In covert communications,joint jammer selection and power optimization are important to improve performance.However,existing schemes usually assume a warden with a known location and perfect Channel State Information(...In covert communications,joint jammer selection and power optimization are important to improve performance.However,existing schemes usually assume a warden with a known location and perfect Channel State Information(CSI),which is difficult to achieve in practice.To be more practical,it is important to investigate covert communications against a warden with uncertain locations and imperfect CSI,which makes it difficult for legitimate transceivers to estimate the detection probability of the warden.First,the uncertainty caused by the unknown warden location must be removed,and the Optimal Detection Position(OPTDP)of the warden is derived which can provide the best detection performance(i.e.,the worst case for a covert communication).Then,to further avoid the impractical assumption of perfect CSI,the covert throughput is maximized using only the channel distribution information.Given this OPTDP based worst case for covert communications,the jammer selection,the jamming power,the transmission power,and the transmission rate are jointly optimized to maximize the covert throughput(OPTDP-JP).To solve this coupling problem,a Heuristic algorithm based on Maximum Distance Ratio(H-MAXDR)is proposed to provide a sub-optimal solution.First,according to the analysis of the covert throughput,the node with the maximum distance ratio(i.e.,the ratio of the distances from the jammer to the receiver and that to the warden)is selected as the friendly jammer(MAXDR).Then,the optimal transmission and jamming power can be derived,followed by the optimal transmission rate obtained via the bisection method.In numerical and simulation results,it is shown that although the location of the warden is unknown,by assuming the OPTDP of the warden,the proposed OPTDP-JP can always satisfy the covertness constraint.In addition,with an uncertain warden and imperfect CSI,the covert throughput provided by OPTDP-JP is 80%higher than the existing schemes when the covertness constraint is 0.9,showing the effectiveness of OPTDP-JP.展开更多
With the boom in maritime activities,the need for highly reliable maritime communication is becoming urgent,which is an important component of 5G/6G communication networks.However,the bandwidth reuse characteristic of...With the boom in maritime activities,the need for highly reliable maritime communication is becoming urgent,which is an important component of 5G/6G communication networks.However,the bandwidth reuse characteristic of 5G/6G networks will inevitably lead to severe interference,resulting in degradation in the communication performance of maritime users.In this paper,we propose a safe deep reinforcement learning based interference coordination scheme to jointly optimize the power control and bandwidth allocation in maritime communication systems,and exploit the quality-of-service requirements of users as the risk value references to evaluate the communication policies.In particular,this scheme designs a deep neural network to select the communication policies through the evaluation network and update the parameters using the target network,which improves the communication performance and speeds up the convergence rate.Moreover,the Nash equilibrium of the interference coordination game and the computational complexity of the proposed scheme are analyzed.Simulation and experimental results verify the performance gain of the proposed scheme compared with benchmarks.展开更多
Frequent extreme disasters have led to frequent large-scale power outages in recent years.To quickly restore power,it is necessary to understand the damage information of the distribution network accurately.However,th...Frequent extreme disasters have led to frequent large-scale power outages in recent years.To quickly restore power,it is necessary to understand the damage information of the distribution network accurately.However,the public network communication system is easily damaged after disasters,causing the operation center to lose control of the distribution network.In this paper,we considered using satellites to transmit the distribution network data and focus on the resource scheduling problem of the satellite emergency communication system for the distribution network.Specifically,this paper first formulates the satellite beam-pointing problem and the accesschannel joint resource allocation problem.Then,this paper proposes the Priority-based Beam-pointing and Access-Channel joint optimization algorithm(PBAC),which uses convex optimization theory to solve the satellite beam pointing problem,and adopts the block coordinate descent method,Lagrangian dual method,and a greedy algorithm to solve the access-channel joint resource allocation problem,thereby obtaining the optimal resource scheduling scheme for the satellite network.Finally,this paper conducts comparative experiments with existing methods to verify the effec-tiveness of the proposed methods.The results show that the total weighted transmitted data of the proposed algorithm is increased by about 19.29∼26.29%compared with other algorithms.展开更多
Digital infrastructure possesses dual attributes as both an international public good and a strategic communication tool for major countries. In recent years, the US has been active in the field of global digital infr...Digital infrastructure possesses dual attributes as both an international public good and a strategic communication tool for major countries. In recent years, the US has been active in the field of global digital infrastructure, showing a trend of deep coupling and mutual embedding with strategic communication. The US has built a strategic communication system for digital infrastructure. This system is designed to set the international agenda, collect information and intelligence, and deter its competitors. The system presents a three-way coherent infrastructure of a basic layer, application layer,and value layer. The mode of operation is characterized by commercial force collaboration, alliance system linkage, and global multi-domain network layout. However, to maintain its unipolar digital hegemony,the United States has over-instrumentalized its digital infrastructure and exploited and amplified the asymmetry of digital science and technology for a long period of time, which not only highlights its unilateral stance and exclusionary nature but also results in a global digital divide and trust deficit, which will pose constraints on its sustainability in the long term.展开更多
Communications system has a signifi-cant impact on both operational safety and logisti-cal efficiency within low-altitude drone logistics net-works.Aiming at providing a systematic investiga-tion of real-world communi...Communications system has a signifi-cant impact on both operational safety and logisti-cal efficiency within low-altitude drone logistics net-works.Aiming at providing a systematic investiga-tion of real-world communication requirements and challenges encountered in Meituan UAV’s daily oper-ations,this article first introduces the operational sce-narios within current drone logistics networks and an-alyzes the related communication requirements.Then,the current communication solution and its inherent bottlenecks are elaborated.Finally,this paper explores emerging technologies and examines their application prospects in drone logistics networks.展开更多
Meteor Burst Communication(MBC),a niche yet revolutionary wireless communication paradigm,exploits the transient ionized trails generated by meteors ablating in Earth’s atmosphere to enable sporadic yet resilient lon...Meteor Burst Communication(MBC),a niche yet revolutionary wireless communication paradigm,exploits the transient ionized trails generated by meteors ablating in Earth’s atmosphere to enable sporadic yet resilient long-distance radio links.Known for its exceptional resilience,robustness,and sustained connectivity,MBC holds significant promise for applications in emergency communications,remote area connectivity,military/defense systems,and environmental monitoring.However,the scientific exploration and application of MBC have long been highly challenging.In particular,under the combined influence of multiple physical field factors,the channel experiences superimposed multiple random fading effects,exhibiting bursty,highly time-varying,and strongly random characteristics.This persistent technical challenge has resulted in the absence of a practical statistical channel model for MBC to date.展开更多
Low earth orbit(LEO)satellite communication which can provide global wireless ser-vice plays a critical role in the future wireless communication networks.However,due to the high speed of satellite motion,numerous nar...Low earth orbit(LEO)satellite communication which can provide global wireless ser-vice plays a critical role in the future wireless communication networks.However,due to the high speed of satellite motion,numerous narrow beams,and complex satellite-terrestrial channels,the initial access between the LEO satellites and user terminals(UEs)becomes more complicated.To establish a stable link,a beam search is required between the satellite and the UE.However,tradi-tional beam search methods(e.g.,exhaustive search)have high time complexity which is not suit-able in high-speed scenarios.Therefore,in this paper,a sensing-aided hierarchical beam search method is proposed,which is performed in two stages.In the first stage,wide beam scanning is per-formed to find the optimal angular range.In the second stage,after determining the directions of narrow beams via sensing the direction of arrival(DOA)of satellite signals,the narrow beams gen-erated at estimated directions are used to sweep the satellite beams.This method can help fast beam alignment and obtain high beam search accuracy,which is verified by simulation results.Moreover,we analyze the gain of beam alignment from the two-stage beam search method.展开更多
Remit of Journal ZTE Communications publishes original theoretical papers,research findings,and surveys on a broad range of communications topics,including communications and information system design,optical fiber an...Remit of Journal ZTE Communications publishes original theoretical papers,research findings,and surveys on a broad range of communications topics,including communications and information system design,optical fiber and electro-optical engineering,microwave technology,radio wave propagation,antenna engineering,electromagnetics,signal and image processing,and power engineering.The journal is designed to be an integrated forum for university academics and industry researchers from around the world.展开更多
Generative artificial intelligence(AI),as an emerging paradigm in content generation,has demonstrated its great potentials in creating high-fidelity data including images,texts,and videos.Nowadays wireless networks an...Generative artificial intelligence(AI),as an emerging paradigm in content generation,has demonstrated its great potentials in creating high-fidelity data including images,texts,and videos.Nowadays wireless networks and applications have been rapidly evolving from achieving“connected things”to embracing“connected intelligence”.展开更多
Dear Editor,Industrial Internet of things(IIoT) is a typical application of cyberphysical system(CPS). In the IIoT, wireless communication is an inevitable trend to replace the deployment-limited wired transmission fo...Dear Editor,Industrial Internet of things(IIoT) is a typical application of cyberphysical system(CPS). In the IIoT, wireless communication is an inevitable trend to replace the deployment-limited wired transmission for cases with large-scale and mobile devices. However, wireless communication gives rise to critical issues related to physical security, such as malicious detections and attacks [1].展开更多
This paper investigates the reconfigurable intelligent surface(RIS)-aided MIMO covert communications in high-speed railway(HSR)scenario.In the scenario,RIS controls the phases of reflection elements dynamically to sen...This paper investigates the reconfigurable intelligent surface(RIS)-aided MIMO covert communications in high-speed railway(HSR)scenario.In the scenario,RIS controls the phases of reflection elements dynamically to send the signal in the desired direction,which facilitates the covert communication between base station(BS)and train mobile relay(MR)in the existence of a watchful warden(Willie).To protect the desired transmission,it is assumed that MR sends out jamming signals with a varying power to confuse the Willie.Considering the Doppler spread caused by the time-varying wireless channel,the joint optimization problem of the BS beamforming matrix,MR beamforming matrix,and the RIS phase shifts is established to maximize the covert throughput.An alternating optimization(AO)method for handling non convex problems is proposed based on coupling effects and the constraints of constant modulus,and a semidefinite relaxation method is provided.Finally,we achieve the optimal solutions of the multi-objective optimization problem by interior-point method.The simulation results demonstrate that the proposed algorithm exhibits the superior robustness and covert performances in high-speed railway scenarios.展开更多
A thin compact broadband coplanarfed rectangular-ring monopole antenna parasiticallyloaded by three nested concentric rectangle rings and aπ-shaped stub is proposed suitable for modern communication needs.It has an o...A thin compact broadband coplanarfed rectangular-ring monopole antenna parasiticallyloaded by three nested concentric rectangle rings and aπ-shaped stub is proposed suitable for modern communication needs.It has an overall area of only 25 mm×6 mm(0.29λ_(0)×0.07λ_(0)at 3.5 GHz),which can be the base radiating element of the MIMO array,being easily integrated into any wireless device.Its measured(simulated)fractional bandwidth is 24.6%(31.6%)ranging from 3.25(3.09)to 4.16(4.25)GHz,being applicable to the 5G N48,N77,and N78 bands.Practical guidelines are also provided to make the proposed design operate on some other additional 5G bands(e.g.,N41 or N46)without compromising its overall size.As far as the radiation properties are concerned,the antenna with such small dimensions radiates nearly bidirectionally and omnidirectionally in the E-and H-plane,respectively,and has an average measured(simulated)peak realized gain of-0.1(1.8)dBi over the band of interest.The proposed antenna is wideband,physically small and relatively easy to manufacture,making it straightforward to integrate with the RF electronics in IoT sensors.展开更多
In recent years,deep learning-based semantic communications have shown great potential to enhance the performance of communication systems.This has led to the belief that semantic communications represent a breakthrou...In recent years,deep learning-based semantic communications have shown great potential to enhance the performance of communication systems.This has led to the belief that semantic communications represent a breakthrough beyond the Shannon paradigm and will play an essential role in future communications.To narrow the gap between current research and future vision,after an overview of semantic communications,this article presents and discusses ten fundamental and critical challenges in today’s semantic communication field.These challenges are divided into theory foundation,system design,and practical implementation.Challenges related to the theory foundation including semantic capacity,entropy,and rate-distortion are discussed first.Then,the system design challenges encompassing architecture,knowledge base,joint semantic-channel coding,tailored transmission scheme,and impairment are posed.The last two challenges associated with the practical implementation lie in cross-layer optimization for networks and standardization.For each challenge,efforts to date and thoughtful insights are provided.展开更多
Advancements in mode-division multiplexing(MDM)techniques,aimed at surpassing the Shannon limit and augmenting transmission capacity,have garnered significant attention in optical fiber communica-tion,propelling the d...Advancements in mode-division multiplexing(MDM)techniques,aimed at surpassing the Shannon limit and augmenting transmission capacity,have garnered significant attention in optical fiber communica-tion,propelling the demand for high-quality multiplexers and demultiplexers.However,the criteria for ideal-mode multiplexers/demultiplexers,such as performance,scalability,compatibility,and ultra-compactness,have only partially been achieved using conventional bulky devices(e.g.,waveguides,grat-ings,and free space optics)—an issue that will substantially restrict the application of MDM techniques.Here,we present a neuro-meta-router(NMR)optimized through deep learning that achieves spatial multi-mode division and supports multi-channel communication,potentially offering scalability,com-patibility,and ultra-compactness.An MDM communication system based on an NMR is theoretically designed and experimentally demonstrated to enable simultaneous and independent multi-dataset transmission,showcasing a capacity of up to 100 gigabits per second(Gbps)and a symbol error rate down to the order of 104,all achieved without any compensation technologies or correlation devices.Our work presents a paradigm that merges metasurfaces,fiber communications,and deep learning,with potential applications in intelligent metasurface-aided optical interconnection,as well as all-optical pat-tern recognition and classification.展开更多
Orbital angular momentum(OAM)can achieve multifold increase of spectrum efficiency,but the hollow divergence characteristic and Line-of-Sight(LoS)path requirement impose the crucial challenges for vortex wave communic...Orbital angular momentum(OAM)can achieve multifold increase of spectrum efficiency,but the hollow divergence characteristic and Line-of-Sight(LoS)path requirement impose the crucial challenges for vortex wave communications.For air-to-ground vortex wave communications,where there exists the LoS path,this paper proposes a multi-user cooperative receive(MUCR)scheme to break through the communication distance limitation caused by the characteristic of vortex wave hollow divergence.In particular,we derive the optimal radial position corresponding to the maximum intensity,which is used to adjust the waist radius.Based on the waist radius and energy ring,the cooperative ground users having the minimum angular square difference are selected.Also,the signal compensation scheme is proposed to decompose OAM signals in air-to-ground vortex wave communications.Simulation results are presented to verify the superiority of our proposed MUCR scheme.展开更多
The rapid evolution of Fifth-Generation(5G)networks and the strategic development of Sixth-Generation(6G)technologies have significantly advanced the implementation of air-ground integrated networks with seamless cove...The rapid evolution of Fifth-Generation(5G)networks and the strategic development of Sixth-Generation(6G)technologies have significantly advanced the implementation of air-ground integrated networks with seamless coverage.Unmanned Aerial Vehicles(UAVs),serving as high-mobility aerial platforms,are extensively utilized to enhance coverage in long-distance emergency communication scenarios.The resource-constrained communication environments in emergencies by classifying UAVs into swarm UAVs and relay UAVs as aerial communication nodes is inversitgated.A horizontal deployment strategy for swarm UAVs is formulated through K-means clustering algorithm optimization,while a vertical deployment scheme is established using convex optimization methods.The minimum-path trajectory planning for relay UAVs is optimized via the Particle Swarm Optimization(PSO)algorithm,enhancing communication reliability between UAV swarms and terrestrial base stations.A three-dimensional heterogeneous network architecture is realized by modeling spatial multi-hop relay links.Experimental results demonstrate that the proposed joint UAV relay optimization framework outperforms conventional algorithms in both coverage performance and relay capability during video stream transmission,achieving significant improvements in coverage enhancement and relay efficiency.This work provides technical foundations for constructing high-reliability air-ground cooperative systems in emergency communications.展开更多
In offshore maritime communication sys-tems,base stations(BSs)are employed along the coastline to provide high-speed data service for ves-sels in coastal sea areas.To ensure the line-of-sight propagation of BS-vessel ...In offshore maritime communication sys-tems,base stations(BSs)are employed along the coastline to provide high-speed data service for ves-sels in coastal sea areas.To ensure the line-of-sight propagation of BS-vessel links,high transceiver an-tenna height is required,which limits the number of geographically available sites for BS deployment,and imposes a high cost for realizing effective wide-area coverage.In this paper,the joint user association and power allocation(JUAPA)problem is investigated to enhance the coverage of offshore maritime systems.By exploiting the characteristics of network topology as well as vessels’motion in offshore communica-tions,a multi-period JUAPA problem is formulated to maximize the number of ships that can be simultane-ously served by the network.This JUAPA problem is intrinsically non-convex and subject to mixed-integer constraints,which is difficult to solve either analyt-ically or numerically.Hence,we propose an iterative augmentation based framework to efficiently select the active vessels,where the JUAPA scheme is iteratively optimized by the network for increasing the number of the selected vessels.More specifically,in each itera-tion,the user association variables and power alloca-tion variables are determined by solving two separate subproblems,so that the JUAPA strategy can be up-dated in a low-complexity manner.The performance of the proposed JUAPA method is evaluated by exten-sive simulation,and numerical results indicate that it can effectively increase the number of vessels served by the network,and thus enhances the coverage of off-shore systems.展开更多
To address the contradiction between the explosive growth of wireless data and the limited spectrum resources,semantic communication has been emerging as a promising communication paradigm.In this paper,we thus design...To address the contradiction between the explosive growth of wireless data and the limited spectrum resources,semantic communication has been emerging as a promising communication paradigm.In this paper,we thus design a speech semantic coded communication system,referred to as Deep-STS(i.e.,Deep-learning based Speech To Speech),for the lowbandwidth speech communication.Specifically,we first deeply compress the speech data through extracting the textual information from the speech based on the conformer encoder and connectionist temporal classification decoder at the transmitter side of Deep-STS system.In order to facilitate the final speech timbre recovery,we also extract the short-term timbre feature of speech signals only for the starting 2s duration by the long short-term memory network.Then,the Reed-Solomon coding and hybrid automatic repeat request protocol are applied to improve the reliability of transmitting the extracted text and timbre feature over the wireless channel.Third,we reconstruct the speech signal by the mel spectrogram prediction network and vocoder,when the extracted text is received along with the timbre feature at the receiver of Deep-STS system.Finally,we develop the demo system based on the USRP and GNU radio for the performance evaluation of Deep-STS.Numerical results show that the ac-Received:Jan.17,2024 Revised:Jun.12,2024 Editor:Niu Kai curacy of text extraction approaches 95%,and the mel cepstral distortion between the recovered speech signal and the original one in the spectrum domain is less than 10.Furthermore,the experimental results show that the proposed Deep-STS system can reduce the total delay of speech communication by 85%on average compared to the G.723 coding at the transmission rate of 5.4 kbps.More importantly,the coding rate of the proposed Deep-STS system is extremely low,only 0.2 kbps for continuous speech communication.It is worth noting that the Deep-STS with lower coding rate can support the low-zero-power speech communication,unveiling a new era in ultra-efficient coded communications.展开更多
Remote driving,an emergent technology enabling remote operations of vehicles,presents a significant challenge in transmitting large volumes of image data to a central server.This requirement outpaces the capacity of t...Remote driving,an emergent technology enabling remote operations of vehicles,presents a significant challenge in transmitting large volumes of image data to a central server.This requirement outpaces the capacity of traditional communication methods.To tackle this,we propose a novel framework using semantic communications,through a region of interest semantic segmentation method,to reduce the communication costs by transmitting meaningful semantic information rather than bit-wise data.To solve the knowledge base inconsistencies inherent in semantic communications,we introduce a blockchain-based edge-assisted system for managing diverse and geographically varied semantic segmentation knowledge bases.This system not only ensures the security of data through the tamper-resistant nature of blockchain but also leverages edge computing for efficient management.Additionally,the implementation of blockchain sharding handles differentiated knowledge bases for various tasks,thus boosting overall blockchain efficiency.Experimental results show a great reduction in latency by sharding and an increase in model accuracy,confirming our framework's effectiveness.展开更多
With the rapid growth of the low-altitude economy,the demand for typical low-altitude ap-plications has accelerated the advancement of inte-grated sensing and communications(ISAC)networks.This paper begins by analyzin...With the rapid growth of the low-altitude economy,the demand for typical low-altitude ap-plications has accelerated the advancement of inte-grated sensing and communications(ISAC)networks.This paper begins by analyzing representative ap-plication scenarios to clarify the core requirements of the low-altitude economy for modern ISAC net-works.By investigating the distinctive characteris-tics of ISAC networks in low-altitude environments,it presents a comprehensive analysis of key challenges and identifies four major issues:challenges in pre-cise target detection,interference management,in-consistent sensing and communication coverage,and the complexity of air-ground coordination and han-dover.Based on fundamental theories and principles,the paper proposes corresponding solutions,encom-passing advanced technologies for precise target de-tection and recognition,high-reliability networked de-tection,robust interference management,and seamless air-ground collaboration.These solutions aim to es-tablish a solid foundation for the future development of intelligent low-altitude networks and ensure effec-tive support for emerging applications.展开更多
基金supported by the CAS Project for Young Scientists in Basic Research under Grant YSBR-035Jiangsu Provincial Key Research and Development Program under Grant BE2021013-2.
文摘In covert communications,joint jammer selection and power optimization are important to improve performance.However,existing schemes usually assume a warden with a known location and perfect Channel State Information(CSI),which is difficult to achieve in practice.To be more practical,it is important to investigate covert communications against a warden with uncertain locations and imperfect CSI,which makes it difficult for legitimate transceivers to estimate the detection probability of the warden.First,the uncertainty caused by the unknown warden location must be removed,and the Optimal Detection Position(OPTDP)of the warden is derived which can provide the best detection performance(i.e.,the worst case for a covert communication).Then,to further avoid the impractical assumption of perfect CSI,the covert throughput is maximized using only the channel distribution information.Given this OPTDP based worst case for covert communications,the jammer selection,the jamming power,the transmission power,and the transmission rate are jointly optimized to maximize the covert throughput(OPTDP-JP).To solve this coupling problem,a Heuristic algorithm based on Maximum Distance Ratio(H-MAXDR)is proposed to provide a sub-optimal solution.First,according to the analysis of the covert throughput,the node with the maximum distance ratio(i.e.,the ratio of the distances from the jammer to the receiver and that to the warden)is selected as the friendly jammer(MAXDR).Then,the optimal transmission and jamming power can be derived,followed by the optimal transmission rate obtained via the bisection method.In numerical and simulation results,it is shown that although the location of the warden is unknown,by assuming the OPTDP of the warden,the proposed OPTDP-JP can always satisfy the covertness constraint.In addition,with an uncertain warden and imperfect CSI,the covert throughput provided by OPTDP-JP is 80%higher than the existing schemes when the covertness constraint is 0.9,showing the effectiveness of OPTDP-JP.
文摘With the boom in maritime activities,the need for highly reliable maritime communication is becoming urgent,which is an important component of 5G/6G communication networks.However,the bandwidth reuse characteristic of 5G/6G networks will inevitably lead to severe interference,resulting in degradation in the communication performance of maritime users.In this paper,we propose a safe deep reinforcement learning based interference coordination scheme to jointly optimize the power control and bandwidth allocation in maritime communication systems,and exploit the quality-of-service requirements of users as the risk value references to evaluate the communication policies.In particular,this scheme designs a deep neural network to select the communication policies through the evaluation network and update the parameters using the target network,which improves the communication performance and speeds up the convergence rate.Moreover,the Nash equilibrium of the interference coordination game and the computational complexity of the proposed scheme are analyzed.Simulation and experimental results verify the performance gain of the proposed scheme compared with benchmarks.
基金supported by the Science and Technology Project of the State Grid Corporation of China(5400-202255158A-1-1-ZN).
文摘Frequent extreme disasters have led to frequent large-scale power outages in recent years.To quickly restore power,it is necessary to understand the damage information of the distribution network accurately.However,the public network communication system is easily damaged after disasters,causing the operation center to lose control of the distribution network.In this paper,we considered using satellites to transmit the distribution network data and focus on the resource scheduling problem of the satellite emergency communication system for the distribution network.Specifically,this paper first formulates the satellite beam-pointing problem and the accesschannel joint resource allocation problem.Then,this paper proposes the Priority-based Beam-pointing and Access-Channel joint optimization algorithm(PBAC),which uses convex optimization theory to solve the satellite beam pointing problem,and adopts the block coordinate descent method,Lagrangian dual method,and a greedy algorithm to solve the access-channel joint resource allocation problem,thereby obtaining the optimal resource scheduling scheme for the satellite network.Finally,this paper conducts comparative experiments with existing methods to verify the effec-tiveness of the proposed methods.The results show that the total weighted transmitted data of the proposed algorithm is increased by about 19.29∼26.29%compared with other algorithms.
基金a phased achievement of a major project of the National Social Science Fund of China,titled “Research on the Security Impact of the Situation in the Bay of Bengal Region on China’s East Data West Computing Project”(Project No.:22ZDA181)。
文摘Digital infrastructure possesses dual attributes as both an international public good and a strategic communication tool for major countries. In recent years, the US has been active in the field of global digital infrastructure, showing a trend of deep coupling and mutual embedding with strategic communication. The US has built a strategic communication system for digital infrastructure. This system is designed to set the international agenda, collect information and intelligence, and deter its competitors. The system presents a three-way coherent infrastructure of a basic layer, application layer,and value layer. The mode of operation is characterized by commercial force collaboration, alliance system linkage, and global multi-domain network layout. However, to maintain its unipolar digital hegemony,the United States has over-instrumentalized its digital infrastructure and exploited and amplified the asymmetry of digital science and technology for a long period of time, which not only highlights its unilateral stance and exclusionary nature but also results in a global digital divide and trust deficit, which will pose constraints on its sustainability in the long term.
基金supported by Shenzhen Science and Technology Program(KJZD20230923115210021)。
文摘Communications system has a signifi-cant impact on both operational safety and logisti-cal efficiency within low-altitude drone logistics net-works.Aiming at providing a systematic investiga-tion of real-world communication requirements and challenges encountered in Meituan UAV’s daily oper-ations,this article first introduces the operational sce-narios within current drone logistics networks and an-alyzes the related communication requirements.Then,the current communication solution and its inherent bottlenecks are elaborated.Finally,this paper explores emerging technologies and examines their application prospects in drone logistics networks.
文摘Meteor Burst Communication(MBC),a niche yet revolutionary wireless communication paradigm,exploits the transient ionized trails generated by meteors ablating in Earth’s atmosphere to enable sporadic yet resilient long-distance radio links.Known for its exceptional resilience,robustness,and sustained connectivity,MBC holds significant promise for applications in emergency communications,remote area connectivity,military/defense systems,and environmental monitoring.However,the scientific exploration and application of MBC have long been highly challenging.In particular,under the combined influence of multiple physical field factors,the channel experiences superimposed multiple random fading effects,exhibiting bursty,highly time-varying,and strongly random characteristics.This persistent technical challenge has resulted in the absence of a practical statistical channel model for MBC to date.
基金supported in part by Chongqing Natural Science Foundation Innovation and Development Joint Fund(No.CSTB2024NSCQ-LMX0024)in part by Shanghai Natu-ral Science Foundation(No.24ZR1421800)。
文摘Low earth orbit(LEO)satellite communication which can provide global wireless ser-vice plays a critical role in the future wireless communication networks.However,due to the high speed of satellite motion,numerous narrow beams,and complex satellite-terrestrial channels,the initial access between the LEO satellites and user terminals(UEs)becomes more complicated.To establish a stable link,a beam search is required between the satellite and the UE.However,tradi-tional beam search methods(e.g.,exhaustive search)have high time complexity which is not suit-able in high-speed scenarios.Therefore,in this paper,a sensing-aided hierarchical beam search method is proposed,which is performed in two stages.In the first stage,wide beam scanning is per-formed to find the optimal angular range.In the second stage,after determining the directions of narrow beams via sensing the direction of arrival(DOA)of satellite signals,the narrow beams gen-erated at estimated directions are used to sweep the satellite beams.This method can help fast beam alignment and obtain high beam search accuracy,which is verified by simulation results.Moreover,we analyze the gain of beam alignment from the two-stage beam search method.
文摘Remit of Journal ZTE Communications publishes original theoretical papers,research findings,and surveys on a broad range of communications topics,including communications and information system design,optical fiber and electro-optical engineering,microwave technology,radio wave propagation,antenna engineering,electromagnetics,signal and image processing,and power engineering.The journal is designed to be an integrated forum for university academics and industry researchers from around the world.
文摘Generative artificial intelligence(AI),as an emerging paradigm in content generation,has demonstrated its great potentials in creating high-fidelity data including images,texts,and videos.Nowadays wireless networks and applications have been rapidly evolving from achieving“connected things”to embracing“connected intelligence”.
基金partly supported by the National Natural Science Foundation of China(62273298,62273295)Hebei Natural Science Foundation(F2023203063,F2022203025)+1 种基金China Scholarship Council(CSC)(202308130180)Provincial Key Laboratory Performance Subsidy Project(22567612H)
文摘Dear Editor,Industrial Internet of things(IIoT) is a typical application of cyberphysical system(CPS). In the IIoT, wireless communication is an inevitable trend to replace the deployment-limited wired transmission for cases with large-scale and mobile devices. However, wireless communication gives rise to critical issues related to physical security, such as malicious detections and attacks [1].
基金supported by the National Natural Science Foundation of China(62161016)the Key Research and Development Project of Lanzhou Jiaotong University(ZDYF2304)the Beijing Engineering Research Center of High-Speed Railway Broadband Mobile Communications(BHRC-2022-1),Beijing Jiaotong University.
文摘This paper investigates the reconfigurable intelligent surface(RIS)-aided MIMO covert communications in high-speed railway(HSR)scenario.In the scenario,RIS controls the phases of reflection elements dynamically to send the signal in the desired direction,which facilitates the covert communication between base station(BS)and train mobile relay(MR)in the existence of a watchful warden(Willie).To protect the desired transmission,it is assumed that MR sends out jamming signals with a varying power to confuse the Willie.Considering the Doppler spread caused by the time-varying wireless channel,the joint optimization problem of the BS beamforming matrix,MR beamforming matrix,and the RIS phase shifts is established to maximize the covert throughput.An alternating optimization(AO)method for handling non convex problems is proposed based on coupling effects and the constraints of constant modulus,and a semidefinite relaxation method is provided.Finally,we achieve the optimal solutions of the multi-objective optimization problem by interior-point method.The simulation results demonstrate that the proposed algorithm exhibits the superior robustness and covert performances in high-speed railway scenarios.
文摘A thin compact broadband coplanarfed rectangular-ring monopole antenna parasiticallyloaded by three nested concentric rectangle rings and aπ-shaped stub is proposed suitable for modern communication needs.It has an overall area of only 25 mm×6 mm(0.29λ_(0)×0.07λ_(0)at 3.5 GHz),which can be the base radiating element of the MIMO array,being easily integrated into any wireless device.Its measured(simulated)fractional bandwidth is 24.6%(31.6%)ranging from 3.25(3.09)to 4.16(4.25)GHz,being applicable to the 5G N48,N77,and N78 bands.Practical guidelines are also provided to make the proposed design operate on some other additional 5G bands(e.g.,N41 or N46)without compromising its overall size.As far as the radiation properties are concerned,the antenna with such small dimensions radiates nearly bidirectionally and omnidirectionally in the E-and H-plane,respectively,and has an average measured(simulated)peak realized gain of-0.1(1.8)dBi over the band of interest.The proposed antenna is wideband,physically small and relatively easy to manufacture,making it straightforward to integrate with the RF electronics in IoT sensors.
基金supported in part by the National Key Research and Development Program of China under Grant 2021YFA1000500(4)in part by the Natural Science Foundation of China(NSFC)under Grant 62293484,Grant U22B2001,Grant 62425110,Grant 62227801,Grant 62442106.
文摘In recent years,deep learning-based semantic communications have shown great potential to enhance the performance of communication systems.This has led to the belief that semantic communications represent a breakthrough beyond the Shannon paradigm and will play an essential role in future communications.To narrow the gap between current research and future vision,after an overview of semantic communications,this article presents and discusses ten fundamental and critical challenges in today’s semantic communication field.These challenges are divided into theory foundation,system design,and practical implementation.Challenges related to the theory foundation including semantic capacity,entropy,and rate-distortion are discussed first.Then,the system design challenges encompassing architecture,knowledge base,joint semantic-channel coding,tailored transmission scheme,and impairment are posed.The last two challenges associated with the practical implementation lie in cross-layer optimization for networks and standardization.For each challenge,efforts to date and thoughtful insights are provided.
基金supported by the National Key Research and Development Program of China(2023YFB2804704)the National Natural Science Foundation of China(12174292,12374278,and 62105250).
文摘Advancements in mode-division multiplexing(MDM)techniques,aimed at surpassing the Shannon limit and augmenting transmission capacity,have garnered significant attention in optical fiber communica-tion,propelling the demand for high-quality multiplexers and demultiplexers.However,the criteria for ideal-mode multiplexers/demultiplexers,such as performance,scalability,compatibility,and ultra-compactness,have only partially been achieved using conventional bulky devices(e.g.,waveguides,grat-ings,and free space optics)—an issue that will substantially restrict the application of MDM techniques.Here,we present a neuro-meta-router(NMR)optimized through deep learning that achieves spatial multi-mode division and supports multi-channel communication,potentially offering scalability,com-patibility,and ultra-compactness.An MDM communication system based on an NMR is theoretically designed and experimentally demonstrated to enable simultaneous and independent multi-dataset transmission,showcasing a capacity of up to 100 gigabits per second(Gbps)and a symbol error rate down to the order of 104,all achieved without any compensation technologies or correlation devices.Our work presents a paradigm that merges metasurfaces,fiber communications,and deep learning,with potential applications in intelligent metasurface-aided optical interconnection,as well as all-optical pat-tern recognition and classification.
基金supported in part by National Natural Science Foundation of China under Grant 62441115 and 62201427in part by the Ministry of Industry and Information Technology of the People’s Republic of China under Grant CBG01N23-01-04.
文摘Orbital angular momentum(OAM)can achieve multifold increase of spectrum efficiency,but the hollow divergence characteristic and Line-of-Sight(LoS)path requirement impose the crucial challenges for vortex wave communications.For air-to-ground vortex wave communications,where there exists the LoS path,this paper proposes a multi-user cooperative receive(MUCR)scheme to break through the communication distance limitation caused by the characteristic of vortex wave hollow divergence.In particular,we derive the optimal radial position corresponding to the maximum intensity,which is used to adjust the waist radius.Based on the waist radius and energy ring,the cooperative ground users having the minimum angular square difference are selected.Also,the signal compensation scheme is proposed to decompose OAM signals in air-to-ground vortex wave communications.Simulation results are presented to verify the superiority of our proposed MUCR scheme.
文摘The rapid evolution of Fifth-Generation(5G)networks and the strategic development of Sixth-Generation(6G)technologies have significantly advanced the implementation of air-ground integrated networks with seamless coverage.Unmanned Aerial Vehicles(UAVs),serving as high-mobility aerial platforms,are extensively utilized to enhance coverage in long-distance emergency communication scenarios.The resource-constrained communication environments in emergencies by classifying UAVs into swarm UAVs and relay UAVs as aerial communication nodes is inversitgated.A horizontal deployment strategy for swarm UAVs is formulated through K-means clustering algorithm optimization,while a vertical deployment scheme is established using convex optimization methods.The minimum-path trajectory planning for relay UAVs is optimized via the Particle Swarm Optimization(PSO)algorithm,enhancing communication reliability between UAV swarms and terrestrial base stations.A three-dimensional heterogeneous network architecture is realized by modeling spatial multi-hop relay links.Experimental results demonstrate that the proposed joint UAV relay optimization framework outperforms conventional algorithms in both coverage performance and relay capability during video stream transmission,achieving significant improvements in coverage enhancement and relay efficiency.This work provides technical foundations for constructing high-reliability air-ground cooperative systems in emergency communications.
基金supported by the National Key Research and Development Program of China under Grant 2018YFA0701601by the Program of Jiangsu Province under Grant NTACT-2024-Z-001.
文摘In offshore maritime communication sys-tems,base stations(BSs)are employed along the coastline to provide high-speed data service for ves-sels in coastal sea areas.To ensure the line-of-sight propagation of BS-vessel links,high transceiver an-tenna height is required,which limits the number of geographically available sites for BS deployment,and imposes a high cost for realizing effective wide-area coverage.In this paper,the joint user association and power allocation(JUAPA)problem is investigated to enhance the coverage of offshore maritime systems.By exploiting the characteristics of network topology as well as vessels’motion in offshore communica-tions,a multi-period JUAPA problem is formulated to maximize the number of ships that can be simultane-ously served by the network.This JUAPA problem is intrinsically non-convex and subject to mixed-integer constraints,which is difficult to solve either analyt-ically or numerically.Hence,we propose an iterative augmentation based framework to efficiently select the active vessels,where the JUAPA scheme is iteratively optimized by the network for increasing the number of the selected vessels.More specifically,in each itera-tion,the user association variables and power alloca-tion variables are determined by solving two separate subproblems,so that the JUAPA strategy can be up-dated in a low-complexity manner.The performance of the proposed JUAPA method is evaluated by exten-sive simulation,and numerical results indicate that it can effectively increase the number of vessels served by the network,and thus enhances the coverage of off-shore systems.
基金supported in part by National Natural Science Foundation of China under Grants 62122069,62071431,and 62201507.
文摘To address the contradiction between the explosive growth of wireless data and the limited spectrum resources,semantic communication has been emerging as a promising communication paradigm.In this paper,we thus design a speech semantic coded communication system,referred to as Deep-STS(i.e.,Deep-learning based Speech To Speech),for the lowbandwidth speech communication.Specifically,we first deeply compress the speech data through extracting the textual information from the speech based on the conformer encoder and connectionist temporal classification decoder at the transmitter side of Deep-STS system.In order to facilitate the final speech timbre recovery,we also extract the short-term timbre feature of speech signals only for the starting 2s duration by the long short-term memory network.Then,the Reed-Solomon coding and hybrid automatic repeat request protocol are applied to improve the reliability of transmitting the extracted text and timbre feature over the wireless channel.Third,we reconstruct the speech signal by the mel spectrogram prediction network and vocoder,when the extracted text is received along with the timbre feature at the receiver of Deep-STS system.Finally,we develop the demo system based on the USRP and GNU radio for the performance evaluation of Deep-STS.Numerical results show that the ac-Received:Jan.17,2024 Revised:Jun.12,2024 Editor:Niu Kai curacy of text extraction approaches 95%,and the mel cepstral distortion between the recovered speech signal and the original one in the spectrum domain is less than 10.Furthermore,the experimental results show that the proposed Deep-STS system can reduce the total delay of speech communication by 85%on average compared to the G.723 coding at the transmission rate of 5.4 kbps.More importantly,the coding rate of the proposed Deep-STS system is extremely low,only 0.2 kbps for continuous speech communication.It is worth noting that the Deep-STS with lower coding rate can support the low-zero-power speech communication,unveiling a new era in ultra-efficient coded communications.
基金supported in part by the National Natural Science Foundation of China under Grant No.62062031in part by the MIC/SCOPE#JP235006102+2 种基金in part by JST ASPIRE Grant Number JPMJAP2325in part by ROIS NII Open Collaborative Research under Grant 24S0601in part by collaborative research with Toyota Motor Corporation,Japan。
文摘Remote driving,an emergent technology enabling remote operations of vehicles,presents a significant challenge in transmitting large volumes of image data to a central server.This requirement outpaces the capacity of traditional communication methods.To tackle this,we propose a novel framework using semantic communications,through a region of interest semantic segmentation method,to reduce the communication costs by transmitting meaningful semantic information rather than bit-wise data.To solve the knowledge base inconsistencies inherent in semantic communications,we introduce a blockchain-based edge-assisted system for managing diverse and geographically varied semantic segmentation knowledge bases.This system not only ensures the security of data through the tamper-resistant nature of blockchain but also leverages edge computing for efficient management.Additionally,the implementation of blockchain sharding handles differentiated knowledge bases for various tasks,thus boosting overall blockchain efficiency.Experimental results show a great reduction in latency by sharding and an increase in model accuracy,confirming our framework's effectiveness.
基金supported by National Science and Technology Major Project of China(Project Number:2024ZD1300100)Fundamental Research Funds for the central universities(2024RC02)+1 种基金National Natural Science Foundation of China(62401077,62321001)Beijing Municipal Natural Science Foundation(L232003)。
文摘With the rapid growth of the low-altitude economy,the demand for typical low-altitude ap-plications has accelerated the advancement of inte-grated sensing and communications(ISAC)networks.This paper begins by analyzing representative ap-plication scenarios to clarify the core requirements of the low-altitude economy for modern ISAC net-works.By investigating the distinctive characteris-tics of ISAC networks in low-altitude environments,it presents a comprehensive analysis of key challenges and identifies four major issues:challenges in pre-cise target detection,interference management,in-consistent sensing and communication coverage,and the complexity of air-ground coordination and han-dover.Based on fundamental theories and principles,the paper proposes corresponding solutions,encom-passing advanced technologies for precise target de-tection and recognition,high-reliability networked de-tection,robust interference management,and seamless air-ground collaboration.These solutions aim to es-tablish a solid foundation for the future development of intelligent low-altitude networks and ensure effec-tive support for emerging applications.
