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Resource and trajectory optimization in UAV-powered wireless communication system

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Science China(information Sciences) 2021年第4期64卷 54-67页

作者： Weidang LU Peiyuan SI Fangwei LU Bo LI Zilong LIU Su HU Yi GONG College of Information Engineering Zhejiang University of Technology School of Information Science and Engineering Harbin Institute of Technology School of Computer Science and Electronics Engineering University of Essex National Key Laboratory on Communications University of Electronic Science and Technology of China University Key Laboratory of Advanced Wireless Communications of Guangdong Province Southern University of Science and Technology

The unmanned aerial vehicle(UAV) is a promising enabler of Internet of Things(IoT) owing to its highly flexible features. Combined with wireless power transfer(WPT) techniques, a UAV can provide energy for IoT nodes, which can extend the lifetime of energy constrained communication systems. This paper studies resource and trajectory optimization in UAV-powered wireless communication systems, which consists of two UAVs and two ground nodes(GNs). The system works in a way that the two UAVs alternately charge the two GNs through wireless power transfer and two GNs also alternately send their information to the corresponding UAV with the harvested energy, which can effectively reduce the interference while receiving the information of GNs. Aiming to maximize the minimum throughput of two GNs, wireless resource and UAVs' trajectories are jointly optimized with the constraints of UAV collision avoidance, flying speed, and transmit power. Successive convex programming(SCP) and block coordinate descent(BCD) are utilized to solve the optimization problem. Simulation results show that the proposed scheme achieves larger minimum throughput than the benchmark scheme.

关键词： UAV wireless power transfer trajectory optimization resource allocation

A new quantum machine learning algorithm: split hidden quantum Markov model inspired by quantum conditional master equation

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arXiv 2023年

作者： Li, Xiao-Yu Zhu, Qin-Sheng Hu, Yong Wu, Hao Yang, Guo-Wu Yu, Lian-Hui Chen, Geng School of Information and Software Engineering University of Electronic Science and Technology of China Chengdu610054 China School of Physics University of Electronic Science and Technology of China Chengdu610054 China Advanced Cryptography and System Security Key Laboratory of Sichuan Province Chengdu610103 China Institute of Electronics and Information Industry Technology of Kash Kash 844000 China School of Computer Science and Engineering University of Electronic Science and Technology of China Chengdu610054 China

The Hidden Quantum Markov Model (HQMM) has significant potential for analyzing time-series data and studying stochastic processes in the quantum domain as an upgrading option with potential advantages over classical Markov models. In this paper, we introduced the split HQMM (SHQMM) for implementing the hidden quantum Markov process, utilizing the conditional master equation with a fine balance condition to demonstrate the interconnections among the internal states of the quantum system. The experimental results suggest that our model outperforms previous models in terms of scope of applications and robustness. Additionally, we establish a new learning algorithm to solve parameters in HQMM by relating the quantum conditional master equation to the HQMM. Finally, our study provides clear evidence that the quantum transport system can be considered a physical representation of HQMM. The SHQMM with accompanying algorithms present a novel method to analyze quantum systems and time series grounded in physical implementation. © 2023, CC BY-NC-SA.

关键词： Stochastic systems

Statistical Analysis of Intrinsic High-Frequency Characteristic Fluctuation of Emerging Silicon Gate-All-Around Nanosheet (NS) MOSFETs at Sub-3-nm Nodes

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Statistical Analysis of Intrinsic High-Frequency Characteris...

IEEE Electron Devices technology and Manufacturing Conference (EDTM)

作者： Sekhar Reddy Kola Yiming Li Min-Hui Chuang Kazuhiko Endo Seiji Samukawa Parallel and Scientific Computing Laboratory Electrical Engineering and Computer Science International Graduate Program Institute of Communications Engineering Department of Electronics and Electrical Engineering Institute of Biomedical Engineering Center for mm Wave Smart Radar System and Technologies National Yang Ming Chiao Tung University Hsinchu Taiwan Institute of Fluid Science Tohoku University 2-1-1 Katahira Aoba-ku Sendai Japan National Institute of Advanced Industrial Science and Technology Tsukuba Japan

In recent years, the GAA NS Si MOSFET has been explored as a leading technology. However, the intrinsic parameters of GAA NS Si MOSFETs are affected to varying degrees by various fluctuation sources, Statistically independent and identically distributed $(iid)$ assumptions on the aforementioned random variables overestimate the variability of high-frequency characteristics, compared with considering all fluctuation factors simultaneously. Notably, the random nanosized metal grains dominates the variations of voltage gain, cut-off frequency, and 3dB frequency because the random work functions strongly alter the channel surface potential.

关键词： MOSFET Fluctuations Statistical analysis Gallium arsenide Cutoff frequency Metals Logic gates

Emerging 2D Metal Oxides: From Synthesis to Device Integration

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advanced Materials 2023年第21期35卷 2370148-2370148页

作者： Zhou, Kui Shang, Gang Hsu, Hsiao-Hsuan Han, Su-Ting Roy, Vellaisamy A. L. Zhou, Ye Institute for Advanced Study Shenzhen University Shenzhen518060 China College of Electronics and Information Engineering Shenzhen University Shenzhen518060 China Department of Materials and Mineral Resources Engineering National Taipei University of Technology Taipei10608 Taiwan James Watt School of Engineering University of Glasgow GlasgowG12 8QQ United Kingdom

2D metal oxides have aroused increasing attention in the field of electronics and optoelectronics due to their intriguing physical properties. In this review, an overview of recent advances on synthesis of 2D metal oxides and their electronic applications is presented. First, the tunable physical properties of 2D metal oxides that relate to the structure (various oxidation-state forms, polymorphism, etc.), crystallinity and defects (anisotropy, point defects, and grain boundary), and thickness (quantum confinement effect, interfacial effect, etc.) are discussed. Then, advanced synthesis methods for 2D metal oxides besides mechanical exfoliation are introduced and classified into solution process, vapor-phase deposition, and native oxidation on a metal source. Later, the various roles of 2D metal oxides in widespread applications, i.e., transistors, inverters, photodetectors, piezotronics, memristors, and potential applications (solar cell, spintronics, and superconducting devices) are discussed. Finally, an outlook of existing challenges and future opportunities in 2D metal oxides is proposed. © 2023 Wiley-VCH GmbH.

关键词： Photodetectors

Image-based Freeform Handwriting Authentication with Energy-oriented Self-Supervised Learning

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arXiv 2024年

作者： Wang, Jingyao Mou, Luntian Zheng, Changwen Gao, Wen The University of Chinese Academy of Sciences Beijing100049 China The National Key Laboratory of Space Integrated Information System Institute of Software Chinese Academy of Sciences Beijing100086 China Beijing Institute of Artiicial Intelligence Faculty of Information Beijing University of Technology Beijing100124 China Beijing Key Laboratory of Multimedia and Intelligent Software Technology Beijing100124 China The School of Electronics Engineering and Computer Science Peking University Beijing100871 China

Freeform handwriting authentication verifies a person’s identity from their writing style and habits in messy handwriting data. This technique has gained widespread attention in recent years as a valuable tool for various fields, e.g., fraud prevention and cultural heritage protection. However, it still remains a challenging task in reality due to three reasons: (i) severe damage, (ii) complex high-dimensional features, and (iii) lack of supervision. To address these issues, we propose SherlockNet, an energy-oriented two-branch contrastive self-supervised learning framework for robust and fast freeform handwriting authentication. It consists of four stages: (i) pre-processing: converting manuscripts into energy distributions using a novel plug-and-play energy-oriented operator to eliminate the influence of noise;(ii) generalized pre-training: learning general representation through two-branch momentum-based adaptive contrastive learning with the energy distributions, which handles the high-dimensional features and spatial dependencies of handwriting;(iii) personalized fine-tuning: calibrating the learned knowledge using a small amount of labeled data from downstream tasks;and (iv) practical application: identifying individual handwriting from scrambled, missing, or forged data efficiently and conveniently. Considering the practicality, we construct EN-HA, a novel dataset that simulates data forgery and severe damage in real applications. Finally, we conduct extensive experiments on six benchmark datasets including our EN-HA, and the results prove the robustness and efficiency of SherlockNet. We will release our code and dataset at https://***/WangJingyao07/SherlockNet. Copyright © 2024, The Authors. All rights reserved.

关键词： Self-supervised learning

Highly efficient nonuniform finite difference method for three-dimensional electrically stimulated liquid crystal photonic devices

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Photonics Research 2024年第4期12卷 865-875页

作者： ZHENGHAO GUO MENGJUN LIU ZIJIA CHEN RUIZHI YANG PEIYUN LI HAIXIA DA DONG YUAN GUOFU ZHOU LINGLING SHUI HUAPENG YE Guangdong Provincial Key Laboratory of Optical Information Materials and Technology&Institute of Electronic Paper Displays South China Academy of Advanced OptoelectronicsSouth China Normal UniversityGuangzhou 510006China SCNU-TUE Joint Lab of Device Integrated Responsive Materials(DIRM) National Center for International Research on Green OptoelectronicsSouth China Normal UniversityGuangzhou 510006China Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices School of Information and Optoelectronic Science and EngineeringSouth China Normal UniversityGuangzhou 510006China Joint Laboratory of Optofluidic Technology and Systems National Center for International Research on Green OptoelectronicsSouth China Academy of Advanced OptoelectronicsSouth China Normal UniversityGuangzhou 510006China College of Electronic and Optical Engineering&College of Microelectronics Nanjing University of Posts and TelecommunicationsNanjing 210046China Key Laboratory of Radio Frequency and Micro-Nano Electronics of Jiangsu Province Nanjing 210023China

Liquid crystal(LC)photonic devices have attracted intensive attention in recent decades,due to the merits of tunability,cost-effectiveness,and high ***,the precise and efficient simulation of large-scale three-dimensional electrically stimulated LC photonic devices remains challenging and resource *** we report a straightforward nonuniform finite difference method(NFDM)for efficiently simulating largescale LC photonic devices by employing a spatially nonuniform mesh grid.

关键词： nonuniform crystal finite

Refracting Reconfigurable Intelligent Surface Assisted URLLC for Millimeter Wave High-Speed Train Communication Coverage Enhancement

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arXiv 2024年

作者： Liu, Changzhu He, Ruisi Niu, Yong Mao, Shiwen Ai, Bo Chen, Ruifeng The School of Electronics and Information Engineering The Frontiers Science Center for Smart High-speed Railway System Beijing Jiaotong University Beijing100044 China The School of Electronics and Information Engineering Beijing Jiaotong University Beijing100044 China The National Mobile Communications Research Laboratory Southeast University Nanjing211189 China The Department of Electrical and Computer Engineering Auburn University AuburnAL36849-5201 United States The Institute of Computing Technology China Academy of Railway Sciences Corporation Limited Beijing100081 China

High-speed train (HST) has garnered significant attention from both academia and industry due to the rapid development of railways worldwide. Millimeter wave (mmWave) communication, known for its large bandwidth is an effective way to address performance bottlenecks in cellular network based HST wireless communication systems. However, mmWave signals suffer from significant path loss when traversing carriage, posing substantial challenges to cellular networks. To address this issue, reconfigurable intelligent surfaces (RIS) have gained considerable interest for its ability to enhance cell coverage by reflecting signals toward receiver. Ensuring communication reliability, a core performance indicators of ultra-reliable and low-latency communications (URLLC) in fifth-generation systems, is crucial for providing steady and reliable data transmissions along railways, particularly for delivering safety and control messages and monitoring HST signaling information. In this paper, we investigate a refracting RIS-assisted multi-user multiple-input single-output URLLC system in mmWave HST communications. We propose a sum rate maximization problem, subject to base station beamforming constraint, as well as refracting RIS discrete phase shifts and reliability constraints. To solve this optimization problem, we design a joint optimization algorithm based on alternating optimization method. This involves decoupling the original optimization problem into active beamforming design and packet error probability optimization subproblem, and discrete phase shift design subproblems. These subproblems are addressed exploiting Lagrangian dual method and the local search method, respectively. Simulation results demonstrate the fast convergence of the proposed algorithm and highlight the benefits of refracting RIS adoption for sum rate improvement in mmWave HST networks. Copyright © 2024, The Authors. All rights reserved.

关键词： Mobile telecommunication systems

A Sub-aF Super-High-Resolution Capacitance-to-Digital Converter with a Bandpass ΔΣ ADC

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A Sub-aF Super-High-Resolution Capacitance-to-Digital Conver...

IEEE International Symposium on Circuits and systems (ISCAS)

作者： Yoontae Jung Soon-Jae Kweon Hyuntak Jeon Jeongeun Lee Youngin Kim Sein Oh Jimin Koo Minkyu Je School of Electrical Engineering Korea Advanced Institute of Science and Technology (KAIST) Daejeon South Korea Division of Engineering New York University Abu Dhabi Abu Dhabi United Arab Emirates School of Electronics and Electrical Engineering Chungbuk National University Cheongju South Korea Samsung Electronics Company Ltd. Hwaseong South Korea Department of Information Technology and Electrical Engineering ETH Zürich Switzerland

A super-high-resolution capacitance-to-digital converter (CDC) capable of reaching sub-aF capacitance resolution has been proposed. The CDC employs a continuous-time (CT) low-noise capacitance-to-voltage converter (CVC) followed by a high linearity bandpass $\Delta\Sigma$ ADC $(\text{BP}-\Delta\Sigma \mathrm{M})$ without frequency demodulation. By avoiding demodulation and utilizing a narrow-band sensing technique, the proposed CDC achieves a sub-aF capacitance resolution while expanding the input capacitance range through a coarse C-DAC calibration loop. The proposed circuit has been implemented in a $0.35-\mu \mathrm{m}$ CMOS process with a 3.3 V power supply voltage. The CDC shows a capacitance resolution of 0.98 $\text{aF}_{\text{rms}}$ , with a capacitance range of 3.1 pF, while consuming 4.16 mW.

关键词：

Pre-Equalization Aided Grant-Free Massive Access in Massive MIMO system

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arXiv 2025年

作者： Wang, Yueqing Mei, Yikun Gao, Zhen Wan, Ziwei Ning, Boyu Mi, De Muhaidat, Sami School of Information and Electronics Beijing Institute of Technology Beijing100081 China MIIT Key Laboratory of Complex-Field Intelligent Sensing Beijing Institute of Technology Beijing100081 China Jiaxing314019 China Advanced Technology Research Institute Beijing Institute of Technology Jinan250307 China National Key Laboratory of Wireless Communications University of Electronic Science and Technology of China Chengdu611731 China School of Computing and Digital Technology Birmingham City University BirminghamB55JU United Kingdom KU 6G Research Center Department of Computer and Information Engineering Khalifa University Abu Dhabi United Arab Emirates

The spatial diversity and multiplexing advantages of massive multi-input-multi-output (mMIMO) can significantly improve the capacity of massive non-orthogonal multiple access (NOMA) in machine type communications. However, state-of-the-art grant-free massive NOMA schemes for mMIMO systems require accurate estimation of random access channels to perform activity detection and the following coherent data demodulation, which suffers from excessive pilot overhead and access latency. To address this, we propose a pre-equalization aided grant-free massive access scheme for mMIMO systems, where an iterative detection scheme is conceived. Specifically, the base station (BS) firstly activates one of its antennas (i.e., beacon antenna) to broadcast a beacon signal, which facilitates the user equipment (UEs) to perform downlink channel estimation and pre-equalize the uplink random access signal with respect to the channels associated with the beacon antenna. During the uplink transmission stage, the BS detects UEs’ activity and data by using the proposed iterative detection algorithm, which consists of three modules: coarse data detection (DD), data-aided channel estimation (CE), and fine DD. In the proposed algorithm, the joint activity and DD is firstly performed based on the signals received by the beacon antenna. Subsequently, the DD is further refined by iteratively performing data-aided CE module and fine DD module using signals received by all BS antennas. Our simulation results demonstrate that the proposed scheme outperforms state-of-the-art mMIMO-based grant-free massive NOMA schemes with the same access latency. Simulation codes are provided to reproduce the results in this article: https://***/owenwang517/tvt-2025. Copyright © 2025, The Authors. All rights reserved.

关键词： Channel estimation