多天线技术通过在收发端部署天线阵列,从而提供额外的空间自由度(degrees of freedom,DoFs),大幅提升了无线通信的可靠性与有效性。与此同时,多天线技术应用于雷达感知领域,实现了空间角度分辨能力并提升了感知自由度,大幅增强了无线感...多天线技术通过在收发端部署天线阵列,从而提供额外的空间自由度(degrees of freedom,DoFs),大幅提升了无线通信的可靠性与有效性。与此同时,多天线技术应用于雷达感知领域,实现了空间角度分辨能力并提升了感知自由度,大幅增强了无线感知性能。然而,无线通信与雷达感知领域在过去数十年里独立发展。因此,尽管多天线技术在这两个领域分别取得了巨大的进步,但并没有通过发挥它们的协同作用来实现深度融合。随着感知与通信的融合被确定为第六代(the sixth-generation,6G)移动通信网络的典型应用场景之一,多天线技术的发展面临新的机遇以填补上述空白。为此,本文围绕未来天线阵列规模持续扩张、阵列架构更加多样、阵列形态更为灵活等发展趋势,对面向6G通信感知一体化的多天线技术进行综述。首先介绍未来多天线的不同架构类型,包括以传统紧凑式阵列和新兴稀疏阵列为代表的集中式阵列架构、以无蜂窝大规模MIMO(multiple-input multiple-output)为代表的分布式天线架构,以及三维连续空间阵元位置与朝向灵活可调的可移动天线/流体天线。然后,本文将介绍基于上述天线架构的远场/近场信道建模,并进行通信与感知性能分析。最后总结不同天线架构的特点,并展望解决因天线阵列规模的持续扩展及阵列形态的灵活多变引起的信道状态信息获取困难的新思路。展开更多
In the areas without terrestrial communication infrastructures,unmanned aerial vehicles(UAVs)can be utilized to serve field robots for mission-critical tasks.For this purpose,UAVs can be equipped with sensing,communic...In the areas without terrestrial communication infrastructures,unmanned aerial vehicles(UAVs)can be utilized to serve field robots for mission-critical tasks.For this purpose,UAVs can be equipped with sensing,communication,and computing modules to support various requirements of robots.In the task process,different modules assist the robots to perform tasks in a closed-loop way,which is referred to as a sensing-communication-computing-control(SC3)loop.In this work,we investigate a UAV-aided system containing multiple SC^(3)loops,which leverages non-orthogonal multiple access(NOMA)for efficient resource sharing.We describe and compare three different modelling levels for the SC^(3)loop.Based on the entropy SC^(3)loop model,a sum linear quadratic regulator(LQR)control cost minimization problem is formulated by optimizing the communication power.Further for the assure-to-be-stable case,we show that the original problem can be approximated by a modified user fairness problem,and accordingly gain more insights into the optimal solutions.Simulation results demonstrate the performance gain of using NOMA in such task-oriented systems,as well as the superiority of our proposed closed-loop-oriented design.展开更多
This paper explores a double quantum images representation(DNEQR)model that allows for simultaneous storage of two digital images in a quantum superposition state.Additionally,a new type of two-dimensional hyperchaoti...This paper explores a double quantum images representation(DNEQR)model that allows for simultaneous storage of two digital images in a quantum superposition state.Additionally,a new type of two-dimensional hyperchaotic system based on sine and logistic maps is investigated,offering a wider parameter space and better chaotic behavior compared to the sine and logistic maps.Based on the DNEQR model and the hyperchaotic system,a double quantum images encryption algorithm is proposed.Firstly,two classical plaintext images are transformed into quantum states using the DNEQR model.Then,the proposed hyperchaotic system is employed to iteratively generate pseudo-random sequences.These chaotic sequences are utilized to perform pixel value and position operations on the quantum image,resulting in changes to both pixel values and positions.Finally,the ciphertext image can be obtained by qubit-level diffusion using two XOR operations between the position-permutated image and the pseudo-random sequences.The corresponding quantum circuits are also given.Experimental results demonstrate that the proposed scheme ensures the security of the images during transmission,improves the encryption efficiency,and enhances anti-interference and anti-attack capabilities.展开更多
In addition to conventional antenna-based array,the reconfigurable intelligent surface(RIS)holds promise as an alternative technology for manufacturing massive multi-input multi-output(MIMO)array for beyond 5G communi...In addition to conventional antenna-based array,the reconfigurable intelligent surface(RIS)holds promise as an alternative technology for manufacturing massive multi-input multi-output(MIMO)array for beyond 5G communications.This paper designs a fast algorithm to optimize the RIS-based MIMO precoder for maximizing the spectral efficiency,which includes the digital precoder and the RIS reflection phases.We evaluate the optimality of the algorithm by deriving an RIS channel capacity upper bound utilizing majorization theory.Our scheme can work for an RIS in both frequency flat and frequency selective channels,with either continuously or discretely tunable phases.The simulation results show that the proposed algorithm can achieve the capacity upper bound in some scenarios,which empirically proves its optimality.It is also shown that our algorithm is one-to-two orders of magnitude faster than the state-of-the-art methods in the literature.展开更多
Carbonaceous materials in seismic fault zones may considerably influence seismic fault slip;however,the formation mechanism of carbonaceous materials remains unclear.In this study,we proposed a novel hypothesis for th...Carbonaceous materials in seismic fault zones may considerably influence seismic fault slip;however,the formation mechanism of carbonaceous materials remains unclear.In this study,we proposed a novel hypothesis for the formation of carbonaceous materials in fault gouge.Thus,we conducted a CO_(2) hydrogenation experiment in a high-temperature reactor at a co-seismic temperature,with fault gouge formed during the Wenchuan earthquake as the catalyst.Our experimental results demonstrate that carbonaceous materials in fault zones are formed on the fault gouge during the chemical reaction process,suggesting that the carbonaceous materials are possibly generated from the catalytic hydrogenation of CO_(2),followed by thermal cracking of its products.The results of this study provide a theoretical basis for understanding fault behavior and earthquake physics.展开更多
IEEE International Conference on Communication Technology(ICCT)was jointly initiated and organized by IEEE Beijing Section and IEEE Com Soc in 1986.It is one of the highest-level academic events in the field of commun...IEEE International Conference on Communication Technology(ICCT)was jointly initiated and organized by IEEE Beijing Section and IEEE Com Soc in 1986.It is one of the highest-level academic events in the field of communication technology in China.It is also an international gathering for research for information and communication technology.展开更多
Extremely large-scale hybrid reconfigurable intelligence surface(XL-HRIS),an improved version of the RIS,can receive the incident signal and enhance communication performance.However,as the RIS size increases,the phas...Extremely large-scale hybrid reconfigurable intelligence surface(XL-HRIS),an improved version of the RIS,can receive the incident signal and enhance communication performance.However,as the RIS size increases,the phase variations of the received signal across the whole array are nonnegligible in the near-field region,and the channel model mismatch,which will decrease the estimation accuracy,must be considered.In this paper,the lower bound(LB)of the estimated parameter is studied and the impacts of the distance and signal-tonoise ratio(SNR)on LB are then evaluated.Moreover,the impacts of the array scale on LB and spectral efficiency(SE)are also studied.Simulation results verify that even in extremely large-scale array systems with infinite SNR,channel model mismatch can still limit estimation accuracy.However,this impact decreases with increasing distance.展开更多
文摘多天线技术通过在收发端部署天线阵列,从而提供额外的空间自由度(degrees of freedom,DoFs),大幅提升了无线通信的可靠性与有效性。与此同时,多天线技术应用于雷达感知领域,实现了空间角度分辨能力并提升了感知自由度,大幅增强了无线感知性能。然而,无线通信与雷达感知领域在过去数十年里独立发展。因此,尽管多天线技术在这两个领域分别取得了巨大的进步,但并没有通过发挥它们的协同作用来实现深度融合。随着感知与通信的融合被确定为第六代(the sixth-generation,6G)移动通信网络的典型应用场景之一,多天线技术的发展面临新的机遇以填补上述空白。为此,本文围绕未来天线阵列规模持续扩张、阵列架构更加多样、阵列形态更为灵活等发展趋势,对面向6G通信感知一体化的多天线技术进行综述。首先介绍未来多天线的不同架构类型,包括以传统紧凑式阵列和新兴稀疏阵列为代表的集中式阵列架构、以无蜂窝大规模MIMO(multiple-input multiple-output)为代表的分布式天线架构,以及三维连续空间阵元位置与朝向灵活可调的可移动天线/流体天线。然后,本文将介绍基于上述天线架构的远场/近场信道建模,并进行通信与感知性能分析。最后总结不同天线架构的特点,并展望解决因天线阵列规模的持续扩展及阵列形态的灵活多变引起的信道状态信息获取困难的新思路。
基金supported in part by the National Key Research and Development Program of China under Grant 2020YFA0711301in part by the National Natural Science Foundation of China under Grant 62341110, Grant U22A2002, and Grant 62025110in part by the Suzhou Science and Technology Project
文摘In the areas without terrestrial communication infrastructures,unmanned aerial vehicles(UAVs)can be utilized to serve field robots for mission-critical tasks.For this purpose,UAVs can be equipped with sensing,communication,and computing modules to support various requirements of robots.In the task process,different modules assist the robots to perform tasks in a closed-loop way,which is referred to as a sensing-communication-computing-control(SC3)loop.In this work,we investigate a UAV-aided system containing multiple SC^(3)loops,which leverages non-orthogonal multiple access(NOMA)for efficient resource sharing.We describe and compare three different modelling levels for the SC^(3)loop.Based on the entropy SC^(3)loop model,a sum linear quadratic regulator(LQR)control cost minimization problem is formulated by optimizing the communication power.Further for the assure-to-be-stable case,we show that the original problem can be approximated by a modified user fairness problem,and accordingly gain more insights into the optimal solutions.Simulation results demonstrate the performance gain of using NOMA in such task-oriented systems,as well as the superiority of our proposed closed-loop-oriented design.
基金Project supported by the Open Fund of Anhui Key Laboratory of Mine Intelligent Equipment and Technology (Grant No.ZKSYS202204)the Talent Introduction Fund of Anhui University of Science and Technology (Grant No.2021yjrc34)the Scientific Research Fund of Anhui Provincial Education Department (Grant No.KJ2020A0301)。
文摘This paper explores a double quantum images representation(DNEQR)model that allows for simultaneous storage of two digital images in a quantum superposition state.Additionally,a new type of two-dimensional hyperchaotic system based on sine and logistic maps is investigated,offering a wider parameter space and better chaotic behavior compared to the sine and logistic maps.Based on the DNEQR model and the hyperchaotic system,a double quantum images encryption algorithm is proposed.Firstly,two classical plaintext images are transformed into quantum states using the DNEQR model.Then,the proposed hyperchaotic system is employed to iteratively generate pseudo-random sequences.These chaotic sequences are utilized to perform pixel value and position operations on the quantum image,resulting in changes to both pixel values and positions.Finally,the ciphertext image can be obtained by qubit-level diffusion using two XOR operations between the position-permutated image and the pseudo-random sequences.The corresponding quantum circuits are also given.Experimental results demonstrate that the proposed scheme ensures the security of the images during transmission,improves the encryption efficiency,and enhances anti-interference and anti-attack capabilities.
基金supported by National Natural Science Foundation of China Grant No.61771005。
文摘In addition to conventional antenna-based array,the reconfigurable intelligent surface(RIS)holds promise as an alternative technology for manufacturing massive multi-input multi-output(MIMO)array for beyond 5G communications.This paper designs a fast algorithm to optimize the RIS-based MIMO precoder for maximizing the spectral efficiency,which includes the digital precoder and the RIS reflection phases.We evaluate the optimality of the algorithm by deriving an RIS channel capacity upper bound utilizing majorization theory.Our scheme can work for an RIS in both frequency flat and frequency selective channels,with either continuously or discretely tunable phases.The simulation results show that the proposed algorithm can achieve the capacity upper bound in some scenarios,which empirically proves its optimality.It is also shown that our algorithm is one-to-two orders of magnitude faster than the state-of-the-art methods in the literature.
文摘Carbonaceous materials in seismic fault zones may considerably influence seismic fault slip;however,the formation mechanism of carbonaceous materials remains unclear.In this study,we proposed a novel hypothesis for the formation of carbonaceous materials in fault gouge.Thus,we conducted a CO_(2) hydrogenation experiment in a high-temperature reactor at a co-seismic temperature,with fault gouge formed during the Wenchuan earthquake as the catalyst.Our experimental results demonstrate that carbonaceous materials in fault zones are formed on the fault gouge during the chemical reaction process,suggesting that the carbonaceous materials are possibly generated from the catalytic hydrogenation of CO_(2),followed by thermal cracking of its products.The results of this study provide a theoretical basis for understanding fault behavior and earthquake physics.
文摘IEEE International Conference on Communication Technology(ICCT)was jointly initiated and organized by IEEE Beijing Section and IEEE Com Soc in 1986.It is one of the highest-level academic events in the field of communication technology in China.It is also an international gathering for research for information and communication technology.
基金supported in part by the National Natural Science Founda⁃tion of China(NSFC)under Grant Nos.62301148,62341107,and 62261160576by the Natural Science Foundation of Jiangsu Prov⁃ince under Grant No.BK20230824in part by the Key Technologies R&D Program of Jiangsu(Prospective and Key Technologies for Indus⁃try)under Grant Nos.BE2023022 and BE2023022-1.
文摘Extremely large-scale hybrid reconfigurable intelligence surface(XL-HRIS),an improved version of the RIS,can receive the incident signal and enhance communication performance.However,as the RIS size increases,the phase variations of the received signal across the whole array are nonnegligible in the near-field region,and the channel model mismatch,which will decrease the estimation accuracy,must be considered.In this paper,the lower bound(LB)of the estimated parameter is studied and the impacts of the distance and signal-tonoise ratio(SNR)on LB are then evaluated.Moreover,the impacts of the array scale on LB and spectral efficiency(SE)are also studied.Simulation results verify that even in extremely large-scale array systems with infinite SNR,channel model mismatch can still limit estimation accuracy.However,this impact decreases with increasing distance.
