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Differentially Coplanar-Fed Antenna for Millimeter-Wave Applications based on Integrated Substrate Gap Waveguide 9

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Differentially Coplanar-Fed Antenna for Millimeter-Wave Appl...

9th IEEE Asia-Pacific Conference on Antennas and Propagation, APCAP 2020

作者： Lu, Lizhu Shen, Dongya Yuan, Hong Zhang, Xiupu Yunnan University Yunnan Provincial Engineering Laboratory of Cloud Wireless Access and Heterogeneous Networks Kunming650500 China Concordia University IPhotonics Labs Department of Electrical and Computer Engineering MontrealQCH3G1M8 Canada

ISBN: (纸本)9781728198057

In this letter, a differentially coplanar-fed antenna using integrated substrate gap waveguide (ISGW) is proposed for millimeter-wave applications, which has high gain and low cross polarization. The antenna consists of the differential power divider and radiation patch, and the power divider is deployed to excite the differential feeding antenna. The differential power divider is designed using rectangular-shaped coupling slot to achieve a stable 180° phase imbalance and 15% fractional operating bandwidth. The differentially coplanar-fed cross-shaped patch antenna has high gain and good radiation patterns. A fractional bandwidth of about 8.3% at the center frequency of 24 GHz and a peak gain of 10 dBi are obtained. © 2020 IEEE.

关键词： Microstrip antennas

Real-time and ultrafast optical pulse quantization based on slicing the supercontinuum

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Chinese Optics Letters 2021年第8期19卷 69-74页

作者： Ya Guo Qiang Cai Zhiwei Jia Bingjie Xu Zhensen Gao Qianwu Zhang Ruonan Zhang Adonis Bogris K.Alan Shore Yuncai Wang Pu Li Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of EducationTaiyuan University of TechnologyTaiyuan 030024China School of Information Engineering Guangdong University of TechnologyGuangzhou 510006China Key Laboratory of Specialty Fiber Optics and Optical Access Networks Shanghai UniversityShanghai 200444China School of Electronics and Information Northwestern Polytechnical UniversityXi’an 710072China Science and Technology on Communication Security Laboratory Institute of Southwestern CommunicationChengdu 610041China Department of Informatics and Computer Engineering University of West AtticaAthens 12243Greece School of Electronic Engineering Bangor UniversityWales LL571UTUnited Kingdom

All-optical analog-to-digital conversion is a paramount issue in modern science. How to implement real-time and ultrafast quantization to optical pulses with different intensities in an all-optical domain is a central problem. Here, we report a realtime demonstration of an all-optical quantization scheme based on slicing the supercontinuum in a nonlinear fiber. In comparison with previous schemes through off-line analysis of the power of different optical spectral components in the supercontinuum, this, to the best of our knowledge, is the first demonstration of such functionality online in the time ***, the extinction ratio among the quantized outputs can exceed 10 d B, which further confirms the feasibility of the proposed quantization scheme. The current 3 bit resolution in the proof-of-principle experiment is limited by the current experimental condition, but it can be expected to be greatly enhanced through improving both the spectral width of the generated supercontinuum and the number of filtering channels used.

关键词： all-optical analog-to-digital conversion photonic quantization all-optical signal processing supercontinuum generation

RadioGAT: A Joint Model-based and Data-driven Framework for Multi-band Radiomap Reconstruction via Graph Attention networks

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arXiv 2024年

作者： Li, Xiaojie Zhang, Songyang Li, Hang Li, Xiaoyang Xu, Lexi Xu, Haigao Mei, Hui Zhu, Guangxu Qi, Nan Xiao, Ming Shenzhen Research Institute of Big Data The Chinese University of Hong Kong-Shenzhen Guangdong China College of Physics Nanjing University of Aeronautics and Astronautics Nanjing210016 China Department of Electrical and Computer Engineering University of Louisiana at Lafayette LafayetteLA70503 United States Research Institute China United Network Communications Corporation Beijing100048 China China Mobile Communications Group Jiangxi Co. Ltd 330038 China Key Laboratory of Dynamic Cognitive System of Electromagnetic Spectrum Space Nanjing University of Aeronautics and Astronautics Nanjing210016 China State Key Laboratory of Integrated Services Networks Xidian University Xi'An710071 China Department of Information Science and Engineering School of Electrical Engineering of KTH Royal Institute of Technology Stockholm Sweden

Multi-band radiomap reconstruction (MB-RMR) is a key component in wireless communications for tasks such as spectrum management and network planning. However, traditional machine-learning-based MB-RMR methods, which rely heavily on simulated data or complete structured ground truth, face significant deployment challenges. These challenges stem from the differences between simulated and actual data, as well as the scarcity of real-world measurements. To address these challenges, our study presents RadioGAT, a novel framework based on Graph Attention Network (GAT) tailored for MBRMR within a single area, eliminating the need for multiregion datasets. RadioGAT innovatively merges model-based spatial-spectral correlation encoding with data-driven radiomap generalization, thus minimizing the reliance on extensive data sources. The framework begins by transforming sparse multiband data into a graph structure through an innovative encoding strategy that leverages radio propagation models to capture the spatial-spectral correlation inherent in the data. This graph-based representation not only simplifies data handling but also enables tailored label sampling during training, significantly enhancing the framework's adaptability for deployment. Subsequently, The GAT is employed to generalize the radiomap information across various frequency bands. Extensive experiments using raytracing datasets based on real-world environments have demonstrated RadioGAT's enhanced accuracy in supervised learning settings and its robustness in semi-supervised scenarios. These results underscore RadioGAT's effectiveness and practicality for MBRMR in environments with limited data availability. Copyright © 2024, The Authors. All rights reserved.

关键词： Encoding (symbols)

Intelligent Reflecting Surface Enabled Sensing: Cramér-Rao Lower Bound Optimization

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arXiv 2022年

作者： Song, Xianxin Xu, Jie Liu, Fan Han, Tony Xiao Eldar, Yonina C. School of Science and Engineering Future Network of Intelligence Institute Guangdong Provincial Key Laboratory of Future Networks of Intelligence The Chinese University of Hong Kong Shenzhen China Department of Electrical and Electronic Engineering Southern University of Science and Technology China Wireless Technology Lab Laboratories 2012 Huawei China Faculty of Mathematics and Computer Science Weizmann Institute of Science Israel

This paper investigates intelligent reflecting surface (IRS) enabled non-line-of-sight (NLoS) wireless sensing, in which an IRS is deployed to assist an access point (AP) to sense a target in its NLoS region. It is assumed that the AP is equipped with multiple antennas and the IRS is equipped with a uniform linear array. The AP aims to estimate the target's direction-of-arrival (DoA) with respect to the IRS, based on the echo signals from the AP-IRS-target-IRS-AP link. Under this setup, we jointly design the transmit beamforming at the AP and the reflective beamforming at the IRS to minimize the Cramér-Rao lower bound (CRLB) on estimation error. Towards this end, we first obtain the CRLB expression for estimating the DoA in closed form. Next, we optimize the joint beamforming design to minimize the CRLB, via alternating optimization, semi-definite relaxation, and successive convex approximation. Numerical results show that the proposed design based on CRLB minimization achieves improved sensing performance in terms of mean squared error, as compared to the traditional schemes with signal-to-noise ratio maximization and separate beamforming. Copyright © 2022, The Authors. All rights reserved.

关键词： Beamforming

A lightweight identity authentication scheme for UAV and road base stations 2020

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A lightweight identity authentication scheme for UAV and roa...

Proceedings of the 2020 International Conference on Cyberspace Innovation of Advanced Technologies

作者： Yinyin Li Xiaoyu Du Sufang Zhou International Joint Research Laboratory for Cooperative Vehicular Networks of Henan Kaifeng Henan University Kaifeng Henan School of Computer and Information Engineering Henan University Kaifeng Henan Institute of Data and Knowledge Engineering Henan University Kaifeng Henan

ISBN: (纸本)9781450387828

At present, unmanned aerial vehicles (UAVs) have been widely used in civilian fields (such as smart cities). However, the external environment of the UAV network is complex and computing resources are limited, so it is vulnerable to serious security threats, such as replay attacks, forgery attacks, man-in-the-middle attacks. Seriously, it will cause great damage to the work of the UAV in smart cities. Aiming at the problem of transmission instruction data leakage caused by malicious UAV in communication between road base stations and UAVs, this paper proposes a lightweight identity authentication scheme based on elliptic curve cryptography (ECC). The purpose is to ensure the identity authentication of the UAV and the road base station, to ensure that the mission instructions received by the UAV are authentic and reliable, and to ensure the privacy of the UAV's identity information. The algorithm mainly includes the system initialization phase, initializing the UAV and road base station, and the identity authentication phase. Compared with the traditional identity authentication method, this method has the characteristics of low computational cost, short key and high security, and is more suitable for UAV communication.

关键词： Identity authentication Elliptic curve cryptography (ECC) UAV and road base stations

Resource Allocation for Text Semantic Communications

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arXiv 2022年

作者： Yan, Lei Qin, Zhijin Zhang, Rui Li, Yongzhao Li, Geoffrey Ye The State Key Laboratory of Integrated Services Networks Xidian University Xi’an710071 China The School of Electronic Engineering and Computer Science Queen Mary University of London LondonE1 4NS United Kingdom School of Electrical and Electronic Engineering Imperial College London LondonSW7 2AZ United Kingdom

Semantic communications have shown its great potential to improve the transmission reliability, especially in the low signal-to-noise regime. However, resource allocation for semantic communications still remains unexplored, which is a critical issue in guaranteeing the semantic transmission reliability and the communication efficiency. To fill this gap, we investigate the spectral efficiency in the semantic domain and rethink the semantic-aware resource allocation issue. Specifically, taking text semantic communication as an example, the semantic spectral efficiency (S-SE) is defined for the first time, and is used to optimize resource allocation in terms of channel assignment and the number of transmitted semantic symbols. Additionally, for fair comparison of semantic and conventional communication systems, a transform method is developed to convert the conventional bit-based spectral efficiency to the S-SE. Simulation results demonstrate the validity and feasibility of the proposed resource allocation method, as well as the superiority of semantic communications in terms of the S-SE. Copyright © 2022, The Authors. All rights reserved.

关键词： Semantics

Joint Power Allocation and Decoding Order Selection for NOMA Systems: Outage-Optimal Strategies

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arXiv 2022年

作者： Yang, Mengqi Chen, Jian Ding, Zhiguo Liu, Yuanwei Lv, Lu Yang, Long The State Key Laboratory of Integrated Services Networks Xidian University Xi’an710071 China The School of Electrical and Electronic Engineering The University of Manchester ManchesterM13 9PL United Kingdom The School of Electronic Engineering and Computer Science Queen Mary University of London LondonE1 4NS United Kingdom

We investigate joint power allocation and decoding order selection (PA-DOS) aimed at enhancing the outage performance of non-orthogonal multiple access (NOMA) systems. By considering the diverse target rates of users, new important properties of NOMA are revealed: When users’ target rates satisfy certain conditions, the channel state information (CSI) is not required by PA-DOS to minimize the system outage probability, and different users’ outage probabilities can be minimized simultaneously;When such conditions are not satisfied, the opposite situation occurs. Following these properties, two PA-DOS strategies are designed regarding distinct user priorities, which ensure the minimization of the system outage probability and the user outage probability of the high-priority user. Especially, these strategies do not require CSI or only require one-bit CSI feedback depending on users’ target rates. Analytical and numerical results are provided to demonstrate that the proposed strategies significantly outperform the existing strategies in terms of both system and user outage performance. Furthermore, the results show that although under some target rates the minimum user outage probabilities cannot be simultaneously achieved, they can be closely approached at the same time in the high-signal-to-noise-ratio regime by the proposed strategies. Copyright © 2022, The Authors. All rights reserved.

关键词： Channel state information

Intelligent Reflecting Surface Enabled Sensing: Cramér-Rao Lower Bound optimization

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Intelligent Reflecting Surface Enabled Sensing: Cramér-Rao ...

IEEE Globecom Workshops

作者： Xianxin Song Jie Xu Fan Liu Tony Xiao Han Yonina C. Eldar School of Science and Engineering Future Network of Intelligence Institute and Guangdong Provincial Key Laboratory of Future Networks of Intelligence The Chinese University of Hong Kong (Shenzhen) China Department of Electrical and Electronic Engineering Southern University of Science and Technology China wireless Technology Lab 2012 Laboratories Huawei China Faculty of Mathematics and Computer Science Weizmann Institute of Science Israel

ISBN: (纸本)9781665459761

This paper investigates intelligent reflecting surface (IRS) enabled non-line-of-sight (NLoS) wireless sensing, in which an IRS is deployed to assist an access point (AP) to sense a target in its NLoS region. It is assumed that the AP is equipped with multiple antennas and the IRS is equipped with a uniform linear array. The AP aims to estimate the target’s direction-of-arrival (DoA) with respect to the IRS, based on the echo signals from the AP-IRS-target-IRS-AP link. Under this setup, we jointly design the transmit beamforming at the AP and the reflective beamforming at the IRS to minimize the CramérRao lower bound (CRLB) on estimation error. Towards this end, we first obtain the CRLB expression for estimating the DoA in closed form. Next, we optimize the joint beamforming design to minimize the CRLB, via alternating optimization, semi-definite relaxation, and successive convex approximation. Numerical results show that the proposed design based on CRLB minimization achieves improved sensing performance in terms of mean squared error, as compared to the traditional schemes with signal-to-noise ratio maximization and separate beamforming.

关键词： Wireless communication Wireless sensor networks Estimation error Direction-of-arrival estimation Array signal processing Minimization Sensors

Caching and Computation Offloading in High Altitude Platform Station (HAPS) Assisted Intelligent Transportation Systems

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arXiv 2021年

作者： Ren, Qiqi Abbasi, Omid Kurt, Gunes Karabulut Yanikomeroglu, Halim Chen, Jian The State Key Laboratory of Integrated Service Networks Xidian University Shaanxi Xi'An710071 China The Department of Systems and Computer Engineering Carleton University OttawaON Canada The Department of Electrical Engineering Polytechnique Montréal Montréal Canada

Edge intelligence, a new paradigm to accelerate artificial intelligence (AI) applications by leveraging computing resources on the network edge, can be used to improve intelligent transportation systems (ITS). However, due to physical limitations and energy-supply constraints, the computing powers of edge equipment are usually limited. High altitude platform station (HAPS) computing can be considered to be a promising extension of edge computing. HAPS is deployed in the stratosphere to provide wide coverage and strong computational capabilities. It is suitable to coordinate terrestrial resources and store the fundamental data associated with ITS-based applications. In this work, three computing layers, i.e., vehicles, terrestrial network edges, and HAPS, are integrated to build a computation framework for ITS, where the HAPS data library stores the fundamental data needed for the applications. In addition, the caching technique is introduced for network edges to store some of the fundamental data from the HAPS so that large transmission delays can be reduced. We aim to minimize the delay of the system by optimizing computation offloading and caching decisions as well as bandwidth and computing resource allocations. The simulation results highlight the benefits of HAPS computing for mitigating delays and the significance of caching at network edges. Copyright © 2021, The Authors. All rights reserved.

关键词： Intelligent systems