Article
Telecommunications
Huiyuan Yang, Chang Cai, Xiaojun Yuan, Yingchang Liang
Summary: This paper investigates a multiuser multiple-input single-output wireless power transfer system assisted by reconfigurable intelligent surfaces, using a constant-envelope analog beamformer to jointly optimize ET beamforming and RIS phase shifts in order to maximize minimum received power. The non-convex max-min problem is iteratively solved using the successive convex approximation (SCA) method and alternating direction method of multipliers (ADMM) algorithm, demonstrating the effectiveness of the proposed algorithm and the performance gain brought by RISs.
CHINA COMMUNICATIONS
(2021)
Article
Computer Science, Theory & Methods
Serdar Metin, Can Ozturan
Summary: In order to execute transactions on the Ethereum Mainnet and other blockchains, users need to pay fees in the form of cryptocurrency. While Ether can be purchased for the Ethereum blockchain, test networks and research blockchains distribute free Ether to users. Due to the consumption of blockchain resources, Ether is distributed in fixed small amounts. To address different user requirements and ensure fairness, a more general distribution mechanism based on Max-min Fairness is proposed. This research presents an algorithm and Solidity smart contract implementation that achieves low transaction costs independent of the number of users.
FUTURE GENERATION COMPUTER SYSTEMS-THE INTERNATIONAL JOURNAL OF ESCIENCE
(2022)
Article
Engineering, Electrical & Electronic
Ahmet Zahid Yalcin, Mustafa Kagan Cetin, Melda Yuksel
Summary: The paper jointly designs precoders and power allocation coefficients for a downlink NOMA wireless communication system to achieve max-min fairness among the strongest users in each group while maintaining minimum target rates for other users. The proposed solutions are based on SDR, SCA, and MMSE approaches, with a simplification suggested for the MMSE method to reduce complexity. Results show that while RS offers the best MMF rates, the low-complexity MMSE approach has the least complexity, and the SDR/SCA approach provides a good tradeoff between the two.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2021)
Article
Engineering, Electrical & Electronic
Chengwen Xing, Siyuan Xie, Shiqi Gong, Xuanhe Yang, Sheng Chen, Lajos Hanzo
Summary: In this paper, we investigate the fundamental role of Karush-Kuhn-Tucker (KKT) conditions based optimization in many core problems of signal processing and wireless communications, particularly in the context of optimizing positive semidefinite matrix variables under nonconvex rank constraints. Specifically, we optimize a reconfigurable intelligent surface (RIS) aided multi-user multi-input multi-output (MU-MIMO) network based on the properties of KKT conditions. Our simulation results demonstrate the performance advantages of the proposed framework.
IEEE TRANSACTIONS ON COMMUNICATIONS
(2023)
Article
Engineering, Electrical & Electronic
Hsiao-Feng Lu
Summary: This paper investigates the aspects of sum rate and fairness for dirty paper coding (DPC) based MIMO downlink communications. An efficient waterfilling algorithm is proposed to achieve achievable rates with the best possible fairness values.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Jiangwei Sui, Cuixia Huang, Yi-Feng Cheng
Summary: This article proposes a multielement fully decoupled linearly placed inverted-F antenna (IFA) array for mobile terminals. A hybrid decoupling method is used to mitigate the mutual couplings among the multiple IFAs. The decoupling capacitors and T-shaped mode transformers are introduced to decouple the IFAs and broaden the impedance bandwidth. Experimental results show significant reduction in mutual couplings and improved total efficiencies throughout the band.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2022)
Article
Engineering, Electrical & Electronic
Anup Mishra, Yijie Mao, Onur Dizdar, Bruno Clerckx
Summary: This work focuses on the precoder design problem of Rate-Splitting Multiple Access (RSMA) scheme in multi-user multi-antenna communications. Unlike existing works, this study considers multi-antenna receivers and optimizes the precoder to maximize the Weighted Ergodic Sum-Rate (WESR). The results show that RSMA outperforms conventional schemes and Non-Orthogonal Multiple Access (NOMA) in terms of sum-Degree of Freedom (DoF) and Ergodic Sum Rate (ESR) performance, especially in the presence of imperfect Channel State Information at the Transmitter (CSIT), network loads, and user deployments.
IEEE TRANSACTIONS ON COMMUNICATIONS
(2022)
Article
Engineering, Electrical & Electronic
Kin-Lu Wong, Ching-Jui Chen, Wei-Yu Li
Summary: The study presents four dual-band shorted patch antennas with a low profile of 1 mm for 4 x 4 MIMO operation in mobile devices. Each antenna consists of a larger shorted patch and a smaller shorted patch to generate signals at 2.4 GHz and 5.8 GHz bands, respectively.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Computer Science, Artificial Intelligence
Ruihang Ji, Dongyu Li, Jie Ma, Shuzhi Sam Ge
Summary: This article investigates the saturation-tolerant prescribed control (SPC) for multiinput and multioutput nonlinear systems with unknown control directions and actuator faults. By proposing a concise tunnel prescribed performance (TPP) and constructing a novel auxiliary system, the control scheme is able to degrade performance constraints in the case of saturation and recover back to the user-specified performance without saturation. Furthermore, the proposed control scheme guarantees finite-time convergence and SPP-constrained tracking performance despite input saturation and uncertainties.
IEEE TRANSACTIONS ON FUZZY SYSTEMS
(2022)
Article
Engineering, Electrical & Electronic
Akira Kawai, Masanori Nakamura, Takayuki Kobayashi, Yutaka Miyamoto
Summary: To address signal impairments caused by characteristic differences and crosstalk, we propose a method for fully frequency-resolved four-dimensional characterization of IQ impairments. By formulating a 4D signal-propagation model, we separate the 4D IQ characteristics of the transmitter and receiver from the coefficients of an adaptive equalizer. We also demonstrate the feasibility of our method with numerical and experimental testing using 96-Gbaud 16QAM signals.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Computer Science, Information Systems
Wen Zhou, Yihan Xu, Chunguo Li
Summary: By offloading computational tasks to edge servers, edge computing can reduce the computational burden for mobile users and enhance user experience.
IEEE INTERNET OF THINGS JOURNAL
(2023)
Article
Engineering, Electrical & Electronic
Junpeng Li, Changchun Hua, Yana Yang
Summary: This article proposed an output space transfer (OST)-based multiinput-multioutput (MIMO) random vector functional-link networks (RVFLNs) to simultaneously model multiple MIQIs. By sparse learning of the OST matrix, the interindicator correlation is reasonably modeled, reducing the impact of missing indicators on modeling accuracy. An effective alternative optimization algorithm is presented to solve the corresponding knotty optimization problem and the actual data test shows that the proposed method can greatly improve the accuracy of multiple MIQIs estimation.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2021)
Article
Economics
Jakob Ahlrichs, Sebastian Rockstuhl
Summary: This study examines the fair percentage-retrofitting-fee in rental building retrofits in Germany and analyzes the impact of subsidies and environmental taxes on fair fees. The results show that the current regulations are unfair for both landlords and tenants, and the fair fee increases with higher subsidy levels or emission tax rates.
Article
Telecommunications
Tiantian Li, Haixia Zhang, Shuaishuai Guo, Dongfeng Yuan
Summary: This paper proposes a max-min fair RIS-aided rate-splitting multiple access (MMF-RIS-RSMA) scheme for multigroup multicast communications, where the rate fairness is obtained by maximizing the minimum group-rate. The optimization problem is divided into two subproblems and alternately optimized in order to achieve the solution. Simulations show that the proposed MMF-RIS-RSMA scheme can achieve significant performance improvement in terms of the minimum group-rate.
CHINA COMMUNICATIONS
(2023)
Article
Computer Science, Artificial Intelligence
Yu. E. Malashenko, I. A. Nazarova
Summary: This study examines distribution strategies for flows in a multicommodity network model, including strategies that equalize flows and strategies that achieve equal value resources. Computational experiments were conducted to compare the distribution strategies in networks with different structures.
JOURNAL OF COMPUTER AND SYSTEMS SCIENCES INTERNATIONAL
(2023)
Article
Engineering, Electrical & Electronic
Zhiguo Ding, H. Vincent Poor
Summary: This paper investigates the application of non-orthogonal multiple access (NOMA) in terahertz (THz) networks. It studies how pre-configured spatial beams in a legacy THz system can be used as bandwidth resources to serve additional secondary users without degrading the performance of primary users. The paper formulates a joint beam management and power allocation problem and proposes two methods to solve it. Analytical and simulation results demonstrate the effectiveness of beam-based resource allocation in THz-NOMA networks for improving system throughput and connectivity in a spectrally efficient manner.
IEEE TRANSACTIONS ON COMMUNICATIONS
(2023)
Article
Engineering, Electrical & Electronic
Siyuan Yu, Wei Chen, H. Vincent Poor
Summary: This paper presents a new data compression method that utilizes timing side information (TSI) obtained from two synchronized clocks at a remote sensor and a monitor, which has potential applications in the Industrial Internet of Things. By using TSI, the transmitter can send fewer bits to characterize the changing or holding time of a piecewise-constant stochastic process. The paper also explores the performance limits of TSI-based lossless and lossy compression, and develops practical low-complexity source coding schemes. Additionally, a real-time monitoring scheme is proposed, which does not require the sensor to measure the state transition time but uses a statistical signal processing algorithm to estimate the changing time accurately. Theoretical and numerical results demonstrate significant compression gain due to TSI, especially when communication latency and delay jitter are limited.
IEEE TRANSACTIONS ON COMMUNICATIONS
(2023)
Article
Computer Science, Information Systems
Changxiao Cai, H. Vincent Poor, Yuxin Chen
Summary: We study the distribution and uncertainty of non-convex optimization for noisy tensor completion, focusing on a two-stage estimation algorithm that characterizes the distribution of this nonconvex estimator. Our findings unveil the statistical optimality of nonconvex tensor completion, achieving un-improvable l(2) accuracy when estimating unknown tensor and underlying tensor factors.
IEEE TRANSACTIONS ON INFORMATION THEORY
(2023)
Article
Computer Science, Information Systems
Junyuan Gao, Yongpeng Wu, Shuo Shao, Wei Yang, H. Vincent Poor
Summary: This paper explores the massive random access problem in MIMO quasi-static Rayleigh fading channels, deriving bounds and evaluating the gap between achievability and converse bounds. It considers both the CSIR and no-CSI cases, including the scenarios with and without knowledge of the number of active users at the receiver. The results demonstrate the significance of MIMO for the problem, with spectral efficiency growing linearly with the number of receive antennas in the CSIR case. The scalability of the number of supported users is also analyzed.
IEEE TRANSACTIONS ON INFORMATION THEORY
(2023)
Article
Computer Science, Information Systems
Kangda Zhi, Cunhua Pan, Hong Ren, Kezhi Wang, Maged Elkashlan, Marco Di Renzo, Robert Schober, H. Vincent Poor, Jiangzhou Wang, Lajos Hanzo
Summary: This paper investigates the two-timescale transmission scheme for reconfigurable intelligent surface (RIS)-aided massive MIMO systems. The power scaling laws and the impact of various system parameters are analyzed. The performance under different conditions, such as spatially independent or correlated fading channels, is evaluated. The results show the benefits of deploying RIS close to cell-edge users and the modest gains obtained for users distributed over a large area.
IEEE TRANSACTIONS ON INFORMATION THEORY
(2023)
Article
Computer Science, Information Systems
Dinh C. Nguyen, Ming Ding, Pubudu N. Pathirana, Aruna Seneviratne, Jun Li, H. Vincent Poor
Summary: This article proposes a novel cooperative task offloading and block mining scheme for blockchain-based MEC system, aiming to maximize system utility by jointly optimizing offloading decision, channel selection, transmit power allocation, and computational resource allocation. Simulation results demonstrate significant improvement of system utility compared to baseline approaches.
IEEE TRANSACTIONS ON MOBILE COMPUTING
(2023)
Article
Engineering, Electrical & Electronic
Te-Yi Kan, Ronald Y. Y. Chang, Feng-Tsun Chien, Bing-Jia Chen, H. Vincent Poor
Summary: This paper investigates a multiuser downlink MISO system with a half-duplex DF relay and a full-duplex RIS. A joint design of active beamforming at the BS and DF relay, as well as passive beamforming at the RIS, is proposed for system sum-rate maximization. An AO-based algorithm is proposed to solve the challenging co-design problem. Numerical results demonstrate the superior performance and convergence of the proposed hybrid relay-RIS system.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2023)
Article
Computer Science, Information Systems
Eric Ruzomberka, David J. Love, Christopher G. Brinton, Arpit Gupta, Chih-Chun Wang, H. Vincent Poor
Summary: The demand for broadband wireless access is pushing the research and standardization of 5G and beyond-5G wireless systems. This paper aims to identify emerging security challenges for these wireless systems and propose multiple research areas to address these challenges.
IEEE SECURITY & PRIVACY
(2023)
Article
Engineering, Electrical & Electronic
Eyad Shtaiwi, Hongliang Zhang, Ahmed Abdelhadi, A. Lee Swindlehurst, Zhu Han, H. Vincent Poor
Summary: This paper proposes a method to address the potential harmful interference in integrated sensing and communication (ISAC) using a reconfigurable intelligent surface (RIS). The RIS can adjust the amplitude and phase shift of impinging signals, providing a high beamforming gain to maximize the communication system's sum-rate. Simulation results demonstrate that the proposed RIS-assisted design significantly reduces mutual interference and improves the system sum-rate for the communication system.
IEEE TRANSACTIONS ON COMMUNICATIONS
(2023)
Article
Engineering, Electrical & Electronic
Yapeng Zhao, Qingqing Wu, Wen Chen, Celimuge Wu, H. Vincent Poor
Summary: This article introduces a method to improve the performance of federated learning (FL) in AirComp by using intelligent reflecting surfaces (IRS). By designing multiple communication rounds to minimize the optimality gap of the loss function, this long-term design strategy achieves higher test accuracy in FL than the conventional isolated design approach.
IEEE TRANSACTIONS ON COMMUNICATIONS
(2023)
Article
Computer Science, Information Systems
Holger Boche, Rafael F. Schaefer, H. Vincent Poor
Summary: This paper addresses the question of whether it is possible to find algorithms that can compute the optimal input distribution for a given channel. Through the use of Turing machines concept, it is shown that it is impossible to algorithmically compute or approximate the capacity-achieving input distribution for discrete memoryless channels.
IEEE TRANSACTIONS ON INFORMATION THEORY
(2023)
Article
Engineering, Electrical & Electronic
Miroslav Mitev, Arsenia Chorti, H. Vincent Poor, Gerhard P. Fettweis
Summary: While existing security protocols focus on the core network, enhancing the security of the B5G access network is critically important, especially for novel use cases like mMTC, URLLC, and autonomous cyberphysical systems. This paper proposes a bottom-up approach to security design, starting from the physical layer, and provides insights into the underlying connections with cryptography. It reviews key topics including secret key generation, wiretap channels, device authentication using PUFs, localization, multi-factor authentication, and jamming attacks at the physical layer. The paper concludes with the authors' aspirations for the 6G security landscape in the era of hyper-connectivity and semantic communications.
IEEE OPEN JOURNAL OF VEHICULAR TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Stefan Roth, Aydin Sezgin, Roman Bessel, H. Vincent Poor
Summary: This article presents a security protocol for ensuring data integrity and system state reliability in wireless sensor networks. Kalman filters are used to predict system state and channel state, and received data is authenticated through hypothesis testing. The article theoretically analyzes the probability of adversaries' success and reliability using chi-square and Gaussian approximations, respectively. The Gaussian approximation is particularly suitable for large-scale single-input multiple-output setups and channel fading.
IEEE OPEN JOURNAL OF VEHICULAR TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Zhiguo Ding, Robert Schober, H. Vincent Poor
Summary: The aim of this paper is to reduce the age of information in wireless networks by utilizing cognitive-radio inspired non-orthogonal multiple access (CR-NOMA) transmission. Two CR-NOMA transmission protocols are developed based on different data generation models, and they are added to a legacy orthogonal multiple access (OMA) network without causing significant disruption. The proposed NOMA protocols provide users with more opportunities to transmit and reduce access delay, which ultimately improve the freshness of data in the wireless network.
IEEE TRANSACTIONS ON COMMUNICATIONS
(2023)
Article
Engineering, Electrical & Electronic
Spilios Evmorfos, Athina P. Petropulu, H. Vincent Poor
Summary: This article investigates the design of an Intelligent Reflecting Surface (IRS) for a Multiple-Input-Single-Output (MISO) communication system in a mobile, spatiotemporally correlated channel environment. The study proposes an actor-critic algorithm that accounts for channel correlations and destination motion, and utilizes a Markov Decision Process (MDP) formulation. The research suggests a framework for designing actor-critic methods for IRS design and addresses the divergence issue caused by including the SNR in the state representation.
IEEE TRANSACTIONS ON SIGNAL PROCESSING
(2023)
