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Dynamic Multi-Target Jamming Channel Allocation and Power Decision-Making in Wireless Communication Networks:A Multi-Agent Deep Reinforcement Learning Approach
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作者 Peng Xiang Xu Hua +4 位作者 Qi Zisen Wang Dan Zhang Yue Rao Ning Gu Wanyi 《China Communications》 2025年第5期71-91,共21页
This paper studies the problem of jamming decision-making for dynamic multiple communication links in wireless communication networks(WCNs).We propose a novel jamming channel allocation and power decision-making(JCAPD... This paper studies the problem of jamming decision-making for dynamic multiple communication links in wireless communication networks(WCNs).We propose a novel jamming channel allocation and power decision-making(JCAPD)approach based on multi-agent deep reinforcement learning(MADRL).In high-dynamic and multi-target aviation communication environments,the rapid changes in channels make it difficult for sensors to accurately capture instantaneous channel state information.This poses a challenge to make centralized jamming decisions with single-agent deep reinforcement learning(DRL)approaches.In response,we design a distributed multi-agent decision architecture(DMADA).We formulate multi-jammer resource allocation as a multiagent Markov decision process(MDP)and propose a fingerprint-based double deep Q-Network(FBDDQN)algorithm for solving it.Each jammer functions as an agent that interacts with the environment in this framework.Through the design of a reasonable reward and training mechanism,our approach enables jammers to achieve distributed cooperation,significantly improving the jamming success rate while considering jamming power cost,and reducing the transmission rate of links.Our experimental results show the FBDDQN algorithm is superior to the baseline methods. 展开更多
关键词 jamming resource allocation JCAPD MADRL wireless communication countermeasure wireless communication networks
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Review for wireless communication technology based on digital encoding metasurfaces
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作者 Haojie Zhan Manna Gu +10 位作者 Ying Tian Huizhen Feng Mingmin Zhu Haomiao Zhou Yongxing Jin Ying Tang Chenxia Li Bo Fang Zhi Hong Xufeng Jing Le Wang 《Opto-Electronic Advances》 2025年第7期51-106,共56页
Metasurfaces offer exceptional capabilities for controlling electromagnetic waves,enabling the realization of unique electromagnetic properties.As communication technology continues to evolve,metasurfaces present prom... Metasurfaces offer exceptional capabilities for controlling electromagnetic waves,enabling the realization of unique electromagnetic properties.As communication technology continues to evolve,metasurfaces present promising applications in wireless communications.This paper reviews the latest advancements in metasurface research within the communication sector,explores metasurface-based wireless relay technologies,and summarizes various wireless communication methods employing different types of metasurfaces across diverse modulation schemes.This paper provides a detailed discussion on the design of wireless communication systems based on coding metasurfaces to simplify transmitter architecture,as well as the development of intelligent coding metasurfaces in the communication field.It also elaborates on the application of vector vortex light fields in metasurface communication.Finally,it offers a forward-looking perspective on wireless communication systems that incorporate coded metasurfaces.This review aims to furnish researchers with a thorough understanding of the current state and future directions of coded metasurface applications in communications. 展开更多
关键词 coding metasurface RIS wireless communications signal modulation TRANSMITTER vortex light
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Mitigating Hotspot Problem Using Northern Goshawk Optimization Based Energy Aware Multi-Hop Communication for Wireless Sensor Networks
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作者 S.Leones Sherwin Vimalraj J.Lydia 《China Communications》 2025年第2期283-298,共16页
Wireless Sensor Network(WSN)comprises a set of interconnected,compact,autonomous,and resource-constrained sensor nodes that are wirelessly linked to monitor and gather data from the physical environment.WSNs are commo... Wireless Sensor Network(WSN)comprises a set of interconnected,compact,autonomous,and resource-constrained sensor nodes that are wirelessly linked to monitor and gather data from the physical environment.WSNs are commonly used in various applications such as environmental monitoring,surveillance,healthcare,agriculture,and industrial automation.Despite the benefits of WSN,energy efficiency remains a challenging problem that needs to be addressed.Clustering and routing can be considered effective solutions to accomplish energy efficiency in WSNs.Recent studies have reported that metaheuristic algorithms can be applied to optimize cluster formation and routing decisions.This study introduces a new Northern Goshawk Optimization with boosted coati optimization algorithm for cluster-based routing(NGOBCO-CBR)method for WSN.The proposed NGOBCO-CBR method resolves the hot spot problem,uneven load balancing,and energy consumption in WSN.The NGOBCO-CBR technique comprises two major processes such as NGO based clustering and BCO-based routing.In the initial phase,the NGObased clustering method is designed for cluster head(CH)selection and cluster construction using five input variables such as residual energy(RE),node proximity,load balancing,network average energy,and distance to BS(DBS).Besides,the NGOBCO-CBR technique applies the BCO algorithm for the optimum selection of routes to BS.The experimental results of the NGOBCOCBR technique are studied under different scenarios,and the obtained results showcased the improved efficiency of the NGOBCO-CBR technique over recent approaches in terms of different measures. 展开更多
关键词 CLUSTERING energy efficiency metaheuristics multihop communication network lifetime wireless sensor networks
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Design and implementation of train-to-train wireless communication in virtual train coupling system
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作者 Weifeng Yang Taifu Chen +2 位作者 Chen Han Dong Feng Jihui Zhou 《High-Speed Railway》 2025年第2期137-144,共8页
This article discusses the detailed examination of the engineering design and implementation process for direct Train-to-Train(T2T)communication within a wireless train backbone network in the context of a virtual cou... This article discusses the detailed examination of the engineering design and implementation process for direct Train-to-Train(T2T)communication within a wireless train backbone network in the context of a virtual coupling scenario.The article proposed several critical aspects,including the optimization of transmission data requirements,which is essential to ensure that communication between trains is efficient and reliable.The design of the T2T wireless communication subsystem is discussed in detail,outlining the technical specifications,protocols,and technologies employed to facilitate wireless communication between multiple trains.Additionally,the article presents a thorough analysis of the data collected during real-world train experiments,highlighting the performance metrics and challenges encountered during testing.This empirical data not only validates the effectiveness of the proposed design but also serves as a crucial reference for future advancements in T2T wireless communication systems.By combining both theoretical principles and practical outcomes,the article offers insights that will aid engineers and researchers in developing robust and efficient wireless communication systems for next-generation train operations. 展开更多
关键词 RAILWAY wireless communication Virtual coupling V2X Train backbone
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High-speed pHEMT-based low noise amplifier for 2.4-GHz wireless communication
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作者 Omar S.Abdulwahid Ahmad N.Abdulfattah +2 位作者 Saad G.Muttlak Mohammadreza Sadeghi Mohamed Missous 《Journal of Electronic Science and Technology》 2025年第4期80-94,共15页
In the era of rapidly expanding wireless technologies,the push for larger spectrum efficiency and better signal integrity has intensified the need for high-efficient and low noise amplifiers(LNAs).A two-stage LNA base... In the era of rapidly expanding wireless technologies,the push for larger spectrum efficiency and better signal integrity has intensified the need for high-efficient and low noise amplifiers(LNAs).A two-stage LNA based on the GaAs/InGaAs pseudomorphic high electron mobility transistor(pHEMT)with a relatively large gate length of 2μm is designed for high-performance 2.4-GHz wireless communication.The I-V characteristic and two-port high-frequency S-parameter of the transistor are measured by on-wafer probing techniques.The results indicate that a discrete transistor with a gate size of 2μm×50μm can provide a maximum transconductance of 16 mS,corresponding to a maximum current-gain cut-off frequency of 7 GHz and maximum oscillation frequency of 8 GHz at the 1-V drain-source voltage.With the impedance matching networks based transmission line technique,an extended integrated layout structure is designed and simulated by using the momentum simulation tool embedded in Advanced Design System,to alleviate the trade-off between noise figure(NF)and gain of the circuit.The findings show that the transistor based on the GaAs/InGaAs technology is capable of delivering high performance with power consumption low to 16 mW,where the maximum simulated gain of 21.5 dB and minimum NF of 2.4 dB are achieved.In terms of linearity,the proposed LNA provides terrific output 1-dB compression of-3 dBm and output third-order intercept point values of 10 dBm.The bandwidth of 0.12 GHz and figure-of-merit of 12 are obtained,which are comparable to that of existing LNAs based on pHEMT.Such a device may benefit to accelerate the development of more robust and power-efficient front-end modules in modern wireless systems,especially for advancing performance-driven applications. 展开更多
关键词 Low noise amplifier Noise figure pHEMT characterization Transistor modeling wireless communication
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Hyper-Chaos and CNN-Based Image Encryption Scheme for Wireless Communication Transmission
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作者 Gang Liu Guosheng Xu +1 位作者 Chenyu Wang Guoai Xu 《Computers, Materials & Continua》 2025年第9期4851-4868,共18页
In wireless communication transmission,image encryption plays a key role in protecting data privacy against unauthorized access.However,conventional encryption methods often face challenges in key space security,parti... In wireless communication transmission,image encryption plays a key role in protecting data privacy against unauthorized access.However,conventional encryption methods often face challenges in key space security,particularly when relying on chaotic sequences,which may exhibit vulnerabilities to brute-force and predictability-based attacks.To address the limitations,this paper presents a robust and efficient encryption scheme that combines iterative hyper-chaotic systems and Convolutional Neural Networks(CNNs).Firstly,a novel two-dimensional iterative hyper-chaotic system is proposed because of its complex dynamic behavior and expanded parameter space,which can enhance the key space complexity and randomness,ensuring resistance against cryptanalysis.Secondly,an innovative CNN architecture is introduced for generating the key stream for the cryptographic system.CNN architecture exhibits excellent nonlinearity and can further optimize the key generation process.To rigorously evaluate the encryption performance,extensive simulation analyses were conducted,including visualization,statistical histogram,information entropy,correlation,differential attack,and resistance.The method has shown a high NPCR(Number of Pixel Change Rate)of 99.642%and a UACI(Unified Average Changing Intensity)value of 33.465%,exhibiting powerful resistance to differential attacks.A series of comprehensive experimental tests have illustrated that the proposed scheme exhibits superior distribution characteristics,which underscores the robustness and efficacy of the image encryption,and helps for communication security. 展开更多
关键词 wireless communication image encryption two-dimensional iterative hyper-chaos convolutional neural network diffusion and scrambling
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Handoff algorithm of high-speed railway wireless communication based on CNN-WaveNet
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作者 ZHAO Rongrong LI Cuiran +1 位作者 XIE Jianli ZHANG Zepeng 《Journal of Measurement Science and Instrumentation》 2025年第1期47-57,共11页
In order to ensure the uninterrupted communication between high-speed train and base station,driving safety and satisfying online experience of passengers,a dual-link switching algorithm based on CNN-WaveNet decision ... In order to ensure the uninterrupted communication between high-speed train and base station,driving safety and satisfying online experience of passengers,a dual-link switching algorithm based on CNN-WaveNet decision parameter multi-step prediction model is proposed to establish a two-hop relay communication system model between the high-speed train and the base station.Firstly,the switching algorithm uses convolution neural network(CNN)to extract the time sequence characteristics of decision parameters.Then,it learns the mapping relationship between feature information and decision parameters based on WaveNet and combining with rolling prediction method to realize multi-step prediction of decision parameters.Finally,dual-antenna communication mode is adopted to realize dual-link communication.The simulation results show that the proposed handover algorithm can improve handover trigger rate and handover success rate. 展开更多
关键词 high-speed railway(HSR) HANDOVER wireless communication convolution neural network(CNN)
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Heterogeneous radio frequency/underwater optical wireless communication relaying systems with MIMO scheme
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作者 Sai Li Liang Yang +1 位作者 Yusheng Sun Qianfen Jiao 《Digital Communications and Networks》 2025年第4期1017-1027,共11页
This paper studies a cooperative relay transmission system within the framework of Multiple-Input Multiple-Output Radio Frequency/Underwater Optical Wireless Communication(MIMO-RF/UOWC),aiming to establish sea-based h... This paper studies a cooperative relay transmission system within the framework of Multiple-Input Multiple-Output Radio Frequency/Underwater Optical Wireless Communication(MIMO-RF/UOWC),aiming to establish sea-based heterogeneous networks.In this setup,the RF links obey κ-μ fading,while the UOWC links undergo the generalized Gamma fading with the pointing error impairments.The relay operates under an Amplify-and-Forward(AF)protocol.Additionally,the attenuation caused by the Absorption and Scattering(AaS)is considered in UOWC links.The work yields precise results for the Average Channel Capacity(ACC),Outage Probability(OP),and average Bit Error Rate(BER).Furthermore,to reveal deeper insights,bounds on the ACC and asymptotic results for the OP and average BER are derived.The findings highlight the superior performance of MIMO-RF/UOWC AF systems compared to Single-Input-Single-Output(SISO)-RF/UOWC AF systems.Various factors affecting the Diversity Gain(DG)of the MIMO-RF/UOWC AF system include the number of antennas/apertures,fading parameters of both links,and pointing error parameters.Moreover,while an increase in the AaS effect can result in significant attenuation,it does not determine the achievable DG of the proposed MIMO-RF/UOWC AF relaying system. 展开更多
关键词 Sea-based heterogeneous networks Underwater wireless optical communication MIMO cooperative systems Absorption and scattering
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Novel optimization techniques for underwater wireless optical communication links:using Monte Carlo simulation
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作者 Intesar Ramley Hamdah MAlzayed +2 位作者 Yas Al-Hadeethi Abeer ZBarasheed Mingguang Chen 《Defence Technology(防务技术)》 2025年第8期386-411,共26页
The Underwater Communication Link(UCL)is a crucial component of Underwater Wireless Optical Communication(UWOC)systems,requiring optimised design to mitigate the high power attenuation inherent in seawater.To ensure t... The Underwater Communication Link(UCL)is a crucial component of Underwater Wireless Optical Communication(UWOC)systems,requiring optimised design to mitigate the high power attenuation inherent in seawater.To ensure the reliability of an optimal UCL design,it is essential to account for the three primary scattering regimes:forward scattering(FSC),backward scattering(BSC),and isotropic scattering(ISC)in seawater channels.This study introduces a new photon-tracking model based on a discrete equation,facilitating Monte Carlo Simulation(MCS)to evaluate how different scattering regimes influence received photon distribution.Three distinct Scattering Regime Contribution Weight(SRCW)probability sets were employed,each representing different UCL operational configurations dominated by specific scattering regimes.The proposed modeling approach enables a comprehensive assessment of the temporal characteristics of received optical pulses,channel loss,and time spread-ultimately defining the optimal UCL design parameters.The key findings of this study include:(1)Enhancing the FSC regime dominance leads to a quasi-light waveguide effect over link spans and small Fields of View(FOV)<25°,significantly improving channel performance in Harbor seawater compared to Coastal seawater.(2)A well-designed UCL with a small FOV(<25°)can minimise channel loss and time spread,ensuring high capacity and efficient performance in both Coastal and Harbor seawaters.(3)When BSC and ISC contributions exceed FSC dominance,the received optical pulse undergoes significant temporal broadening,particularly for larger FOV angles(>25°)and extended link spans.(4)The developed novel MCS-based discrete equation provides a simple yet robust model for simulating photon propagation in both homogeneous and inhomogeneous underwater channels.These insights contribute to developing more efficient and reliable UCL designs with military standards by enhancing UWOC system performance over a longer linkspan for a given limited optical power across various underwater environments. 展开更多
关键词 Channel gain/loss Channel impulse response(CIR) Central limit theorem(CLT) Channel time spread Field of view(FOV) Monte Carlo simulation(MCS) Underwater wireless optical communication(UWOC)
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Distribution algorithm of entangled particles for wireless quantum communication mesh networks
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作者 王霄峻 施丽慧 +2 位作者 占海涛 项睿清 余旭涛 《Journal of Southeast University(English Edition)》 EI CAS 2015年第4期450-456,共7页
With ensured network connectivity in quantum channels, the issue of distributing entangled particles in wireless quantum communication mesh networks can be equivalently regarded as a problem of quantum backbone nodes ... With ensured network connectivity in quantum channels, the issue of distributing entangled particles in wireless quantum communication mesh networks can be equivalently regarded as a problem of quantum backbone nodes selection in order to save cost and reduce complexity. A minimum spanning tree( MST)-based quantum distribution algorithm( QDMST) is presented to construct the mesh backbone network. First, the articulation points are found,and for each connected block uncovered by the articulation points, the general centers are solved. Then, both articulation points and general centers are classified as backbone nodes and an M ST is formed. The quantum path between every two neighbor nodes on the MST is calculated. The nodes on these paths are also classified as backbone nodes. Simulation results validate the advantages of QDMST in the average backbone nodes number and average quantum channel distance compared to the existing random selection algorithm under multiple network scenarios. 展开更多
关键词 wireless quantum communication networks entangled particles distribution wireless mesh networks minimum spanning tree
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Adaptive modulation in MIMO optical wireless communication systems 被引量:1
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作者 吴斌 吴亮 邹采荣 《Journal of Southeast University(English Edition)》 EI CAS 2015年第2期175-180,共6页
In the intensity modulation and direct detection (IM/DD) multiple-input multiple-output (MIMO) optical wireless communication systems, a direct-current-biased adaptive modulation scheme is proposed to guarantee th... In the intensity modulation and direct detection (IM/DD) multiple-input multiple-output (MIMO) optical wireless communication systems, a direct-current-biased adaptive modulation scheme is proposed to guarantee the nonnegative property of transmitted signals, and the MIMO channel is converted to a parallel channel by using a singular value decomposition. Besides, a QR decomposition and successive interference cancellation based adaptive modulation scheme is proposed, and the MIMO channel can be simplified to a parallel channel under the bit error ratio (BER) target constraint. The power is optimally allocated to each sub-channel to maximize the data rate. Simulation results show that the proposed adaptive modulation schemes can effectively improve the transmission rate of the systems under the BER target and constant optical power constraints. The proposed adaptive modulation schemes make use of the multiplexing gain of the MIMO techniques, and can further improve the spectrum efficiency of optical wireless systems. 展开更多
关键词 optical wireless communication multiple inputand multiple output (MIMO) adaptive modulation
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Wireless Communications with Programmable Metasurface:Transceiver Design and Experimental Results 被引量:35
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作者 Wankai Tang Xiang Li +4 位作者 Jun Yan Dai Shi Jin Yong Zeng Qiang Cheng Tie Jun Cui 《China Communications》 SCIE CSCD 2019年第5期46-61,共16页
Metasurfaces have drawn significant attentions due to their superior capability in tailoring electromagnetic waves with a wide frequency range,from microwave to visible light.Recently,programmable metasurfaces have de... Metasurfaces have drawn significant attentions due to their superior capability in tailoring electromagnetic waves with a wide frequency range,from microwave to visible light.Recently,programmable metasurfaces have demonstrated the ability of manipulating the amplitude or phase of electromagnetic waves in a programmable manner in real time,which renders them especially appealing in the applications of wireless communications.In this paper,we present the fundamental principle of applying programmable metasurface as transmitter for wireless communications.Then,we establish a prototype system of metasurface-based transmitter to conduct several experiments and measurements over the air,which practically demonstrate the feasibility of using programmable metasurfaces in future communication systems.By exploiting the dynamically controllable property of programmable metasurface,the design,implementation and experimental evaluation of the proposed metasurface-based wireless communication system are presented with the prototype,which realizes single carrier quadrature phase shift keying(QPSK)transmission over the air.In the developed prototype,the phase of the reflected electromagnetic wave of programma-ble metasurface is directly manipulated in real time according to the baseband control signal,which achieves 2.048 Mbps data transfer rate with video streaming transmission over the air.In addition,experimental result is provided to compare the performance of the proposed metasurface-based architecture against the conventional one.With the slight increase of the transmit power by 5 dB,the same bit error rate(BER)performance can be achieved as the conventional system in the absence of channel coding.Such a result is encouraging considering that the metasurface-based system has the advantages of low hardware cost and simple structure,thus leading to a promising new architecture for wireless communications. 展开更多
关键词 metasurface wireless communication PROTOTYPE system architecture overthe-air measurement
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5G High Mobility Wireless Communications: Challenges and Solutions 被引量:21
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作者 Pingzhi Fan Jing Zhao Chih-Lin I 《China Communications》 SCIE CSCD 2016年第S2期1-13,共13页
The fifth generation(5G) network is expected to support significantly large amount of mobile data traffic and huge number of wireless connections,to achieve better spectrum- and energy-efficiency,as well as quality of... The fifth generation(5G) network is expected to support significantly large amount of mobile data traffic and huge number of wireless connections,to achieve better spectrum- and energy-efficiency,as well as quality of service(QoS) in terms of delay,reliability and security.Furthermore,the 5G network shall also incorporate high mobility requirements as an integral part,providing satisfactory service to users travelling at a speed up to 500 km/h.This paper provides a survey of potential high mobility wireless communication(HMWC) techniques for 5G network.After discussing the typical requirements and challenges of HMWC,key techniques to cope with the challenges are reviewed,including transmission techniques under the fast timevarying channels,network architecture with mobility support,and mobility management.Finally,future research directions on 5G high mobility communications are given. 展开更多
关键词 5G high mobility wireless communications fast time-varying channel network architecture mobility management
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Developing MXenes from Wireless Communication to Electromagnetic Attenuation 被引量:9
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作者 Peng He Mao-Sheng Cao +1 位作者 Wen-Qiang Cao Jie Yuan 《Nano-Micro Letters》 SCIE EI CAS CSCD 2021年第7期188-221,共34页
There is an urgent global need for wireless communication utilizing materials that can provide simultaneous flexibility and high conductivity.Avoiding the harmful effects of electromagnetic(EM)radiation from wireless ... There is an urgent global need for wireless communication utilizing materials that can provide simultaneous flexibility and high conductivity.Avoiding the harmful effects of electromagnetic(EM)radiation from wireless communication is a persistent research hot spot.Two-dimensional(2D)materials are the preferred choice as wireless communication and EM attenuation materials as they are lightweight with high aspect ratios and possess distinguished electronic properties.MXenes,as a novel family of 2D materials,have shown excellent properties in various fields,owing to their excellent electrical conductivity,mechanical stability,high flexibility,and ease of processability.To date,research on the utility of MXenes for wireless communication has been actively pursued.Moreover,MXenes have become the leading materials for EM attenuation.Herein,we systematically review the recent advances in MXene-based materials with different structural designs for wireless communication,electromagnetic interference(EMI)shielding,and EM wave absorption.The relationship governing the structural design and the effectiveness for wireless communication,EMI shielding,and EM wave absorption is clearly revealed.Furthermore,our review mainly focuses on future challenges and guidelines for designing MXene-based materials for industrial application and foundational research. 展开更多
关键词 MXene wireless communication Electromagnetic wave absorption Electromagnetic interference shielding
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Distributed wireless quantum communication networks with partially entangled pairs 被引量:9
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作者 余旭涛 张在琛 徐进 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第1期66-73,共8页
Wireless quantum communication networks transfer quantum state by teleportation. Existing research focuses on maximal entangled pairs. In this paper, we analyse the distributed wireless quantum communication networks ... Wireless quantum communication networks transfer quantum state by teleportation. Existing research focuses on maximal entangled pairs. In this paper, we analyse the distributed wireless quantum communication networks with partially entangled pairs. A quantum routing scheme with multi-hop teleportation is proposed. With the proposed scheme, is not necessary for the quantum path to be consistent with the classical path. The quantum path and its associated classical path are established in a distributed way. Direct multi-hop teleportation is conducted on the selected path to transfer a quantum state from the source to the destination. Based on the feature of multi-hop teleportation using partially entangled pairs, if the node number of the quantum path is even, the destination node will add another teleportation at itself. We simulated the performance of distributed wireless quantum communication networks with a partially entangled state. The probability of transferring the quantum state successfully is statistically analyzed. Our work shows that multi-hop teleportation on distributed wireless quantum networks with partially entangled pairs is feasible. 展开更多
关键词 distributed wireless quantum communication networks partially entangled pairs routing multi-hop teleportation
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Radio Propagation and Wireless Coverage of LSAA-Based 5G Millimeter-Wave Mobile Communication Systems 被引量:14
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作者 Haiming Wang Peize Zhang +1 位作者 Jing Li Xiaohu You 《China Communications》 SCIE CSCD 2019年第5期1-18,共18页
Millimeter-wave(mm Wave) communications will be used in fifth-generation(5G) mobile communication systems, but they experience severe path loss and have high sensitivity to physical objects, leading to smaller cell ra... Millimeter-wave(mm Wave) communications will be used in fifth-generation(5G) mobile communication systems, but they experience severe path loss and have high sensitivity to physical objects, leading to smaller cell radii and complicated network architectures. A coverage extension scheme using large-scale antenna arrays(LSAAs) has been suggested and theoretically proven to be cost-efficient in combination with ultradense small cell networks. To analyze and optimize the LSAA-based network deployments, a comprehensive survey of recent advances in statistical mmWave channel modeling is first presented in terms of channel parameter estimation, large-scale path loss models, and small-scale cluster models. Next, the measurement and modeling results at two 5G candidate mmWave bands(e.g., 28 GHz and 39 GHz) are reviewed and compared in several outdoor scenarios of interest, where the propagation characteristics make crucial contributions to wireless network designs. Finally, the coverage behaviors of systems employing a large number of antenna arrays are discussed, as well as some implications on future mmWave cellular network designs. 展开更多
关键词 FIFTH generation (5G) channel modeling LARGE-SCALE antenna array(LSAA) MILLIMETER wave(mmWave) communicationS radio propagation measurements wireless COVERAGE
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System Performance of Wireless Sensor Network Using LoRa–Zigbee Hybrid Communication 被引量:5
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作者 Van-Truong Truong Anand Nayyar Showkat Ahmad Lone 《Computers, Materials & Continua》 SCIE EI 2021年第8期1615-1635,共21页
Wireless sensor network(WSN)is considered as the fastest growing technology pattern in recent years because of its applicability in varied domains.Many sensor nodes with different sensing functionalities are deployed ... Wireless sensor network(WSN)is considered as the fastest growing technology pattern in recent years because of its applicability in varied domains.Many sensor nodes with different sensing functionalities are deployed in the monitoring area to collect suitable data and transmit it to the gateway.Ensuring communications in heterogeneous WSNs,is a critical issue that needs to be studied.In this research paper,we study the system performance of a heterogeneous WSN using LoRa–Zigbee hybrid communication.Specifically,two Zigbee sensor clusters and two LoRa sensor clusters are used and combined with two Zigbee-to-LoRa converters to communicate in a network managed by a LoRa gateway.The overall system integrates many different sensors in terms of types,communication protocols,and accuracy,which can be used in many applications in realistic environments such as on land,under water,or in the air.In addition to this,a synchronous management software on ThingSpeak Web server and Blynk app is designed.In the proposed system,the token ring protocol in Zigbee network and polling mechanism in LoRa network is used.The system can operate with a packet loss rate of less than 0.5%when the communication range of the Zigbee network is 630 m,and the communication range of the LoRa network is 3.7 km.On the basis of the digital results collected on the management software,this study proves tremendous improvements in the system performance. 展开更多
关键词 wireless sensor network ZIGBEE LoRa communication protocol CONVERTER packet loss
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Channel Estimation and Throughput Evaluation for 5G Wireless Communication Systems in Various Scenarios on High Speed Railways 被引量:7
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作者 yanrong zhao xiyu wang +3 位作者 gongpu wang ruisi he yulong zou zhuyan zhao 《China Communications》 SCIE CSCD 2018年第4期86-97,共12页
The fifth generation (5G) wireless communication is currently a hot research topic and wireless communication systems on high speed railways (HSR) are important applications of 5G technologies. Existing stud- ies ... The fifth generation (5G) wireless communication is currently a hot research topic and wireless communication systems on high speed railways (HSR) are important applications of 5G technologies. Existing stud- ies about 5G wireless systems on high speed railways (HSR) often utilize ideal channel parameters and are usually based on simple scenarios. In this paper, we evaluate the down- link throughput of 5G HSR communication systems on three typical scenarios including urban, cutting and viaduct with three different channel estimators. The channel parameters of each scenario are generated with tapped delay line (TDL) models through ray-tracing sim- ulations, which can be considered as a good match to practical situations. The channel estimators including least square (LS), linear minimum mean square error (LMMSE), and our proposed historical information based ba- sis expansion model (HiBEM). We analyze the performance of the HiBEM estimator in terms of mean square error (MSE) and evaluate the system throughputs with different channel estimates over each scenario. Simulation results are then provided to corroborate our proposed studies. It is shown that our HiBEM estimator outperforms other estimators and that the sys-tem throughput can reach the highest point in the viaduct scenario. 展开更多
关键词 5G channel estimation HSR tapped delay line throughput pertbrmanceanalysis wireless communication.
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Security Issues and Solutions in Wireless Communications at Physical Layer 被引量:4
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作者 吴越 易平 李建华 《China Communications》 SCIE CSCD 2011年第5期11-19,共9页
The properties of broadcast nature, high densities of deployment and severe resource limitations of sensor and mobile networks make wireless networks more vulnerable to various attacks, including modification of messa... The properties of broadcast nature, high densities of deployment and severe resource limitations of sensor and mobile networks make wireless networks more vulnerable to various attacks, including modification of messages, eavesdropping, network intrusion and malicious forwarding. Conventional cryptography-based security may consume significant overhead because of low-power devices, so current research shifts to the wireless physical layer for security enhancement. This paper is mainly focused on security issues and solutions for wireless communications at the physical layer. It first describes the RSSI-based and channel based wireless authentication methods respectively, and presents an overview of various secrecy capacity analyses of fading channel, MIMO channel and cooperative transmission, and then examines different misbehavior detection methods. Finally it draws conclusions and introduces the direction of our future work. 展开更多
关键词 wireless security physical layer AUTHENTICATION SECRECY cooperative communication misbehavior detection
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Wireless communication and wireless power transfer system for implantable medical device 被引量:3
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作者 Zhang Zhang Chao Chen +3 位作者 Tairan Fei Hao Xiao Guangjun Xie Xin Cheng 《Journal of Semiconductors》 EI CAS CSCD 2020年第10期56-62,共7页
Traditional magnetically coupled resonant wireless power transfer technology uses fixed distances between coils for research,to prevent fluctuations in the receiving voltage,and lead to reduce transmission efficiency.... Traditional magnetically coupled resonant wireless power transfer technology uses fixed distances between coils for research,to prevent fluctuations in the receiving voltage,and lead to reduce transmission efficiency.This paper proposes a closed-loop control wireless communication wireless power transfer system with a wearable four-coil structure to stabilize the receiving voltage fluctuation caused by changes in the displacement between the coils.Test results show that the system can provide stable receiving voltage,no matter how the distance between the transmitting coil and the receiving coil is changed.When the transmission distance is 20 mm,the power transfer efficiency of the system can reach 18.5%under the open-loop state,and the stimulus parameters such as the stimulation period and pulse width can be adjusted in real time through the personal computer terminal. 展开更多
关键词 implantable medical equipment four-coil insertion resonance structure wireless communication wireless power transfer
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