The maritime communication networks(MCNs)for industry require reliable,efficient,and wide coverage to deploy emerging intelligent marine applications.To this end,unmanned aerial vehicles(UAVs)can be integrated into MC...The maritime communication networks(MCNs)for industry require reliable,efficient,and wide coverage to deploy emerging intelligent marine applications.To this end,unmanned aerial vehicles(UAVs)can be integrated into MCNs to extend flexibility and mobility.However,harsh maritime environments and open line-of-sight(LoS)links increase the UAV onboard energy consumption and worsen communication security.In this work,we aim to propose a collaborative beamforming-based physical layer secure and energy-efficient communication method for UAV-assisted MCNs,in which the energy limitations of UAVs and the interference from both known and unknown eavesdroppers as well as the possible collusion among eavesdroppers are considered.Specifically,we formulate a multi-objective optimization problem(MOP)to improve the system confidentiality rate,reduce the level ratio of the UAV virtual antenna array,and decrease the energy consumption of the UAVs by jointly optimizing the UAV positions and synthesizing the UAV virtual antenna array.This MOP is non-convex and NP-hard,and thus we propose an enhanced non-dominated sorted whale optimization algorithm(ENSWOA)to solve the problem.In ENSWOA,the introduced chaotic solution initialization,adaptive weighting,and optimal position updating methods can increase the searching capability of the algorithm.Simulation results show that the proposed ENSWOA outperforms the baseline algorithms,and can effectively enhance the security and energy efficiency of the considered system.展开更多
The initial cell search plays an important role during the process of downlink synchronization establishment between the User Equipment(UE) and the base station. In particular, the uncertainty of the synchronization s...The initial cell search plays an important role during the process of downlink synchronization establishment between the User Equipment(UE) and the base station. In particular, the uncertainty of the synchronization signals on the frequency domain and the flexibility of frame structure configuration have brought great challenges to the initial cell search for the fifth-generation(5G) new radio(NR). To solve this problem, firstly, we analyze the physical layer frame structure of 5G NR systems. Then, by focusing on the knowledge of synchronization signals, the 5G NR cell search process is designed, and the primary synchronization signal(PSS) timing synchronization algorithm is proposed, including a 5G-based coarse synchronization algorithm and conjugate symmetry-based fine synchronization algorithm. Finally, the performance of the proposed cell search algorithm in 5G NR systems is verified through the combination of Digital Signal Processing(DSP) and personal computer(PC). And the MATLAB simulation proves that the proposed algorithm has better performance than the conventional cross-correlation algorithm when a certain frequency offset exists.展开更多
Ultra-densification of radio access network(RAN)is a key to efficiently support the exponentially growing mobile data traffic in 5 G era.Furthermore,extremely high frequency band like mm Wave band was utilized to solv...Ultra-densification of radio access network(RAN)is a key to efficiently support the exponentially growing mobile data traffic in 5 G era.Furthermore,extremely high frequency band like mm Wave band was utilized to solve the bandwidth shortage problem.However,untra-dense reusing the same radio resource produced severe interference.And the mm Wave link was very harsh due to frequent blockage by obstacles.Therefore a new RAN architecture needed to be introduced to realize ultra-reliable communications in such a severe radio propagation environment.An architecture of distributed MIMO based RAN was presented.Then,enhanced interference coordination(e IC)was described.Finally,the effectiveness of distributed MIMO based RAN with e IC by computer simulation was showed.展开更多
Compared to OFDM systems with cyclic prefi x, fi lterbank multicarrier with offset quadrature amplitude modulation(FBMC/OQAM) system is considered as an alternative technology for next generation wireless communicatio...Compared to OFDM systems with cyclic prefi x, fi lterbank multicarrier with offset quadrature amplitude modulation(FBMC/OQAM) system is considered as an alternative technology for next generation wireless communication systems. However, FBMC systems suffer from intrinsic imaginary interference caused by the real-fi eld orthogonality destruction when passing through complex-valued fading channels. By analyzing the transmultiplexer's response of FBMC/OQAM systems, in this paper, a simple conjugated transmission scheme is proposed for FBMC/OQAM systems. Following the specific conjugation design, the intrinsic imaginary interference including the intrinsic inter-symbol and the inter-carrier interference can be eliminated at the receiver side through linear signal processing operation. Meanwhile, the proposed conjugated transmission scheme is able to obtain extra linear combination diversity gains for improving the systematic performance of FBMC/OQAM. Simulation results show that the proposed scheme is more efficient than conventional methods, especially in practical application scenarios with large Doppler spread caused by high-speed movement.展开更多
On the basis of the first paper’s theoretical derivations and concrete instance calculations of the energies of the d orbitals for a low spin ( S =1/2) nd 5(t 2 5, 2T 2)(n =3, 4, 5) system, the ma...On the basis of the first paper’s theoretical derivations and concrete instance calculations of the energies of the d orbitals for a low spin ( S =1/2) nd 5(t 2 5, 2T 2)(n =3, 4, 5) system, the major results reported in this paper contain the following two respects: explicit relationships between the coefficients of the real and complex Kramers doublets have been derived by using two types of the expressions of the principal components of the g tensors in real and complex orbital representations obtained in the first paper; the use of these relationships of the real and complex orbital coefficients has carried out a series of mathematical demonstrations on the agreement of the real and complex orbital methods .展开更多
This paper investigates the distribution of contact resistance of the aluminum alloy in the squeeze stage. A new method of measuring path＇ s resistance is proposed firstly. Contact resistances are calculated accurate...This paper investigates the distribution of contact resistance of the aluminum alloy in the squeeze stage. A new method of measuring path＇ s resistance is proposed firstly. Contact resistances are calculated accurately by the systems of 5 linear equations and solutions show that three contact resistances are different. The probability density functions of contact resistance in workpiece/workpiece（ W/W） and upper electrode/workpiece（ E/W） show that the curve shape has steeper peak and heavier tail than that of the normal distribution. Non-parameter hypothesis test is performed and the result shows that R2 , R4 reject the normal distribution using chi-square and kolmogoroo statistic D method. Therefore, the Asymmetric Laplace distribution is fitted to empirical distributions and is applied to quantify the influence of random contact resistance. The result illustrates that AL distribution is very close to contact resistance of W/W and upper E/W and normal distribution has some deviation. The paper is helpful to research the initial nugget conditions, weldability and the transient multi-coupling field.展开更多
For a 5G wireless communication system,a convolutional deep neural network(CNN)is employed to synthesize a robust channel state estimator(CSE).The proposed CSE extracts channel information from transmit-and-receive pa...For a 5G wireless communication system,a convolutional deep neural network(CNN)is employed to synthesize a robust channel state estimator(CSE).The proposed CSE extracts channel information from transmit-and-receive pairs through offline training to estimate the channel state information.Also,it utilizes pilots to offer more helpful information about the communication channel.The proposedCNN-CSE performance is compared with previously published results for Bidirectional/long short-term memory(BiLSTM/LSTM)NNs-based CSEs.The CNN-CSE achieves outstanding performance using sufficient pilots only and loses its functionality at limited pilots compared with BiLSTM and LSTM-based estimators.Using three different loss function-based classification layers and the Adam optimization algorithm,a comparative study was conducted to assess the performance of the presented DNNs-based CSEs.The BiLSTM-CSE outperforms LSTM,CNN,conventional least squares(LS),and minimum mean square error(MMSE)CSEs.In addition,the computational and learning time complexities for DNN-CSEs are provided.These estimators are promising for 5G and future communication systems because they can analyze large amounts of data,discover statistical dependencies,learn correlations between features,and generalize the gotten knowledge.展开更多
In the era of 5G,seamless mobility handovers are critical in densely populated regions like Malaysia to mitigate disruptions and inefficiencies.5G networks offer unprecedented data speeds and reliability,essential for...In the era of 5G,seamless mobility handovers are critical in densely populated regions like Malaysia to mitigate disruptions and inefficiencies.5G networks offer unprecedented data speeds and reliability,essential for advancing mobile communication and Internet of Things applications.However,ensuring continuous connectivity and service during mobility remains challenging,especially in urban settings.Digital twin technology pre-sents a promising solution to enhance 5G handover mechanisms.A digital twin network(DTN)mirroring Malaysia's 5G infrastructure is proposed,utilising real-time data and user behaviour insights to optimise energy consumption during handovers.The focus is on energy-efficient protocols and algorithms,reviewed through a systematic literature review.The DTN aims to enhance mobility handover efficiency through predictive handovers and adaptive resource allocation,bolstered by sustainable practices such as edge computing.The potential of DTNs to optimise 5G handover processes is explored,starting with the foundational concepts of 5G mobility and digital twins,highlighting the need for improved strategies in high-mobility scenarios.Methodologies leveraging digital twins to predict network conditions,simulate handover scenarios,and proactively manage decisions are examined,reducing latency and packet loss.Case studies demonstrate how digital twins adapt dynamically to network changes and user mobility,thereby improving quality of service and user experience.Malaysia's specific 5G mobility challenges are addressed with a tailored DTN emphasising energy efficiency,evaluated through practical applications.Evaluation criteria assess effectiveness with in-depth analysis of methods,performance metrics,limitations,and recommendations for future research.Challenges and future directions including scalability,security,and real-time data processing,are discussed,aiming to integrate digital twin technology with 5G networks for enhanced connectivity.This abstract provides a roadmap for leveraging digital twins to optimise 5G network performance sustainably,guiding future research and implementation strategies.展开更多
Electron-boson interaction is fundamental to a thorough understanding of various exotic properties emerging in many-body physics. In photoemission spectroscopy, photoelectron emission due to photon absorption would tr...Electron-boson interaction is fundamental to a thorough understanding of various exotic properties emerging in many-body physics. In photoemission spectroscopy, photoelectron emission due to photon absorption would trigger diverse collective excitations in solids, including the emergence of phonons,magnons, electron-hole pairs, and plasmons, which naturally provides a reliable pathway to study electron-boson couplings. While fingerprints of electron–phonon/-magnon interactions in this state-ofthe-art technique have been well investigated, much less is known about electron-plasmon coupling,and direct observation of the band renormalization solely due to electron-plasmon interactions is extremely challenging. Here by utilizing integrated oxide molecular-beam epitaxy and angle-resolved photoemission spectroscopy, we discover the long sought-after pure electron-plasmon couplinginduced low-lying plasmonic-polaron replica bands in epitaxial semimetallic SrIrO_(3) films, in which the characteristic low carrier concentration and narrow bandwidth combine to provide a unique platform where the electron-plasmon interaction can be investigated kinematically in photoemission spectroscopy. This finding enriches the forms of electron band normalization on collective modes in solids and demonstrates that, to obtain a complete understanding of the quasiparticle dynamics in 5 d electron systems, the electron-plasmon interaction should be considered on equal footing with the acknowledged electron–electron interaction and spin–orbit coupling.展开更多
The fifth generation mobile communication（5G） systems can provide Gbit/s data rates from massive multiple-input multiple-output（MIMO） combined with the emerging use of millimeter wavelengths in small heterogeneous...The fifth generation mobile communication（5G） systems can provide Gbit/s data rates from massive multiple-input multiple-output（MIMO） combined with the emerging use of millimeter wavelengths in small heterogeneous cells. This paper develops an energy-efficiency based multi-user hybrid beamforming for downlink millimeter wave（mm Wave） massive MIMO systems. To make better use of directivity gains of the analog beamforming and flexible baseband processing of the digital beamforming, this paper proposes the analog beamforming to select the optimal beam which can maximize the power of the objective user and minimize the interference to all other users. In addition, the digital beamforming maximizes the energy efficiency of the objective user with zero-gradient-based approach. Simulation results show the proposed algorithm provide better bit error rate（BER） performance compared with the traditional hybrid beamforming and obviously improved the sum rate with the increase in the number of users. It is proved that multi-user MIMO（MU-MIMO） can be a perfect candidate for mm Wave massive MIMO communication system. Furthermore, the analog beamforming can mitigate the inter-user interference more effectively with the selection of the optimal beam and the digital beamforming can greatly improve the system performance through flexible baseband processing.展开更多
Intelligent Transport Systems(ITS)are crucial for safety,efficiency,and reduced congestion in transportation.They require efficient,secure,high-speed communication.Radio Frequency(RF)technologies like Fifth Generation...Intelligent Transport Systems(ITS)are crucial for safety,efficiency,and reduced congestion in transportation.They require efficient,secure,high-speed communication.Radio Frequency(RF)technologies like Fifth Generation(5G),Beyond 5G(B5G),and Sixth Generation(6G)are promising,but spectrum scarcity mandates coexistence with Optical Wireless Communication(OWC)networks,which offer high data rates and security,forming a strong foundation for hybrid RF/OWC applications in ITS.In this paper,we delve into the application of Machine Learning(ML)to enhance data communications within OWC systems in ITS.We commence by conducting an in-depth examination of the data communication prerequisites and the associated challenges within the ITS domain.Subsequently,we elucidate the compelling rationale behind the convergence of heterogeneous RF technologies with OWC for data communications in ITS scenarios.Our investigation then pivots towards elucidating the indispensable role played by ML in optimizing data communications via OWC within ITS.To provide a comprehensive perspective,we systematically evaluate and compare a spectrum of ML methodologies employed in OWC ITS data communications.As a culmination of our study,we proffer a set of valuable recommendations and illuminate promising avenues for future research endeavors that warrant further exploration within this critical intersection of ML,OWC,and ITS data communications.展开更多
URL:http://www.infotech.monash.edu.au/about/news/conferences/icsssm08/ Contact email:vincent.lee@infotech.monash.edu.au Conference Theme and Scope The last decade has seen rapid growth of service-based economic activi...URL:http://www.infotech.monash.edu.au/about/news/conferences/icsssm08/ Contact email:vincent.lee@infotech.monash.edu.au Conference Theme and Scope The last decade has seen rapid growth of service-based economic activities in many advanced developed economies such as the USA,European and developed Asian countries as well as emerging展开更多
基金supported in part by the National Natural Science Foundation of China(Nos.62172186,62002133,61872158,61806083)in part by the Key Research of Science and Technology Development Plan Project of Jilin Province,China(No.20240302075GX)+2 种基金in part by the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(No.GZC20240592)in part by the China Postdoctoral Science Foundation General Fund(No.2024M761123)in part by the Scientific Research Project of Jilin Provincial Department of Education,China(No.JJKH20250117KJ).
文摘The maritime communication networks(MCNs)for industry require reliable,efficient,and wide coverage to deploy emerging intelligent marine applications.To this end,unmanned aerial vehicles(UAVs)can be integrated into MCNs to extend flexibility and mobility.However,harsh maritime environments and open line-of-sight(LoS)links increase the UAV onboard energy consumption and worsen communication security.In this work,we aim to propose a collaborative beamforming-based physical layer secure and energy-efficient communication method for UAV-assisted MCNs,in which the energy limitations of UAVs and the interference from both known and unknown eavesdroppers as well as the possible collusion among eavesdroppers are considered.Specifically,we formulate a multi-objective optimization problem(MOP)to improve the system confidentiality rate,reduce the level ratio of the UAV virtual antenna array,and decrease the energy consumption of the UAVs by jointly optimizing the UAV positions and synthesizing the UAV virtual antenna array.This MOP is non-convex and NP-hard,and thus we propose an enhanced non-dominated sorted whale optimization algorithm(ENSWOA)to solve the problem.In ENSWOA,the introduced chaotic solution initialization,adaptive weighting,and optimal position updating methods can increase the searching capability of the algorithm.Simulation results show that the proposed ENSWOA outperforms the baseline algorithms,and can effectively enhance the security and energy efficiency of the considered system.
基金partially the Chongqing Municipality’s Major Theme Project “R & D and Application of 5G terminal simulation equipment” (Grant No. Cstc2017zdcy-zdzx0030)
文摘The initial cell search plays an important role during the process of downlink synchronization establishment between the User Equipment(UE) and the base station. In particular, the uncertainty of the synchronization signals on the frequency domain and the flexibility of frame structure configuration have brought great challenges to the initial cell search for the fifth-generation(5G) new radio(NR). To solve this problem, firstly, we analyze the physical layer frame structure of 5G NR systems. Then, by focusing on the knowledge of synchronization signals, the 5G NR cell search process is designed, and the primary synchronization signal(PSS) timing synchronization algorithm is proposed, including a 5G-based coarse synchronization algorithm and conjugate symmetry-based fine synchronization algorithm. Finally, the performance of the proposed cell search algorithm in 5G NR systems is verified through the combination of Digital Signal Processing(DSP) and personal computer(PC). And the MATLAB simulation proves that the proposed algorithm has better performance than the conventional cross-correlation algorithm when a certain frequency offset exists.
基金The Research and Development for Further Advancement of the 5th Generation Mobile Communication System(No.JP1000254)。
文摘Ultra-densification of radio access network(RAN)is a key to efficiently support the exponentially growing mobile data traffic in 5 G era.Furthermore,extremely high frequency band like mm Wave band was utilized to solve the bandwidth shortage problem.However,untra-dense reusing the same radio resource produced severe interference.And the mm Wave link was very harsh due to frequent blockage by obstacles.Therefore a new RAN architecture needed to be introduced to realize ultra-reliable communications in such a severe radio propagation environment.An architecture of distributed MIMO based RAN was presented.Then,enhanced interference coordination(e IC)was described.Finally,the effectiveness of distributed MIMO based RAN with e IC by computer simulation was showed.
基金supported by the MOST Program of International S&T Cooperation(Grant No.2016YFE0123200)National Natural Science Foundation of China(Grant No.61471100/61101090/61571082)+1 种基金Science and Technology on Electronic Information Control Laboratory(Grant No.6142105040103)Fundamental Research Funds for the Central Universities(Grant No.ZYGX2015J012/ZYGX2014Z005)
文摘Compared to OFDM systems with cyclic prefi x, fi lterbank multicarrier with offset quadrature amplitude modulation(FBMC/OQAM) system is considered as an alternative technology for next generation wireless communication systems. However, FBMC systems suffer from intrinsic imaginary interference caused by the real-fi eld orthogonality destruction when passing through complex-valued fading channels. By analyzing the transmultiplexer's response of FBMC/OQAM systems, in this paper, a simple conjugated transmission scheme is proposed for FBMC/OQAM systems. Following the specific conjugation design, the intrinsic imaginary interference including the intrinsic inter-symbol and the inter-carrier interference can be eliminated at the receiver side through linear signal processing operation. Meanwhile, the proposed conjugated transmission scheme is able to obtain extra linear combination diversity gains for improving the systematic performance of FBMC/OQAM. Simulation results show that the proposed scheme is more efficient than conventional methods, especially in practical application scenarios with large Doppler spread caused by high-speed movement.
文摘On the basis of the first paper’s theoretical derivations and concrete instance calculations of the energies of the d orbitals for a low spin ( S =1/2) nd 5(t 2 5, 2T 2)(n =3, 4, 5) system, the major results reported in this paper contain the following two respects: explicit relationships between the coefficients of the real and complex Kramers doublets have been derived by using two types of the expressions of the principal components of the g tensors in real and complex orbital representations obtained in the first paper; the use of these relationships of the real and complex orbital coefficients has carried out a series of mathematical demonstrations on the agreement of the real and complex orbital methods .
基金This research was supported by National Natural Science Foundation of China(No50575159)Project of Chinese Ministry ofEducation(No106049, 20060056058)Natural Science Foundation of Tianjin (06YFJMJC03400)
文摘This paper investigates the distribution of contact resistance of the aluminum alloy in the squeeze stage. A new method of measuring path＇ s resistance is proposed firstly. Contact resistances are calculated accurately by the systems of 5 linear equations and solutions show that three contact resistances are different. The probability density functions of contact resistance in workpiece/workpiece（ W/W） and upper electrode/workpiece（ E/W） show that the curve shape has steeper peak and heavier tail than that of the normal distribution. Non-parameter hypothesis test is performed and the result shows that R2 , R4 reject the normal distribution using chi-square and kolmogoroo statistic D method. Therefore, the Asymmetric Laplace distribution is fitted to empirical distributions and is applied to quantify the influence of random contact resistance. The result illustrates that AL distribution is very close to contact resistance of W/W and upper E/W and normal distribution has some deviation. The paper is helpful to research the initial nugget conditions, weldability and the transient multi-coupling field.
基金funded by Taif University Researchers Supporting Project No.(TURSP-2020/214),Taif University,Taif,Saudi Arabia。
文摘For a 5G wireless communication system,a convolutional deep neural network(CNN)is employed to synthesize a robust channel state estimator(CSE).The proposed CSE extracts channel information from transmit-and-receive pairs through offline training to estimate the channel state information.Also,it utilizes pilots to offer more helpful information about the communication channel.The proposedCNN-CSE performance is compared with previously published results for Bidirectional/long short-term memory(BiLSTM/LSTM)NNs-based CSEs.The CNN-CSE achieves outstanding performance using sufficient pilots only and loses its functionality at limited pilots compared with BiLSTM and LSTM-based estimators.Using three different loss function-based classification layers and the Adam optimization algorithm,a comparative study was conducted to assess the performance of the presented DNNs-based CSEs.The BiLSTM-CSE outperforms LSTM,CNN,conventional least squares(LS),and minimum mean square error(MMSE)CSEs.In addition,the computational and learning time complexities for DNN-CSEs are provided.These estimators are promising for 5G and future communication systems because they can analyze large amounts of data,discover statistical dependencies,learn correlations between features,and generalize the gotten knowledge.
基金Yayasan UTP,Grant/Award Number:015LC0‐312the Yayasan Universiti Teknologi PETRO-NAS‐Fundamental Research Grant(YUTP‐FRG)-015PBC‐011 for their generous funding of this publication.
文摘In the era of 5G,seamless mobility handovers are critical in densely populated regions like Malaysia to mitigate disruptions and inefficiencies.5G networks offer unprecedented data speeds and reliability,essential for advancing mobile communication and Internet of Things applications.However,ensuring continuous connectivity and service during mobility remains challenging,especially in urban settings.Digital twin technology pre-sents a promising solution to enhance 5G handover mechanisms.A digital twin network(DTN)mirroring Malaysia's 5G infrastructure is proposed,utilising real-time data and user behaviour insights to optimise energy consumption during handovers.The focus is on energy-efficient protocols and algorithms,reviewed through a systematic literature review.The DTN aims to enhance mobility handover efficiency through predictive handovers and adaptive resource allocation,bolstered by sustainable practices such as edge computing.The potential of DTNs to optimise 5G handover processes is explored,starting with the foundational concepts of 5G mobility and digital twins,highlighting the need for improved strategies in high-mobility scenarios.Methodologies leveraging digital twins to predict network conditions,simulate handover scenarios,and proactively manage decisions are examined,reducing latency and packet loss.Case studies demonstrate how digital twins adapt dynamically to network changes and user mobility,thereby improving quality of service and user experience.Malaysia's specific 5G mobility challenges are addressed with a tailored DTN emphasising energy efficiency,evaluated through practical applications.Evaluation criteria assess effectiveness with in-depth analysis of methods,performance metrics,limitations,and recommendations for future research.Challenges and future directions including scalability,security,and real-time data processing,are discussed,aiming to integrate digital twin technology with 5G networks for enhanced connectivity.This abstract provides a roadmap for leveraging digital twins to optimise 5G network performance sustainably,guiding future research and implementation strategies.
基金This work was supported by the National Key R&D Program of the MOST of China(2016YFA0300204)the National Natural Science Foundation of China(11574337,11874199,and 11874263)+2 种基金supported by the National Basic Research Program of China(2015CB654901)Part of this research used Beamline 03U of the Shanghai Synchron Radiation Facility,which is supported by ME2 project(11227902)from the National Natural Science Foundation of Chinasupported by‘‘Award for Outstanding Member in Youth Innovation Promotion Association CAS”。
文摘Electron-boson interaction is fundamental to a thorough understanding of various exotic properties emerging in many-body physics. In photoemission spectroscopy, photoelectron emission due to photon absorption would trigger diverse collective excitations in solids, including the emergence of phonons,magnons, electron-hole pairs, and plasmons, which naturally provides a reliable pathway to study electron-boson couplings. While fingerprints of electron–phonon/-magnon interactions in this state-ofthe-art technique have been well investigated, much less is known about electron-plasmon coupling,and direct observation of the band renormalization solely due to electron-plasmon interactions is extremely challenging. Here by utilizing integrated oxide molecular-beam epitaxy and angle-resolved photoemission spectroscopy, we discover the long sought-after pure electron-plasmon couplinginduced low-lying plasmonic-polaron replica bands in epitaxial semimetallic SrIrO_(3) films, in which the characteristic low carrier concentration and narrow bandwidth combine to provide a unique platform where the electron-plasmon interaction can be investigated kinematically in photoemission spectroscopy. This finding enriches the forms of electron band normalization on collective modes in solids and demonstrates that, to obtain a complete understanding of the quasiparticle dynamics in 5 d electron systems, the electron-plasmon interaction should be considered on equal footing with the acknowledged electron–electron interaction and spin–orbit coupling.
基金supported by the Hi-Tech Research and Development Program of China(2014AA01A705)
文摘The fifth generation mobile communication（5G） systems can provide Gbit/s data rates from massive multiple-input multiple-output（MIMO） combined with the emerging use of millimeter wavelengths in small heterogeneous cells. This paper develops an energy-efficiency based multi-user hybrid beamforming for downlink millimeter wave（mm Wave） massive MIMO systems. To make better use of directivity gains of the analog beamforming and flexible baseband processing of the digital beamforming, this paper proposes the analog beamforming to select the optimal beam which can maximize the power of the objective user and minimize the interference to all other users. In addition, the digital beamforming maximizes the energy efficiency of the objective user with zero-gradient-based approach. Simulation results show the proposed algorithm provide better bit error rate（BER） performance compared with the traditional hybrid beamforming and obviously improved the sum rate with the increase in the number of users. It is proved that multi-user MIMO（MU-MIMO） can be a perfect candidate for mm Wave massive MIMO communication system. Furthermore, the analog beamforming can mitigate the inter-user interference more effectively with the selection of the optimal beam and the digital beamforming can greatly improve the system performance through flexible baseband processing.
文摘Intelligent Transport Systems(ITS)are crucial for safety,efficiency,and reduced congestion in transportation.They require efficient,secure,high-speed communication.Radio Frequency(RF)technologies like Fifth Generation(5G),Beyond 5G(B5G),and Sixth Generation(6G)are promising,but spectrum scarcity mandates coexistence with Optical Wireless Communication(OWC)networks,which offer high data rates and security,forming a strong foundation for hybrid RF/OWC applications in ITS.In this paper,we delve into the application of Machine Learning(ML)to enhance data communications within OWC systems in ITS.We commence by conducting an in-depth examination of the data communication prerequisites and the associated challenges within the ITS domain.Subsequently,we elucidate the compelling rationale behind the convergence of heterogeneous RF technologies with OWC for data communications in ITS scenarios.Our investigation then pivots towards elucidating the indispensable role played by ML in optimizing data communications via OWC within ITS.To provide a comprehensive perspective,we systematically evaluate and compare a spectrum of ML methodologies employed in OWC ITS data communications.As a culmination of our study,we proffer a set of valuable recommendations and illuminate promising avenues for future research endeavors that warrant further exploration within this critical intersection of ML,OWC,and ITS data communications.
文摘URL:http://www.infotech.monash.edu.au/about/news/conferences/icsssm08/ Contact email:vincent.lee@infotech.monash.edu.au Conference Theme and Scope The last decade has seen rapid growth of service-based economic activities in many advanced developed economies such as the USA,European and developed Asian countries as well as emerging
