In tubers of two potato cultivars and in one apple cultivar, water clusters, consisting of 11 ± 1, 100, 178, 280, 402, 545, 715, 903, 119, 1351, 1606 and 1889 molecules, were directly (in-vivo) analyzed by gravit...In tubers of two potato cultivars and in one apple cultivar, water clusters, consisting of 11 ± 1, 100, 178, 280, 402, 545, 715, 903, 119, 1351, 1606 and 1889 molecules, were directly (in-vivo) analyzed by gravitation spectroscopy. The clusters’ interactions with their surroundings during plant growth in summer 2006 in Germany were described where a model represents the states of water clusters in bio matrices. Furthermore, a comparison with clusters in irrigation water (river, rain) is given. To achieve a high and good quality yield it is necessary to choose the right irrigation water that has to correspond with the water cluster super structure in plants. The formation energy for the (H2O)280 cluster during plant growth is between 0.4 and 1.3 kJ/mol. Water clusters were found to communicate with surroundings by resonance field oscillations. The main cluster parameters which were investigated are intensities of oscillations, average molecular masses, rate of collapsed clusters, and total number of clusters in ensemble during potato (apple) growth. A correlation between the change of water cluster ensembles in plants with molecular masses of all clusters in isolated starch (in-vitro) during plant growth process is discussed. In particular for potato tubers’ growth, there was observed a correlation between water cluster development and average molecular masses of amylopectin super coils. The com-munication of plants with each other and with surroundings proceeds by resonance field of oscillating water clusters. Planet gravitation was found to influence the water cluster structure in plants.展开更多
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
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
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
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
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
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
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
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
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
1.Introduction Mobile communications have catalyzed a new era of informa-tion technology revolution,significantly broadening and deepen-ing human-to-human,human-to-machine,and machine-to-machine connections.With their...1.Introduction Mobile communications have catalyzed a new era of informa-tion technology revolution,significantly broadening and deepen-ing human-to-human,human-to-machine,and machine-to-machine connections.With their incredible speed of development and wide-reaching impact,mobile communications serve as the cornerstone of the Internet of Everything,profoundly reshaping human cognitive abilities and ways of thinking.Furthermore,mobile communications are altering the patterns of production and life,driving leaps in productivity quality,and strongly promot-ing innovation within human civilization.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
With the widespread application of com-munication technology in the non-terrestrial network(NTN),the issue of the insecure communication due to the inherent openness of the NTN is increasingly being recognized.Consequ...With the widespread application of com-munication technology in the non-terrestrial network(NTN),the issue of the insecure communication due to the inherent openness of the NTN is increasingly being recognized.Consequently,safeguarding com-munication information in the NTN has emerged as a critical challenge.To address this issue,we pro-pose a beamforming and horizontal trajectory joint op-timization method for unmanned aerial vehicle(UAV)covert communications in the NTN.First,we formu-late an optimization problem that considers constraints such as the transmitting power and the distance.More-over,we employ the integrated communication and jamming(ICAJ)signal as Alice’s transmitting signal,further protecting the content of communication in-formation.Next,we construct two subproblems,and we propose an alternate optimization(AO)algorithm based on quadratic transform and penalty term method to solve the proposed two subproblems.Simulation re-sults demonstrate that the proposed method is effective and has better performance than benchmarks.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
Dear Editor,This letter is concerned with the problem of time-varying formation tracking for heterogeneous multi-agent systems(MASs) under directed switching networks. For this purpose, our first step is to present so...Dear Editor,This letter is concerned with the problem of time-varying formation tracking for heterogeneous multi-agent systems(MASs) under directed switching networks. For this purpose, our first step is to present some sufficient conditions for the exponential stability of a particular category of switched systems.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
Existing orthogonal space-time block coding(OSTBC)schemes for backscatter communication systems cannot achieve a full transmission code rate when the tag is equipped with more than two antennas.In this paper,we propos...Existing orthogonal space-time block coding(OSTBC)schemes for backscatter communication systems cannot achieve a full transmission code rate when the tag is equipped with more than two antennas.In this paper,we propose a quasi-orthogonal spacetime block code(QOSTBC)that can achieve a full transmission code rate for backscatter communication systems with a four-antenna tag and then extend the scheme to support tags with 2i antennas.Specifically,we first present the system model for the backscatter system.Next,we propose the QOSTBC scheme to encode the tag signals.Then,we provide the corresponding maximum likelihood detection algorithms to recover the tag signals.Finally,simulation results are provided to demonstrate that our proposed QOSTBC scheme and the detection algorithm can achieve a better transmission code rate or symbol error rate performance for backscatter communication systems compared with benchmark schemes.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
基金The financial support by the,Aist Handels-und Consulting“GmbH(FNS-project)is gratefully acknowledged.
文摘In tubers of two potato cultivars and in one apple cultivar, water clusters, consisting of 11 ± 1, 100, 178, 280, 402, 545, 715, 903, 119, 1351, 1606 and 1889 molecules, were directly (in-vivo) analyzed by gravitation spectroscopy. The clusters’ interactions with their surroundings during plant growth in summer 2006 in Germany were described where a model represents the states of water clusters in bio matrices. Furthermore, a comparison with clusters in irrigation water (river, rain) is given. To achieve a high and good quality yield it is necessary to choose the right irrigation water that has to correspond with the water cluster super structure in plants. The formation energy for the (H2O)280 cluster during plant growth is between 0.4 and 1.3 kJ/mol. Water clusters were found to communicate with surroundings by resonance field oscillations. The main cluster parameters which were investigated are intensities of oscillations, average molecular masses, rate of collapsed clusters, and total number of clusters in ensemble during potato (apple) growth. A correlation between the change of water cluster ensembles in plants with molecular masses of all clusters in isolated starch (in-vitro) during plant growth process is discussed. In particular for potato tubers’ growth, there was observed a correlation between water cluster development and average molecular masses of amylopectin super coils. The com-munication of plants with each other and with surroundings proceeds by resonance field of oscillating water clusters. Planet gravitation was found to influence the water cluster structure in plants.
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.
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.
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.
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.
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.
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.
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.
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.
基金supported by the National Key Research and Develop-ment Program of China(2019YFB1803400).
文摘1.Introduction Mobile communications have catalyzed a new era of informa-tion technology revolution,significantly broadening and deepen-ing human-to-human,human-to-machine,and machine-to-machine connections.With their incredible speed of development and wide-reaching impact,mobile communications serve as the cornerstone of the Internet of Everything,profoundly reshaping human cognitive abilities and ways of thinking.Furthermore,mobile communications are altering the patterns of production and life,driving leaps in productivity quality,and strongly promot-ing innovation within human civilization.
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 Natural Science Foundation of China under Grant U2441250 and 62231027in part by Natural Science Basic Research Programof Shaanxi under Grant 2024JC-JCQN-63+2 种基金in part by InnovationCapability Support Program of Shaanxi under Grant2024RS-CXTD-01in part by New Technology Research University Cooperation Project under Grant SKX242010031in part by the FundamentalResearch Funds for the Central Universities and theInnovation Fund of Xidian University under GrantYJSJ25007.
文摘With the widespread application of com-munication technology in the non-terrestrial network(NTN),the issue of the insecure communication due to the inherent openness of the NTN is increasingly being recognized.Consequently,safeguarding com-munication information in the NTN has emerged as a critical challenge.To address this issue,we pro-pose a beamforming and horizontal trajectory joint op-timization method for unmanned aerial vehicle(UAV)covert communications in the NTN.First,we formu-late an optimization problem that considers constraints such as the transmitting power and the distance.More-over,we employ the integrated communication and jamming(ICAJ)signal as Alice’s transmitting signal,further protecting the content of communication in-formation.Next,we construct two subproblems,and we propose an alternate optimization(AO)algorithm based on quadratic transform and penalty term method to solve the proposed two subproblems.Simulation re-sults demonstrate that the proposed method is effective and has better performance than benchmarks.
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.
基金supported in part by the National Natural Science Foundation of China(62273255,62350003,62088101)the Shanghai Science and Technology Cooperation Project(22510712000,21550760900)+1 种基金the Shanghai Municipal Science and Technology Major Project(2021SHZDZX0100)the Fundamental Research Funds for the Central Universities
文摘Dear Editor,This letter is concerned with the problem of time-varying formation tracking for heterogeneous multi-agent systems(MASs) under directed switching networks. For this purpose, our first step is to present some sufficient conditions for the exponential stability of a particular category of switched systems.
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.
基金supported by Beijing Municipal Natural Science Foundation(L222002)the Natural Science Foundation of China(U22B2004).
文摘Existing orthogonal space-time block coding(OSTBC)schemes for backscatter communication systems cannot achieve a full transmission code rate when the tag is equipped with more than two antennas.In this paper,we propose a quasi-orthogonal spacetime block code(QOSTBC)that can achieve a full transmission code rate for backscatter communication systems with a four-antenna tag and then extend the scheme to support tags with 2i antennas.Specifically,we first present the system model for the backscatter system.Next,we propose the QOSTBC scheme to encode the tag signals.Then,we provide the corresponding maximum likelihood detection algorithms to recover the tag signals.Finally,simulation results are provided to demonstrate that our proposed QOSTBC scheme and the detection algorithm can achieve a better transmission code rate or symbol error rate performance for backscatter communication systems compared with benchmark schemes.
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.
