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arXiv 2020年

作者： Ahmadi, Samim Hauffen, Jan Christian Kästner, Linh Jung, Peter Caire, Giuseppe Ziegler, Mathias Bundesanstalt für Materialforschung und -prüfung Berlin Germany Chair Industry Grade Networks and Clouds Faculty of Electrical Engineering and Computer Science Berlin Institute of Technology Berlin Germany Chair Communication and Information Theory Berlin Institute of Technology Berlin Germany

Block-sparse regularization is already well-known in active thermal imaging and is used for multiple measurement based inverse problems. The main bottleneck of this method is the choice of regularization parameters which differs for each experiment. To avoid time-consuming manually selected regularization parameter, we propose a learned block-sparse optimization approach using an iterative algorithm unfolded into a deep neural network. More precisely, we show the benefits of using a learned block iterative shrinkage thresholding algorithm that is able to learn the choice of regularization parameters. In addition, this algorithm enables the determination of a suitable weight matrix to solve the underlying inverse problem. Therefore, in this paper we present the algorithm and compare it with state of the art block iterative shrinkage thresholding using synthetically generated test data and experimental test data from active thermography for defect reconstruction. Our results show that the use of the learned block-sparse optimization approach provides smaller normalized mean square errors for a small fixed number of iterations than without learning. Thus, this new approach allows to improve the convergence speed and only needs a few iterations to generate accurate defect reconstruction in photothermal super resolution imaging. © 2020, CC BY.

关键词： Mean square error

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Secure Precoding Aided Spatial Modulation via Transmit Antenna Selection

Secure Precoding Aided Spatial Modulation via Transmit Anten...

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作者： Huang, Yu Wen, Miaowen Zheng, Beixiong Cheng, Xiang Yang, Liuqing Ji, Fei School of Electronics and Information Engineering South China University of Technology Guangzhou510641 China State Key Laboratory of Advanced Optical Communication Systems and Networks School of Electronics Engineering and Computer Science Peking University Beijing China Department of Electrical and Computer Engineering Colorado State University Fort CollinsCO80523 United States

In this paper, two transmit antenna selection schemes are proposed for precoding-aided spatial modulation (PSM) to enhance the secrecy performance with reduced hardware complexity. The first strategy is determined by the channel state information (CSI) of both the legitimate and illegitimate links, called deterministic antenna selection based PSM (DAS-PSM), which selects partial transmit antennas to implement zero-forcing (ZF) precoding for maximizing the secrecy rate. For practical implementation, the low-complexity DAS-PSM criterion is demonstrated. The second strategy resorts to random antenna selection (RAS) with the aid of fast radio-frequency switching. Different from the DAS-PSM, this so-called RAS based PSM (RAS-PSM) dispenses with the CSI of the wiretap channel, which generates the ZF precoding matrix associated with randomly selected transmit antenna combination during each symbol period, creating additional turbulence that solely affects the eavesdropper. To combat the issue of low secrecy rate in the high signal-to-noise ratio regime due to the finite-alphabet inputs, time-varying artificial noise with extra power can be incorporated into both aforementioned strategies, which is exemplified in the RAS-PSM. Finally, the secrecy rates of both proposed schemes are theoretically analyzed and evaluated via Monte Carlo simulations, demonstrating that both proposed schemes with different requirements are capable of enhancing the secrecy performance compared to the conventional PSM. © 1967-2012 IEEE.

关键词： Channel state information

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V-Edge: Virtual edge computing as an enabler for novel microservices and cooperative computing

arXiv

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arXiv 2021年

作者： Dressler, Falko Chiasserini, Carla Fabiana Fitzek, Frank H.P. Karl, Holger Cigno, Renato Lo Capone, Antonio Casetti, Claudio Malandrino, Francesco Mancuso, Vincenzo Klingler, Florian Rizzo, Gianluca The School of Electrical Engineering and Computer Science TU Berlin Berlin Germany The Dept. of Electronics and Telecommunications Politecnico di Torino Torino Italy The School of Engineering Sciences as well as the Excellence Cluster CeTI TU Dresden Dresden Germany The Hasso-Plattner-Institute Potsdam Germany The Dept. of Information Engineering University of Brescia Brescia Italy The Dept. of Electronics Information and Bioengineering Politecnico di Milano Milano Italy The Dept. of Control and Computer Engineering Politecnico di Torino Torino Italy The Institute of Electronics Computer and Communication Engineering of the National Research Council of Italy Torino Italy IMDEA Networks Madrid Spain The Dept. of Computer Science Paderborn University Paderborn Germany The Research Institute of Information Systems HES-SO Valais-Wallis Switzerland University of Foggia Italy

As we move from 5G to 6G, edge computing is one of the concepts that needs revisiting. Its core idea is still intriguing: instead of sending all data and tasks from an end user's device to the cloud, possibly covering thousands of kilometers and introducing delays that are just owed to limited propagation speed, edge servers deployed in close proximity to the user, e.g., at some 5G gNB, serve as proxy for the cloud. Yet this promising idea is hampered by the limited availability of such edge servers. In this paper, we discuss a way forward, namely the virtual edge computing (V-Edge) concept. V-Edge bridges the gap between cloud, edge, and fog by virtualizing all available resources including the end users' devices and making these resources widely available using well-defined interfaces. V-Edge also acts as an enabler for novel microservices as well as cooperative computing solutions. We introduce the general V-Edge architecture and we characterize some of the key research challenges to overcome, in order to enable wide-spread and even more powerful edge services. Copyright © 2021, The Authors. All rights reserved.

关键词： Edge computing

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Beamforming Design and Association Scheme for Multi-RIS Multi-User mmWave Systems Through Graph Neural networks

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IEEE Transactions on Wireless communications 2025年

作者： Liu, Mengbing Huang, Chongwen Alhammadi, Ahmed Renzo, Marco Di Debbah, Merouane Yuen, Chau Nanyang Technological University School of Electrical and Electronics Engineering 639798 Singapore Zhejiang University College of Information Science and Electronic Engineering Hangzhou310027 China Zhejiang Provincial Key Laboratory of Multi-Modal Communication Networks and Intelligent Information Processing Hangzhou310027 China Technology Innovation Institute Masdar City Abu Dhabi United Arab Emirates Université Paris-Saclay CNRS Laboratoire des Signaux et Systèmes CentraleSupélec 3 Rue Joliot-Curie Gif-sur-Yvette91192 France King’s College London Centre for Telecommunications Research – Department of Engineering LondonWC2R 2LS United Kingdom Khalifa University KU6G. Research Center Department of Computer and Information Engineering Abu Dhabi127788 United Arab Emirates University Paris-Saclay CentraleSupelec Gif-sur-Yvette91192 France

Reconfigurable intelligent surface (RIS) is emerging as a promising technology for next-generation wireless communication networks, offering a variety of merits such as the ability to tailor the communication environment. Moreover, deploying multiple RISs helps mitigate severe signal blocking between the base station (BS) and users, providing a practical and efficient solution to enhance the service coverage. However, fully reaping the potential of a multi-RIS aided communication system requires solving a non-convex optimization problem. This challenge motivates the adoption of learning-based methods for determining the optimal policy. In this paper, we introduce a novel heterogeneous graph neural network (GNN) to effectively leverage the graph topology of a wireless communication environment. Specifically, we design an association scheme that selects a suitable RIS for each user. Then, we maximize the weighted sum rate (WSR) of all the users by iteratively optimizing the RIS association scheme, and beamforming designs until the considered heterogeneous GNN converges. Based on the proposed approach, each user is associated with the best RIS, which is shown to significantly improve the system capacity in multi-RIS multi-user millimeter wave (mmWave) communications. Specifically, simulation results demonstrate that the proposed heterogeneous GNN closely approaches the performance of the high-complexity alternating optimization (AO) algorithm in the considered multi-RIS aided communication system, and it outperforms other benchmark schemes. Moreover, the performance improvement achieved through the RIS association scheme is shown to be of the order of 30%. © 2002-2012 IEEE.

关键词： Beamforming

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A Virtual Machine Placement Algorithm Combining NSGA-II and Bin-Packing Heuristic

A Virtual Machine Placement Algorithm Combining NSGA-II and ...

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IEEE International Conference on Parallel and Distributed Computing, Applications and Technologies (PDCAT)

作者： Wenting Wei Kun Wang Kexin Wang Shengjun Guo Huaxi Gu State Key Laboratory of Integrated Service Networks Xidian University Xi???an China Science and Technology on Communication Networks Laboratory Shijiazhuang China School of Computer and Technology Science and Technology Xidian University Xi???an China

ISBN: (数字)9781728126166

ISBN: (纸本)9781728126173

The servers in the data center networks have multi-dimensional physical resources, and there is a lot of diversity in resource consumption among tasks. When virtual machines carrying different user requests are deployed on the same server at the same time, it is very likely that there is an imbalanced usage of multi-dimensional resources, resulting in the waste of physical resources. In this paper, we focus on virtual machine placement in data centers aiming to balance multi-dimensional resource usage and maximize the service rate. To solve such a bi-objective optimization problem, we present a joint bin-packing heuristic and genetic algorithm to reduce the time complexity while obtaining an approximate optimal solution.

关键词： Virtual machining Servers Data centers Genetic algorithms Resource management Time complexity Optimization

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Long-distance continuous-variable quantum key distribution over 202.81 km fiber

arXiv

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arXiv 2020年

作者： Zhang, Yichen Chen, Ziyang Pirandola, Stefano Wang, Xiangyu Zhou, Chao Chu, Binjie Zhao, Yijia Xu, Bingjie Yu, Song Guo, Hong State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications Beijing100876 China State Key Laboratory of Advanced Optical Communication Systems and Networks Department of Electronics Center for Quantum Information Technology Peking University Beijing100871 China Computer Science and York Centre for Quantum Technologies University of York YorkYO10 5GH United Kingdom Science and Technology on Security Communication Laboratory Institute of Southwestern Communication Chengdu610041 China

Quantum key distribution (QKD) [1–3] provides secure keys resistant to code-breaking quantum computers. The continuous-variable version of QKD [1, 4–6] offers the advantages of higher secret key rates in metropolitan areas, as well as the use of standard telecom components that can operate at room temperature [7–10]. However, the transmission distance of these systems (compared with discrete-variable systems) are currently limited and considered unsuitable for long-distance distribution [11]. Herein, we report the experimental results of long distance continuous-variable QKD over 202.81 km of ultralow-loss optical fiber by suitably controlling the excess noise and employing highly-efficient reconciliation procedures. This record-breaking implementation of the continuous-variable QKD doubles the previous distance record and shows the road for long-distance and large-scale secure QKD using room-temperature standard telecom components. Copyright © 2020, The Authors. All rights reserved.

关键词： Quantum cryptography

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Real Time Detection of Object Blob Localization Application using 1-D Connected Pixel and Windowing Method on FPGA

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Journal of Physics: Conference Series 2021年第1期1755卷

作者： CheeYuen Lam Phaklen Ehkan Rafikha Aliana A. Raof Suwimol Jungjit Embedded Networks and Advanced Computing (ENAC) Research Cluster School of Computer and Communication Engineering Universiti Malaysia Perlis Arau Perlis Malaysia. Department of Computer and Information Technology Faculty of Science Thaksin University Phatthalung Thailand.

Blob detection and localization is a common process used in the machine vision. Current existing blob detection method is using 2-dimensional kernel matrix which is higher in time consumption and also memory space. This study has proposed a dedicated digital architecture consist of two modules to detect binary image blob using only 1 -dimensional image pixel. First module is used to detect connected pixel in a row of pixel, and second module is used to perform windowing to justify blob location. This study has been successfully implemented and tested on Altera DE2 FPGA board. The proposed architecture only takes 24 clock cycles to deliver blob location and related features. The tested architecture only utilizes 1597 logic element, or 4.81% of the FPGA total resources.

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Femtosecond fiber laser at 780 nm for two-photon autofluorescence imaging

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Chinese Optics Letters 2019年第7期17卷 63-65页

作者： Wan Yang Danlei Wu Runlong Wu Guanyu Liu Bingying Chen Lishuang Feng Zhigang Zhang Aimin Wang State Key Laboratory of Advanced Optical Communication System and Networks School of Electronics Engineering and Computer SciencePeking UniversityBeijing 1008711 China Key Laboratory of Precision Opto-Mechatronics Technology Ministry of EducationSchool of Instrumentation Science&Optoelectronics EngineeringBeihang UniversityBeijing 100191China

We present an Er-doped fiber(Er:fiber)-based femtosecond laser at 780 nm with 256 MHz repetition rate, 191 fs pulse duration, and over 1 W average *** from the careful third-order dispersion management, we introduce moderate self-phase modulation to broaden the output spectrum of the Er:fiber amplifier and achieve 193 fs pulse duration and 2.43W average *** 40% frequency doubling efficiency is obtained by a periodically poled lithium niobate *** through a hollow-core photonic bandgap fiber, this robust laser becomes an ideal and convenient light source for two-photon autofluorescence imaging.

关键词： Femtosecond fiber laser two-photon autofluorescence imaging

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Colour Characterization and Detection of Dry Chinese Sausage Casing Twist using Colour Image Analysis

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Journal of Physics: Conference Series 2021年第1期1755卷

作者： CheeYuen Lam Phaklen Ehkan Suwimol Jungjit Embedded Networks and Advanced Computing (ENAC) Research Cluster School of Computer and Communication Engineering Universiti Malaysia Perlis Arau Perlis Malaysia. Department of Computer and Information Technology Faculty of Science Thaksin University Phatthalung Thailand.

Chinese sausage is traditional air-dry sausage that loved by the Chinese community around the globe. This sausage can be served alone after steam cook or cook with other ingredients to create other tasty Chinese delicacies. However, a manual hand cutting process is required to cut out the sausage linking twist during the sausage's packaging phase. This hand cutting process is tedious, time consuming and danger to workers. This study has proposed two types of sausage casing twist detector using image processing technique based on HSL and RGB colour characteristic and a set of blob detection technique to detect sausage casing twist blob on the output image. Hue, green-blue and red-blue colour characteristics are found being significant to represent the sausage casing twist in the sample images and used in the proposed algorithms. The RGB based algorithm is capable to produce a low noise image with SNR of 3.73dB as compared to Hue-based detector at -8.89dB which unsuccessful to remove shadow and object outlining of the output image. The proposed blob detection algorithm is able to detect 73.02% of the blob in hue-based image while 94.18% in RGB based image. The false detection rate in hue-based image has reached 333.33% compared to 12.17 % in RGB based image.

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Joint Optimization of Phase Retrieval and Forward Error Correcting for Direct Detection Receiver

Joint Optimization of Phase Retrieval and Forward Error Corr...

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European Conference on Optical communication (ECOC)

作者： Bin Chen Hanzi Huang Haoshuo Chen Yi Lei Nicolas K. Fontaine Roland Ryf Qianwu Zhang Yingxiong Song School of Computer Science and Information Engineering Hefei University of Technology China Key Laboratory of Specialty Fiber Optics and Optical Access Networks Joint International Research Laboratory of Specialty Fiber Optics and Advanced Communication Shanghai University China Nokia Bell Labs Holmdel New Jersey USA

We have experimentally demonstrated that performance of a phase retrieval (PR) receiver in optical systems can be significantly improved by a joint optimization of PR pilots overhead and FEC coding overhead, enabling ... 详细信息

ISBN: (数字)9781728173610

ISBN: (纸本)9781728173627

关键词： Europe Forward error correction Optical receivers Adaptive optics Optical fiber communication Resource management Optimization

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