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Circular Polarization Selective Metasurface for Folded Reflectarray Antenna at Ka-band

IEEE Antennas and Wireless Propagation Letters 2025年第5期24卷 1278-1282页

作者： Huang, Heng Ye, Jingxin Xue, Chunhua Li, Teng Guangxi University of Science and Technology Guangxi Key Laboratory of Multidimensional Information Fusion for Intelligent Vehicles School of Electronic Engineering Liuzhou545006 China Southeast University State Key Laboratory of Millimeter Waves School of Information Science and Engineering Nanjing210096 China Purple Mountain Laboratories Nanjing211111 China

A circular polarization (CP) folded reflectarray antenna is proposed at the 30 GHz band. A five-layered circular polarization selective metasurface (CPSM) is introduced to realize the path folding for a CP source. The CPSM element consists of two back-to-back connected CP antennas with a slant I-shaped slot on the ground plane for electromagnetic wave coupling. A 2×2 patch array with a cross-shaped strip embedded in the center is designed for CP response. To enhance angular response stability, square patches are stacked on both the top and bottom sides. A metallic post through all layers is placed in the center to balance the transmission and axial ratio (AR) bandwidth. The proposed CPSM element exhibits superior AR and amplitude performance under larger-angle oblique incidence which promises the folded reflectarray antenna achieves excellent aperture efficiency along with substantial AR and gain bandwidth. To verify the proposed CPSM, a 40×40 folded reflectarray is presented. The measured results show a 3 dB AR bandwidth of 20.3% and a 3 dB gain bandwidth of 15.13%. The peak gain of 33.89 dBic is found at 30 GHz with an aperture efficiency of 60.9%. The remarkable results demonstrate the proposed CPSM for antenna engineering applications. © 2002-2011 IEEE.

关键词： Reflection

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A circuit area optimization of MK-3 S-box

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Cybersecurity 2025年第1期8卷 61-71页

作者： Yanjun Li Weiguo Zhang Yiping Lin Jian Zou Jian Liu Information Industry Information Security Evaluation Center The 15th Research Institute of China Electronic Technology Group CorporationBeijing 100083China Henan Key Laboratory of Network Cryptography Technology Zhengzhou 450001China Beijing Electronic Science and Technology Institute No.7 Fufeng RoadFengtai DistricBeijing 100083China College of Computer and Data Science Fuzhou UniversityFuzhou 350108China

In MILCOM 2015,Kelly et *** the authentication encryption algorithm MK-3,which applied the 16-bit *** paper aims to implement the 16-bit S-box with less circuit ***,we classifed the irreducible polynomials over F_(2n)into three *** we compared the logic gates required for multiplication over the fnite feld constructed by the three types of irreducible *** to the comparison result,we constructed the composite felds, F_((2^(4))^(2))and F_((2^(8))^(2)).Based on the isomorphism of fnite felds,the operations over F_(2)^(16)can be conducted over F_((2^(8))^(2)).Similarly,elements over F28 can be mapped to the corresponding elements over F_((2^(4)))^(2).Next,the SAT solver was used to optimize the operations over smaller feld F_(2)^(4).At last,the architecture of the optimized MK-3 S-box was worked *** with the implementation proposed by the original designer,the circuit area of the MK-3 S-box in this paper is reduced by at least 55.9%.

关键词： irreducible operations optimization

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Novel Sparse Codebook Design for MIMO-SCMA

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IEEE Transactions on Vehicular technology 2025年第5期74卷 8407-8412页

作者： Lei, Tuofeng Luo, Qu Ni, Shuyan Chen, Shimiao Yu, Lisu Xiao, Pei Space Engineering University Key Laboratory of Intelligent Space TTC&O Ministry of Education Beijing101416 China University of Electronic Science and Technology of China National Key Laboratory of Science and Technology on Communications Chengdu610054 China Nanchang University School of Information Engineering Nanchang330031 China Xidian University State Key Laboratory of ISN Xi'an710071 China

The combination of multiple-input multiple-output (MIMO) and sparse code multiple access (SCMA), referred to as MIMO-SCMA, can be leveraged to achieve high spectrum efficiency and provide massive connectivity for future machine -type communication networks. This paper aims to design enhanced sparse codebooks for MIMO-SCMA by jointly combining frequency and spatial diversity over Rayleigh fading channels. First, based on the pairwise error probability (PEP), novel codebook design criteria have been presented, namely the hybrid minimum product distance of the Euclidean distance (MPD-ED) and the minimum Euclidean distance of the superimposed constellation at each frequency element (MED-FE). Then, enhanced mother constellations (MC) are proposed by maximizing the MPD-ED of the MC based on the alternating optimization. Subsequently, the multi-dimensional codebooks are obtained by applying user-specific rotation of the proposed MC to maximize the MED-FE, where the unitary rotations are considered to fully leverage the Euclidean space of the transmit antennas while maintaining the MPD-ED value of the codebook. Finally, numerical results demonstrate that the proposed approach significantly outperforms the state-of-the-art codebooks. © 1967-2012 IEEE.

关键词： Fading channels

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A Consolidated Game Framework for Cooperative Defense Against Cross-Domain Cyber Attacks in Satellite-Enabled Internet of Things

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IEEE Internet of Things Journal 2025年第9期12卷 12853-12868页

作者： Huang, Linan Liu, Peilong Chen, Xu Jiang, Chunxiao Kuang, Linling Lu, Jianhua Tsinghua University Beijing National Research Center for Information Science and Technology Beijing100084 China Tsinghua University Department of Electronic Engineering Beijing100084 China Tsinghua University Beijing National Research Center for Information Science and Technology State Key Laboratory of Space Network and Communications Beijing100084 China Tsinghua University Department of Electronic Engineering State Key Laboratory of Space Network and Communications Beijing100084 China

As the adoption of satellite-enabled Internet of Things (IoT) continues to rise, its intricate multidomain architecture becomes increasingly susceptible to cross-domain cyber threats. Attackers can exploit compromised IoT devices, inject malicious packets into data streams aggregated at the IoT gateway for satellite backhaul, and potentially endanger the satellite network during transmission by exploiting the hardware, software, and protocol vulnerabilities. Compared to single-domain defenses, cooperative defense at the IoT devices, IoT access network, and satellite transmission network provides fine-granularity defense against cross-domain intelligent attacks. However, quantifying cross-domain impacts and tilting incentive misalignment among different participants remain significant challenges, making systematic cooperative defense development a complex task. To address this, we develop a tripartite security game framework to characterize the impacts of attacks and defense methods across both the terrestrial and satellite domains. Leveraging this game model, we devise flow pricing to optimally motivate the IoT network operator (IoT-NO) to prevent malicious packet infiltration into the satellite domain. Subsequently, we propose efficient learning algorithms enabling both the IoT-NO to ascertain their ideal flow sampling strategies and the satellite service provider (SAT-SP) to determine optimal flow pricing. The simulation results corroborate the effectiveness of the consolidated game in counteracting cross-domain cyber attacks and facilitating cooperative defense between the IoT-NO and the SAT-SP with nonaligned incentives. © 2014 IEEE.

关键词： Cyber attacks

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Two efficient beamforming methods for hybrid IRS-aided AF relay wireless networks

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science China(information sciences) 2025年第4期68卷 363-379页

作者： Xuehui WANG Qingbo LI Wen ZHU Feng SHU Mengxing HUANG Fuhui ZHOU Riqing CHEN Cunhua PAN Yongpeng WU Jiangzhou WANG School of Mathematics and Statistics Hainan Normal University Key Laboratory of Data Science and Smart Education Ministry of Education Hainan Normal University School of Information and Communication Engineering Hainan University Collaborative Innovation Center of Information Technology Hainan University School of Electronic and Optical Engineering Nanjing University of Science and Technology College of Electronic and Information Engineering Nanjing University of Aeronautics and Astronautics Digital Fujian Institute of Big Data for Agriculture Fujian Agriculture and Forestry University National Mobile Communications Research Laboratory Southeast University Shanghai Key Laboratory of Navigation and Location Based Services Shanghai Jiao Tong University School of Engineering University of Kent

Owing to its ability to mitigate the double-fading effect by amplifying the reflected signal, the active intelligent reflecting surface(IRS) has garnered significant attention. In this paper, an amplify-and-forward(AF) relay network assisted by a hybrid IRS consisting of both passive and active units is developed. A signal-to-noise ratio(SNR) maximization problem is formulated, where the AF relay beamforming matrix and the hybrid IRS reflecting coefficient matrices for two-time slots need to be optimized. To address the SNR maximization problem, this paper proposes both a high-performance(HP) method and a low-complexity(LC) method. The HP method is based on the semidefinite relaxation and fractional programming(SDR-FP)algorithm, with rank-1 solutions obtained through Gaussian randomization. For the LC method, the amplification coefficient of each active IRS element is assumed to be equal. The SNR maximization problem is then addressed using the whitening filter,generalized power iteration, and generalized Rayleigh-Ritz(WF-GPI-GRR) approach. Simulation results show that compared with the benchmarks, such as the passive IRS-aided AF relay network, the proposed HP-SDR-FP and WF-GPI-GRR methods achieve significant rate improvements. In particular, the HP-SDR-FP and WF-GPI-GRR methods yield more than a 135.0%rate gain when the transmit power Ps of the source is 10 dBm. Furthermore, the proposed HP-SDR-FP method outperforms the WF-GPI-GRR method in terms of rate performance.

关键词： double-fading intelligent reflecting surface active elements passive elements hybrid IRS AF relay

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Determining geocenter motion using combined ground and spaceborne GPS observations with ambiguity resolution

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Advances in Space Research 2025年第11期75卷 7903-7916页

作者： Guo, Shiwei Fan, Lei Li, Zongnan Fang, Xinqi Huo, Chenshu Shi, Chuang School of Space and Earth Sciences Beihang University Beijing102206 China Key Laboratory of Navigation and Communication Fusion Technology Ministry of Industry and Information Technology Beijing100191 China College of Electronic Science National University of Defense Technology Changsha410005 China School of Electronic and Information Engineering Beihang University Beijing100191 China

Owing to the dense global tracking network and the abundant satellites providing continuous observations, the Global Navigation Satellite System (GNSS) has the potential to measure geocenter motion. However, the high altitude of GNSS satellites and the estimation of phase ambiguities compromise the quality of the estimated geocenter coordinates (GCC). This study conducted a combined zero-difference processing of ground observations from 98 global stations and spaceborne observations from four low Earth orbiters (LEOs), investigating the impact of integer ambiguity resolution and LEO configuration on GPS-derived GCC estimates. The ambiguity resolution in the double-difference mode between ground stations and one LEO can significantly improve the observability of GCC estimates, reducing the formal errors by 69.4 %, 69.4 % and 55.0 % for the X, Y and Z components, respectively. The faster relative motion between LEO and GPS satellites contributes to a faster change of tracking geometry. Integrating four LEOs into ground network, the formal errors of GCC parameters are reduced by 77.8 %, 78.2 % and 50.5 % for the X, Y and Z components, respectively. For the most concerned GCC Z component, its correlation with the B1C empirical parameter is reduced from 0.69 to 0.41, demonstrating that the GCC Z component is more separable from the orbital parameters. Besides, the 5th and 7th draconitic harmonics of the Z component are mitigated by 67.0 % and 73.5 %, respectively. The derived annual signal shows a good consistency with the external SLR-based solution, and the amplitude differences are only 0.9 mm, 1.6 mm and 1.2 mm for the X, Y and Z components, respectively. © 2025

关键词： Global positioning system

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Distinct MLT asymmetry of auroral kilometric radiation observed by the FAST satellite

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Earth and Planetary Physics 2025年第1期9卷 188-193页

作者： JiaWen Tang Sai Zhang FuLiang Xiao HongMing Yang Si Liu YiHua He Chang Yang YuYue Jin ZhouKun Deng Ping Li Archie James Johnston School of Physics and Electronic Sciences Changsha University of Science and TechnologyChangsha 410114China Hunan Province Higher Education Key Laboratory of Modeling and Monitoring on the Near-Earth Electromagnetic Environments Changsha University of Science and TechnologyChangsha 410114China School of Electrical and Information Engineering Changsha University of Science and TechnologyChangsha 410114China

Auroral Kilometric Radiation (AKR) is a common radio emission,which can contribute to the magnetosphere-ionosphereatmosphere co u *** emissions have been observed in all magnetic planet magnetospheres of the solar *** this study,using observations from the FAST satellite from 30 August 1996 to 9 September 2001,the distribution of AKR in altitude=500-4500 km and invariant latitude (|ILAT|)=60°-80°has been analyzed.63045 AKR samples have been identified with~48%(52%) samples on the dayside (nightside).Of considerable interest,there is a distinct MLT asymmetry with the high occurrence rate in MLT=05-08 and 18-22(02-05 and 12-17) in the northern (southern) *** distinct MLT asymmetry is associated with the direction of Bxof the interplaneta ry magnetic *** addition,the occurrence rate on the nightside clearly increases as the AE^(*) index *** study further enriches the information and understanding of AKR in the magnetosphere as well as other similar radio emissions.

关键词： asymmetry auroral kilometric radiation interplanetary magnetic field

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Coprime Factorization-Based Encryption and Attack Detection for Nonlinear Cyber-Physical Systems Using Deep Learning Approach

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IEEE Transactions on Automation science and Engineering 2025年 22卷 14020-14029页

作者： Wu, Shimeng Luo, Hao Zhang, Jiusi Qiao, Xinyu Tian, Jilun Jiang, Yuchen Harbin Institute of Technology Department of Control and Simulation Center Harbin150001 China National Key Laboratory ofComplex System Control and Intelligent Agent Cooperation Harbin150001 China University of Electronic Science and Technology of China School of Automation Engineering Chengdu611731 China

This paper presents a data-driven framework for integrating encryption transmission and attack detection in cyber-physical systems (CPS) with nonlinear physical plants. The main focus of this research is to use deep neural networks to realize the coprime factorization (CF) of nonlinear systems. The definition of the CF guides the network training and designing process, and the model’s topology is designed in the state-space form, which improves the interpretability of the data-driven CF. Based on the CF-aided neural networks, an encrypted transmission module is designed that projects information related to system dynamics into a perpendicular data space, which complements existing encryption methods from a control theory perspective. Subsequently, an anomaly detector are designed using the same CF pairs. This detector not only provides high-accuracy detection of attacks but also distinguishes between attacks and faults, thereby reducing the false positive rate and enhancing the reliability of the attack detection. The proposed method has been validated in a real CPS using a mecanum-wheeled vehicle as the physical plant, demonstrating its effectiveness and applicability. © 2004-2012 IEEE.

关键词： Factorization

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RIS-Aided Cell-Free Massive MIMO Systems With Low-Resolution ADCs: Uplink Performance Analysis and Optimization

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IEEE Internet of Things Journal 2025年第11期12卷 18249-18265页

作者： Xiong, Youzhi Tang, Liu Sun, Sanshan Yang, Songjie Liu, Li Mao, Sun Zhang, Zhongpei Wei, Ning Sichuan Normal University Laboratory of Information Intelligent Processing and Communications College of Physics and Electronic Engineering Chengdu610101 China University of Electronic Science and Technology of China National Key Laboratory of Wireless Communications Chengdu611731 China Sichuan Normal University College of Computer Science Chengdu610101 China

This article investigates the uplink performance of reconfigurable intelligent surface (RIS)-aided cell-free (CF) massive multiple-input-multiple-output (mMIMO) systems over spatially correlated Rayleigh fading channels. We consider multiple RISs and low-resolution analog-to-digital converters (ADCs) to improve the system energy efficiency (EE). We first provide an aggregated channel estimation technique with less pilot overhead. By exploiting the statistical channel state information (CSI), we further optimize the RISs’ phase shifts with the goal of minimizing the total normalized mean square error (NMSE) of the estimated aggregated channels. Subsequently, we derive the closed-form expression of the uplink spectral efficiency (SE) for quantization-aware minimum mean-square error (MMSE) combining. Third, based on the closed-form SE expression and power consumption model, we formulate and solve an optimization problem that maximizes the uplink EE under the constraints of transmit power and total ADC quantization bits. Specifically, by leveraging the Dinkelbach transform, Lagrangian dual transform, and fractional programming (FP) techniques, an alternating optimization (AO)-based algorithm is proposed to jointly obtain the bit allocation (BA) scheme among all access points (APs) and the uplink power control (PC) strategy for all users. Finally, numerical results validate the correctness of the closed-form SE expression and show the effectiveness of the proposed optimization methods for phase shift design and EE maximization. © 2014 IEEE.

关键词： Mean square error

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Crystal structure, phase compositions and microwave dielectric properties of Gd1-xCaxV1-xMoxO4 ceramics

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Ceramics International 2025年第15期51卷 20124-20130页

作者： Zhang, Yuheng Chen, Junqi Chen, Jinwu Zhou, Yang Wu, Xiaoyu Tang, Ying Fang, Liang Xiang, Huaicheng College of Physics and Electronic Information Engineering Guilin University of Technology Guilin541004 China Guangxi Universities Key Laboratory of Non-Ferrous Metal Oxide Electronic Functional Materials and Devices Guangxi Key Laboratory of Optical and Electronic Materials and Devices College of Materials Science and Engineering Guilin University of Technology Guilin541004 China School of Mechanical Engineering Guilin University of Aerospace Technology Guilin541004 China

Gd1-xCaxV1-xMoxO4 (0 ≤ x ≤ 1) solid-solution/composite ceramics with low permittivity were synthesized via the solid-state reaction method, and their crystal structures, phase compositions, and microwave dielectric properties were investigated. As the substitution of Ca2+ and Mo6+ increased, phase evolutions were observed: tetragonal zircon (I41/amd) for x 1/a) for x > 0.8. GdVO4, a tetragonal zircon, exhibited a low Εr (11.48) and a near-zero τf (−13.2 ppm/°C), yet its Q × f value is suboptimal (9400 GHz). This limitation stems from its low structural stability, attributed to the prevalent edge-sharing polyhedra and high magnetic susceptibility of Gd. With the increased substitution of Ca2+ and Mo6+, the Q × f value of Gd1-xCaxV1-xMoxO4 ceramics rose to 79,300 GHz (x = 1), while the τf value concurrently dropped to −61.7 ppm/°C. The inherent factors affecting the microwave dielectric properties were determined by Raman scattering and infrared reflection (IR) spectra, dielectric temperature spectrum, magnetic susceptibility, and thermal expansion analysis. © 2025 Elsevier Ltd and Techna Group S.r.l.

关键词： Crystal structure

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