distributed antenna arraying is a promising technology for weak signal reception. The received signals from different antennas are aligned and combined to improve the receiving signal-to-noise ratio(SNR). However, the combining performance is serious degraded by the difference of sampling frequency between antennas. In this paper, a frequency domain based signal combining method is proposed to solve this problem. The unaligned sampled data in time domain of the received signals are transformed to frequency domain using fast Fourier transform(FFT). The received signals can be aligned in frequency domain when their spectrum resolutions are the same. Therefore the received signals with the same total sampling time can be aligned and combined in frequency domain and then the combined signal is recovered using inverse fast Fourier transform(IFFT). Numerical simulations with two typical modulation types, i.e., PSK and PCM/BPSK/PM, prove the validity and robustness of this method. 展开更多
关键词 WEAK SIGNAL RECEPTION DISTRIBUTED antenna arraying SIGNAL combining fast FOURIER TRANSFORM
在线阅读 下载PDF
Robust Beamforming for Secured Wireless Power Transfer in MIMO Magnetic Resonant Coupling System:A Probabilistic Approach 被引量:2
16
作者 Ling Xing Kaikai Deng Feifei Gao 《China Communications》 SCIE CSCD 2019年第1期97-107,共11页
Wireless power transfer(WPT) to support mobile and portable devices is an emerging wireless technique.Among all kinds of approaches,magnetic resonance coupling(MRC) is an excellent one for mid-range WPT,which provides... Wireless power transfer(WPT) to support mobile and portable devices is an emerging wireless technique.Among all kinds of approaches,magnetic resonance coupling(MRC) is an excellent one for mid-range WPT,which provides better mobility,flexibility,and convenience due to its simplicity in hardware implementation and longer transmission distances.In this paper,we consider an MRCWPT system with multiple power transmitters,one intended power receiver and multiple unintended power receivers.We investigate the probabilistic robust beamforming designs and provide efficient algorithms to achieve the local optimums under two different criteria,i.e.,total source power minimization problem and min-max unintended receiving power restriction problem.As the problems are quite typical in robust design situations,our proposed robust beamformers can be conveniently applied to other probabilistic robust design problems,thus reduce the complexity as well as improve the beamforming performance.Numerical results demonstrate that the proposed algorithms can significantly improve the performance as well as the robustness of the WPT system. 展开更多
关键词 MAGNETIC RESONANCE coupling wireless POWER transfer BEAMFORMING probabilistic robustness POWER security
在线阅读 下载PDF
PerfMon: Measuring Application-Level Performance in a Large-Scale Campus Wireless Network 被引量:2
17
作者 Weizhen Dang Tao Yu +3 位作者 Haibo Wang Jing’An Xue Fenghua Li Jilong Wang 《China Communications》 SCIE CSCD 2023年第3期316-335,共20页
WiFi has become one of the most popular ways to access the Internet.However,in large-scale campus wireless networks,it is challenging for network administrators to provide optimized access quality without knowledge on... WiFi has become one of the most popular ways to access the Internet.However,in large-scale campus wireless networks,it is challenging for network administrators to provide optimized access quality without knowledge on fine-grained traffic characteristics and real network performance.In this paper,we implement PerfMon,a network performance measurement and diagnosis system,which integrates collected multi-source datasets and analysis methods.Based on PerfMon,we first conduct a comprehensive measurement on application-level traffic patterns and behaviors from multiple dimensions in the wireless network of T university(TWLAN),which is one of the largest campus wireless networks.Then we systematically study the application-level network performance.We observe that the application-level traffic behaviors and performance vary greatly across different locations and device types.The performance is far from satisfactory in some cases.To diagnose these problems,we distinguish locations and device types,and further locate the most crucial factors that affect the performance.The results of case studies show that the influential factors can effectively characterize performance changes and explain for performance degradation. 展开更多
关键词 WIFI traffic patterns network manage-ment performance measurement network diagnosis
在线阅读 下载PDF
Cell Breathing Scheme for Mega-Constellation Satellite Networks 被引量:1
18
作者 LIN Zitong LI Hewu LIU Jun 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2022年第2期152-163,共12页
Low earth orbit(LEO)mega-constellations can provide global low-latency high bandwidth coverage compared to the terrestrial network.The time-varying topology of satellite networks and the uneven traffic distribution le... Low earth orbit(LEO)mega-constellations can provide global low-latency high bandwidth coverage compared to the terrestrial network.The time-varying topology of satellite networks and the uneven traffic distribution lead to the mismatch between satellites and users,resulting in the waste of satellite resources and the degradation of user performance.Through negotiation with neighbors,the traditional terrestrial cell breathing continuously converges to the optimal cell size in the face of user tides,but this method is difficult to converge timely when facing rapid and extreme flow changes caused by the rapid movement of satellites.This paper presents a fast adaptive cell breathing scheme(Fa B)through sub-block division and satellite cell initialization and adjustment.Fa B divides the ground into sub-blocks according to the user density.When the satellite moves in the same sub-block,the step size of breathing is adjusted according to the cell size difference between the previous satellite and the current satellite.When the satellite switches between different sub-blocks,the initial value of the cell is determined according to the density of the new sub-block.In addition to negotiating with neighboring satellites,this scheme also introduces location information to directly adjust the parameters of cell breathing and decrease the time of cell breathing convergence.From the real constellation data-driven simulation,we conclude that Fa B can quickly adjust the size of the cell with the location changing,and the utilization rate is increased by 2.66 times compared to the method with no cell breathing,and by2.37 times compared to the method with cell breathing without location information. 展开更多
关键词 satellite networks cell breathing mega-constellation block division
在线阅读 下载PDF
Three-dimensional vertical ZnO transistors with suspended top electrodes fabricated by focused ion beam technology
19
作者 Chi Sun Linyuan Zhao +4 位作者 Tingting Hao Renrong Liang Haitao Ye Junjie Li Changzhi Gu 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第1期492-496,共5页
Three-dimensional(3D)vertical architecture transistors represent an important technological pursuit,which have distinct advantages in device integration density,operation speed,and power consumption.However,the fabric... Three-dimensional(3D)vertical architecture transistors represent an important technological pursuit,which have distinct advantages in device integration density,operation speed,and power consumption.However,the fabrication processes of such 3D devices are complex,especially in the interconnection of electrodes.In this paper,we present a novel method which combines suspended electrodes and focused ion beam(FIB)technology to greatly simplify the electrodes interconnection in 3D devices.Based on this method,we fabricate 3D vertical core-double shell structure transistors with ZnO channel and Al_(2)O_(3) gate-oxide both grown by atomic layer deposition.Suspended top electrodes of vertical architecture could be directly connected to planar electrodes by FIB deposited Pt nanowires,which avoid cumbersome steps in the traditional 3D structure fabrication technology.Both single pillar and arrays devices show well behaved transfer characteristics with an Ion/Ioff current ratio greater than 106 and a low threshold voltage around 0 V.The ON-current of the 2×2 pillars vertical channel transistor was 1.2μA at the gate voltage of 3 V and drain voltage of 2 V,which can be also improved by increasing the number of pillars.Our method for fabricating vertical architecture transistors can be promising for device applications with high integration density and low power consumption. 展开更多
关键词 three-dimensional(3D)vertical ZnO transistor focused ion beam(FIB) suspended electrodes the electrical inter-connection in 3D devices
在线阅读 下载PDF
Study on the Two-Sides Matching between Multiple Rovers and Multiple Orbiters in Mars Relay Communications
20
作者 Peng Wan Yafeng Zhan 《China Communications》 SCIE CSCD 2020年第7期80-93,共14页
In Mars relay communications,if multiple rovers and multiple orbiters are visible with each other at the same time in certain contact,there are not only issues concerned with the multiple rovers’access to single orbi... In Mars relay communications,if multiple rovers and multiple orbiters are visible with each other at the same time in certain contact,there are not only issues concerned with the multiple rovers’access to single orbiter,but also the issues concerned with the optimal access orbiter selection for each rover,which is a complex multi-objective decision-making problem relating to the resource allocation optimizations in deep-space networks.In this paper,the two-sides matching between multiple rovers and multiple orbiters in Mars relay communications is proposed based on the access preferences,taking the two-sides combined fitness of preferences and the single-side evaluation equilibrium as the optimization objectives,which utilizes the parallel capsule operations architecture encapsulated with several one-to-many two-sides matching algorithms to obtain stable multiple access matching results.Simulation results show that,our method performs better than the CCSDS Proximity-1 protocols,and could achieve the effective utilization of deep space communication network resources. 展开更多
关键词 MATCHING utilize concerned
在线阅读 下载PDF
上一页 1 2 下一页 到第
使用帮助 返回顶部