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A combinatorial algorithm for computing the rank of a generic partitioned matrix with 2 × 2 submatrices

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arXiv 2020年

作者： Hirai, Hiroshi Iwamasa, Yuni Department of Mathematical Informatics Graduate School of Information Science and Technology University of Tokyo Tokyo113-8656 Japan Department of Communications and Computer Engineering Graduate School of Informatics Kyoto University Kyoto606-8501 Japan

In this paper, we consider the problem of computing the rank of a block-structured symbolic matrix (a generic partitioned matrix) A = (Aαβxαβ), where Aαβ is a 2 × 2 matrix over a field F and xαβ is an indeterminate for α = 1, 2, . . ., µ and β = 1, 2, . . ., ν. This problem can be viewed as an algebraic generalization of the bipartite matching problem and was considered by Iwata and Murota (1995). Recent interests in this problem lie in the connection with non-commutative Edmonds’ problem by Ivanyos, Qiao, and Subrahamanyam (2018) and Garg, Gurvits, Oliveiva, and Wigderson (2019), where a result by Iwata and Murota implicitly states that the rank and non-commutative rank (nc-rank) are the same for this class of symbolic matrices. The main result of this paper is a simple and combinatorial O((µν)2 min{µ, ν})-time algorithm for computing the symbolic rank of a (2 × 2)-type generic partitioned matrix of size 2µ × 2ν. Our algorithm is inspired by the Wong sequence algorithm by Ivanyos, Qiao, and Subrahamanyam for the nc-rank of a general symbolic matrix, and requires no blow-up operation, no field extension, and no additional care for bounding the bit-size. Moreover it naturally provides a maximum rank completion of A for an arbitrary field F. Copyright © 2020, The Authors. All rights reserved.

关键词： Matrix algebra

Understanding UAV-based WPCN-aided capabilities for offshore monitoring applications

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arXiv 2020年

作者： Melgarejo, Dick Carrillo Mikhaylov, Konstantin Nardelli, Pedro J. Andreev, Sergey da Costa, Daniel B. LUT School of Energy Systems Lappeenranta-Lahti University of Technology Finland Centre for Wireless Communications University of Oulu Finland Unit of Electrical Engineering Tampere University Finland Department of Computer Engineering Federal University of Ceará Brazil

Despite the immense progress in the recent years, efficient solutions for monitoring remote areas are still missing today. This is especially notable in the context of versatile maritime and offshore use cases, owing to a broader span of operating regions and a lack of radio network infrastructures. In this article, we address the noted challenge by delivering a conceptual solution based on the convergence of three emerging technologies - unmanned aerial vehicles (UAVs), battery-less sensors, and wireless powered communication networks (WPCNs). Our contribution offers a systematic description of the ecosystem related to the proposed solution by identifying its key actors and design dimensions together with the relevant resources and performance metrics. A system-level modeling-based evaluation of an illustrative scenario delivers deeper insights into the considered operation and the associated trade-offs. Further, unresolved challenges and perspective directions are underpinned for a subsequent study. © 2020, CC BY.

关键词： Unmanned aerial vehicles (UAV)

Resource allocation for millimeter-wave train-ground communications in high-speed railway scenarios

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arXiv 2021年

作者： Zhang, Xiangfei Niu, Yong Mao, Shiwen Cai, Yunlong He, Ruisi Ai, Bo Zhong, Zhangdui Liu, Yiru State Key Laboratory of Rail Traffic Control and Safety Frontiers Science Center for Smart High-speed Railway System Beijing Jiaotong University Beijing100044 China National Mobile Communications Research Laboratory Southeast University Nanjing211189 China Department of Electrical and Computer Engineering Auburn University AuburnAL36849-5201 United States Department of ISEE Zhejiang University China State Key Laboratory of Rail Traffic Control and Safety Beijing Engineering Research Center of High-speed Railway Broadband Mobile Communications School of Electronic and Information Engineering Beijing Jiaotong University Beijing100044 China

With the development of wireless communication, higher requirements arise for train-ground wireless communications in high-speed railway (HSR) scenarios. The millimeter-wave (mm-wave) frequency band with rich spectrum resources can provide users in HSR scenarios with high performance broadband multimedia services, while the full-duplex (FD) technology has become mature. In this paper, we study train-ground communication system performance in HSR scenarios with mobile relays (MRs) mounted on rooftop of train and operating in the FD mode. We formulate a nonlinear programming problem to maximize network capacity by allocation of spectrum resources. Then, we develop a sequential quadratic programming (SQP) algorithm based on the Lagrange function to solve the bandwidth allocation optimization problem for track-side base station (BS) and MRs in this mm-wave train-ground communication system. Extensive simulation results demonstrate that the proposed SQP algorithm can effectively achieve high network capacity for train-ground communication in HSR scenarios while being robust to the residual self-interference (SI). Copyright © 2021, The Authors. All rights reserved.

关键词： Resource allocation

Performance Analysis of Fluid Antenna System under Spatially-Correlated Rician Fading Channels

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arXiv 2025年

作者： Huangfu, Jiangsheng Song, Zhengyu Hou, Tianwei Li, Anna Liu, Yuanwei Nallanathan, Arumugam Wong, Kai-Kit School of Electronic and Information Engineering Beijing Jiaotong University Beijing100044 China School of Computing and Communications Lancaster University LancasterLA1 4WA United Kingdom Department of Electrical and Electronic Engineering The University of Hong Kong Hong Kong School of Electronic Engineering and Computer Science Queen Mary University of London London United Kingdom Department of Electronic Engineering Kyung Hee University Gyeonggi-do Yongin-si17104 Korea Republic of Department of Electronic and Electrical Engineering University College London LondonWC1E 7JE United Kingdom

Fluid antenna systems (FAS) are among the most promising technologies for the sixth generation (6G) mobile communication networks. Unlike traditional fixed-position multiple-input multiple-output (MIMO) systems, a FAS possesses position reconfigurability to switch on-demand among N predefined ports over a prescribed space. This paper explores the performance of a single-input single-output (SISO) model with a fixed-position antenna transmitter and a single-antenna FAS receiver, referred to as the Rx-SISO-FAS model, under spatially-correlated Rician fading channels. Our contributions include exact expressions and closed-form bounds for the outage probability of the Rx-SISO-FAS model, as well as exact and closed-form lower bounds for the ergodic rate. Importantly, we also analyze the performance considering both uniform linear array (ULA) and uniform planar array (UPA) configurations for the ports of the FAS. To gain insights, we evaluate the diversity order of the proposed model and our analytical results indicate that with a fixed overall system size, increasing the number of ports, N, significantly decreases the outage performance of FAS under different Rician fading factors. Our numerical results further demonstrate that: i) the Rx-SISO-FAS model can enhance performance under spatially-correlated Rician fading channels over the fixed-position antenna counterpart;ii) the Rician factor negatively impacts performance in the low signal-to-noise ratio (SNR) regime;iii) FAS can outperform an L branches maximum ratio combining (MRC) system under Rician fading channels;and iv) when the number of ports is identical, UPA outperforms ULA. Copyright © 2025, The Authors. All rights reserved.

关键词： Fading channels

Pseudonym Authentication on Network Layer in Information-Centric Networks 2

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Pseudonym Authentication on Network Layer in Information-Cen...

2nd IEEE International Conference on Hot Information-Centric Networking, HotICN 2019

作者： Jiang, Zuoqi Luo, Jiangtao Zhang, Fei He, Chen Wang, Mengnan Zhang, Yanyong School of Communications and Information Engineering Electronic Information and Networking Research Institute Chongqing University of Posts and Telecommunication Chongqing400065 China Rutgers University Department of Electrical and Computer Engineering North BrunswickNJ08902 United States

ISBN: (纸本)9781728157818

The current data-centric security architecture for the Information Centric Network (ICN) does not provide efficient user authentication mechanisms, thus causing undesirable issues such as interest flooding a ttacks (IFA). I no rder to address them, this paper proposes a pseudonym authentication scheme on network layer based on the system of identity-based cryptography (IBC). In the proposed approach, each consumer needs to be authenticated before sending Interest packets into the network. After successful authentication, the consumer will be assigned a temporary nickname to be used in later data request. During the procedure, IBC is adopted to protect real names of consumers and verify the interest origin. As a result, this approach can complete user authentication and protect his real identity simultaneously. The proposed approach is case studied in IFA depression and expected results are achieved. © 2019 IEEE.

关键词： Network layers

Capacity and optimal resource allocation for IRS-assisted multi-user communication systems

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arXiv 2020年

作者： Mu, Xidong Liu, Yuanwei Guo, Li Lin, Jiaru Al-Dhahir, Naofal School of Artificial Intelligence Key Laboratory of Universal Wireless Communications Ministry of Education Beijing University of Posts and Telecommunications Beijing China School of Electronic Engineering and Computer Science Queen Mary University of London London United Kingdom Department of Electrical and Computer Engineering The University of Texas at Dallas RichardsonTX75080 United States

The fundamental capacity limits of intelligent reflecting surface (IRS)-assisted multi-user wireless communication systems are investigated in this paper. Specifically, the capacity and rate regions for both capacity-achieving non-orthogonal multiple access (NOMA) and orthogonal multiple access (OMA) transmission schemes are characterized by jointly optimizing the IRS reflection matrix and wireless resource allocation under the constraints of a maximum number of IRS reconfiguration times. In NOMA, all users are served in the same resource blocks by employing superposition coding and successive interference cancelation techniques. In OMA, all users are served by being allocated orthogonal resource blocks of different sizes. For NOMA, the ideal case with an asymptotically large number of IRS reconfiguration times is firstly considered, where the optimal solution is obtained by employing the Lagrange duality method. Inspired by this result, an inner bound of the capacity region for the general case with a finite number of IRS reconfiguration times is derived. For OMA, the optimal transmission strategy for the ideal case is to serve each individual user alternatingly with its effective channel power gain maximized. Based on this result, a rate region inner bound for the general case is derived. Finally, numerical results are provided to show that: i) a significant capacity and rate region improvement can be achieved by using IRS;ii) the capacity gain can be further improved by dynamically configuring the IRS reflection matrix. Copyright © 2020, The Authors. All rights reserved.

关键词： Matrix algebra

Accurate antenna gain estimation using the two-antenna method

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Accurate antenna gain estimation using the two-antenna metho...

Antennas and Propagation Conference 2019, APC 2019

作者： Mistry, Keyur K. Lazaridis, Pavlos I. Zaharis, Zaharias D. Akinsolu, Mobayode Liu, Bo Loh, Tian Department of Engineering and Technology University of Huddersfield United Kingdom Department of Electrical and Computer Engineering Aristotle University of Thessaloniki Greece Department of Computing and Engineering Wrexham Glyndwr University United Kingdom 5G and Future Communications Technology Group National Physical Laboratory Teddington United Kingdom

ISBN: (纸本)9781839531705

This paper demonstrates a simulation-assisted measurement technique to determine the gain of an antenna accurately in an open test site. This technique is based on two-antenna gain determination method using Friis equation, with the actual measurement test setup re-created in CST Studio Suite for simulation. A log-periodic dipole antenna is used to validate the gain determination technique in this paper. The simulation of two-antenna gain determination method is demonstrated in this paper to estimate an appropriate separation distance between the two antennas that needs to be used for actual measurements. Estimating and determining the separation distance using several simulations saves time as it eliminates the need to perform the measurement at various separation distances. The measured realized gain obtained using this technique provides good agreement with the simulation and thus validates the accuracy of this technique. The proposed gain determination technique is a cost-effective technique as it requires the use of open test site, which serves as an alternative to expensive measurements performed in anechoic chambers. © 2019 Institution of engineering and Technology. All rights reserved.

关键词： Cost effectiveness

Realization of Resonant Optical Metasurfaces with Maximal and Tunable Chiral Response

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Realization of Resonant Optical Metasurfaces with Maximal an...

Conference on Lasers and Electro-Optics (CLEO)

作者： Tan Shi Zi-Lan Deng Guangzhou Geng Yixuan Zeng Guangwei Hu Adam Overvig Junjie Li Cheng-Wei Qiu Andrea Alù Yuri S. Kivshar Xiangping Li Institute of Photonics Technology Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications Jinan University Guangzhou China Institute of Physics Beijing National Laboratory for Condensed Matter Physics Chinese Academy of Sciences Beijing China Department of Electrical and Computer Engineering National University of Singapore Kent Ridge Republic of Singapore Photonics Initiative Advanced Science Research Center City University of New York New York NY USA Nonlinear Physics Center Australian National University Canberra ACT Australia

We employ the physics of chiral bound state in the continuum and suggest planar chiral metasurfaces with near-perfect circular dichroism (CD). We demonstrate experimentally metasurfaces with CD=0.9 with Q factor excee... 详细信息

ISBN: (数字)9781957171050

ISBN: (纸本)9781665466660

关键词： Q-factor Laser theory Resonant frequency Lighting Lasers and electrooptics Metasurfaces Electrooptical waveguides

Correction to: NOMA for 5G and beyond: literature review and novel trends

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Wireless Networks 2022年第4期29卷 1655-1655页

作者： Abd-Elnaby, Mohammed Sedhom, Germien G. El-Rabaie, El-Sayed M. Elwekeil, Mohamed Department of Computer Engineering College of Computers and Information Technology Taif University Taif Saudi Arabia Department of Electronics and Electrical Communication Delta Higher Institute for Engineering and Technology Talkha Egypt Department of Electronics and Electrical Communications Engineering Faculty of Electronic Engineering Menoufia University Menouf Egypt Department of Electrical and Information Engineering University of Cassino and Southern Lazio Cassino Italy