A large amount of mobile data from growing high-speed train(HST)users makes intelligent HST communications enter the era of big data.The corresponding artificial intelligence(AI)based HST channel modeling becomes a tr...A large amount of mobile data from growing high-speed train(HST)users makes intelligent HST communications enter the era of big data.The corresponding artificial intelligence(AI)based HST channel modeling becomes a trend.This paper provides AI based channel characteristic prediction and scenario classification model for millimeter wave(mmWave)HST communications.Firstly,the ray tracing method verified by measurement data is applied to reconstruct four representative HST scenarios.By setting the positions of transmitter(Tx),receiver(Rx),and other parameters,the multi-scenarios wireless channel big data is acquired.Then,based on the obtained channel database,radial basis function neural network(RBF-NN)and back propagation neural network(BP-NN)are trained for channel characteristic prediction and scenario classification.Finally,the channel characteristic prediction and scenario classification capabilities of the network are evaluated by calculating the root mean square error(RMSE).The results show that RBF-NN can generally achieve better performance than BP-NN,and is more applicable to prediction of HST scenarios.展开更多
Spatial modulation(SM) is a class of novel multiple-input multiple-output(MIMO) techniques toward future wireless communications,which activates only one transmit antenna in each time slot,so as to reduce the number o...Spatial modulation(SM) is a class of novel multiple-input multiple-output(MIMO) techniques toward future wireless communications,which activates only one transmit antenna in each time slot,so as to reduce the number of RF chains for saving the implement cost.Meanwhile,considering its application in 5G systems with multiple users,the detection of multi-user spatial modulation has drawn greater attention.In this paper,a pair of efficient detectors are proposed for multi-user spatial modulation.Specially,a threshold-aided approximate message passing(T-AMP) detector is proposed with the purpose of reducing the computational complexity of traditional structured approximate message passing(Str-AMP) detector.In addition,a novel probability sorting aided approximate message passing detector,called probability-ranking-aided AMP detector(P-AMP),is also proposed with the purpose of improving the performance.Simulation results show that the proposed T-AMP detector is able to achieve similar performance as traditional StrAMP with lower complexity,while the proposed P-AMP detector exhibits a better symbol error rate(SER) performance with similar complexity.展开更多
Unmanned aerial vehicles(UAVs)have found fast growing applications in recent years,such as for cargo delivery,precision agriculture,aerial monitoring,video streaming,traffic control,rescue and search,and communication...Unmanned aerial vehicles(UAVs)have found fast growing applications in recent years,such as for cargo delivery,precision agriculture,aerial monitoring,video streaming,traffic control,rescue and search,and communication relaying.As the number of UAVs and their related applications grow explosively in the com-展开更多
With the commercialization of the fifth generattion(5G)of wireless networks in 2019,the development of the next generation of wireless standards is currently under discussion.To cope with the target 1000x improvement ...With the commercialization of the fifth generattion(5G)of wireless networks in 2019,the development of the next generation of wireless standards is currently under discussion.To cope with the target 1000x improvement of system capacity,5G wireless standards have adopted massive MIMO as a key enabling physical layer technology to boost the spectral efficiency.展开更多
Over the past two years,reconfigurable intelligent surface(RIS),as a promising emerging technology for Beyond 5 G(B5 G) and 6 G mobile communications systems,has attracted enormous interest from both academia and indu...Over the past two years,reconfigurable intelligent surface(RIS),as a promising emerging technology for Beyond 5 G(B5 G) and 6 G mobile communications systems,has attracted enormous interest from both academia and industry worldwide.In IMT-2030(6 G) Promotion Group of China,the RIS task force was created in June 2020.展开更多
An intelligent reflecting surface(IRS)is proposed to enhance the physical layer security in the Rician fading channel wherein the angular direction of the eavesdropper(ED)is aligned with a legitimate user.A two-phase ...An intelligent reflecting surface(IRS)is proposed to enhance the physical layer security in the Rician fading channel wherein the angular direction of the eavesdropper(ED)is aligned with a legitimate user.A two-phase communication system under active attacks and passive eavesdropping is considered in this scenario.The base station avoids direct transmission to the attacked user in the first phase,whereas other users cooperate in forwarding signals to the attacked user in the second phase,with the help of IRS and energy harvesting technology.Under the occurrence of active attacks,an outage-constrained beamforming design problem is investigated under the statistical cascaded channel error model,which is solved by using the Bernstein-type inequality.An average secrecy rate maximization problem for the passive eavesdropping is formulated,which is then addressed by a low-complexity algorithm.The numerical results of this study reveal that the negative effect of the ED’s channel error is larger than that of the legitimate user.展开更多
基金supported by the National Key R&D Program of China under Grant 2021YFB1407001the National Natural Science Foundation of China (NSFC) under Grants 62001269 and 61960206006+2 种基金the State Key Laboratory of Rail Traffic Control and Safety (under Grants RCS2022K009)Beijing Jiaotong University, the Future Plan Program for Young Scholars of Shandong Universitythe EU H2020 RISE TESTBED2 project under Grant 872172
文摘A large amount of mobile data from growing high-speed train(HST)users makes intelligent HST communications enter the era of big data.The corresponding artificial intelligence(AI)based HST channel modeling becomes a trend.This paper provides AI based channel characteristic prediction and scenario classification model for millimeter wave(mmWave)HST communications.Firstly,the ray tracing method verified by measurement data is applied to reconstruct four representative HST scenarios.By setting the positions of transmitter(Tx),receiver(Rx),and other parameters,the multi-scenarios wireless channel big data is acquired.Then,based on the obtained channel database,radial basis function neural network(RBF-NN)and back propagation neural network(BP-NN)are trained for channel characteristic prediction and scenario classification.Finally,the channel characteristic prediction and scenario classification capabilities of the network are evaluated by calculating the root mean square error(RMSE).The results show that RBF-NN can generally achieve better performance than BP-NN,and is more applicable to prediction of HST scenarios.
基金The financial support is gratefully acknowledged by the National Science Foundation of China under Grant numbers 61471090the Open Research Fund of National Mobile Communications Research Laboratory,Southeast University(No.2015D09)+1 种基金the Foundation Project of Science and Technology on Electronic Information Control Laboratory under Grant JS17041403811(201606071370-004001)the Foundation Project of National Key Lab.of Sci.and Tech.on Comm.under Grant 6142102010702
文摘Spatial modulation(SM) is a class of novel multiple-input multiple-output(MIMO) techniques toward future wireless communications,which activates only one transmit antenna in each time slot,so as to reduce the number of RF chains for saving the implement cost.Meanwhile,considering its application in 5G systems with multiple users,the detection of multi-user spatial modulation has drawn greater attention.In this paper,a pair of efficient detectors are proposed for multi-user spatial modulation.Specially,a threshold-aided approximate message passing(T-AMP) detector is proposed with the purpose of reducing the computational complexity of traditional structured approximate message passing(Str-AMP) detector.In addition,a novel probability sorting aided approximate message passing detector,called probability-ranking-aided AMP detector(P-AMP),is also proposed with the purpose of improving the performance.Simulation results show that the proposed T-AMP detector is able to achieve similar performance as traditional StrAMP with lower complexity,while the proposed P-AMP detector exhibits a better symbol error rate(SER) performance with similar complexity.
文摘Unmanned aerial vehicles(UAVs)have found fast growing applications in recent years,such as for cargo delivery,precision agriculture,aerial monitoring,video streaming,traffic control,rescue and search,and communication relaying.As the number of UAVs and their related applications grow explosively in the com-
文摘With the commercialization of the fifth generattion(5G)of wireless networks in 2019,the development of the next generation of wireless standards is currently under discussion.To cope with the target 1000x improvement of system capacity,5G wireless standards have adopted massive MIMO as a key enabling physical layer technology to boost the spectral efficiency.
文摘Over the past two years,reconfigurable intelligent surface(RIS),as a promising emerging technology for Beyond 5 G(B5 G) and 6 G mobile communications systems,has attracted enormous interest from both academia and industry worldwide.In IMT-2030(6 G) Promotion Group of China,the RIS task force was created in June 2020.
文摘An intelligent reflecting surface(IRS)is proposed to enhance the physical layer security in the Rician fading channel wherein the angular direction of the eavesdropper(ED)is aligned with a legitimate user.A two-phase communication system under active attacks and passive eavesdropping is considered in this scenario.The base station avoids direct transmission to the attacked user in the first phase,whereas other users cooperate in forwarding signals to the attacked user in the second phase,with the help of IRS and energy harvesting technology.Under the occurrence of active attacks,an outage-constrained beamforming design problem is investigated under the statistical cascaded channel error model,which is solved by using the Bernstein-type inequality.An average secrecy rate maximization problem for the passive eavesdropping is formulated,which is then addressed by a low-complexity algorithm.The numerical results of this study reveal that the negative effect of the ED’s channel error is larger than that of the legitimate user.
