To explore the technical solution for independently-developed wireless synchronous control of locomotives based on 5G-R,this study investigates the service demands of such control and analyzes the insufficiency of the...To explore the technical solution for independently-developed wireless synchronous control of locomotives based on 5G-R,this study investigates the service demands of such control and analyzes the insufficiency of the existing communication system of China's heavy-haul railway.Giving full consideration of the high bandwidth,low delay,IP-based links,packet domain transmission,quality of service priority guarantee and other characteristics of the 5G-R network,an overall technical solution is proposed,focusing on the implementation of functions such as master-slave locomotive data transmission,controllable end-of-train data transmission,marshaling requests,and multi-driver calls.The findings contribute to enhancing the advancement of the independently-developed wireless synchronous control system of locomotives,ensuring its reliable operation in complex environments,providing valuable guidance for improving the safety and efficiency of heavy-haul railway transportation,and offering robust technical support for the modernization and intelligence development of heavy-haul railway.展开更多
This paper presents a wide-bandwidth back-illuminated modified uni-traveling-carrier photodiode(MUTC-PD)packaged with standard WR-5 rectangular waveguide for high-speed wireless communications.With optimized epitaxy s...This paper presents a wide-bandwidth back-illuminated modified uni-traveling-carrier photodiode(MUTC-PD)packaged with standard WR-5 rectangular waveguide for high-speed wireless communications.With optimized epitaxy structure and coplanar waveguide electrodes,the fabricated 4-μm-diameter PD exhibits ultra-flat frequency response and high saturation power.Integrated passive circuits including low-loss bias-tee and E-plane probe are designed to package the PD into a compact module with waveguide output.The packaged PD module has demonstrated a flat frequency response with fluctuations within±2.75 d B over a broadband of 140–220 GHz and a high saturated output power of-7.8 d Bm(166μW)at 140 GHz.For wireless communication applications,the packaged PD is used to implement 1-m free space transmission at carrier frequencies of 150.5 and 210.5 GHz,with transmission rates of 75 and 90 Gbps,respectively.展开更多
With the advancement of wireless communication technology,intelligent antenna technologies such as beam scanning and beamforming have been extensively applied in operators'5G networks,supported by mature technical...With the advancement of wireless communication technology,intelligent antenna technologies such as beam scanning and beamforming have been extensively applied in operators'5G networks,supported by mature technical solutions.However,the unique characteristics of the railway industry—such as the significant spacing between stations covered by wireless private networks,the high speed of train operations,and the necessity for high network reliability—pose elevated requirements for the construction of 5G private networks.An analysis was conducted on the challenges associated with railway 5G private network coverage.The investigation explored the adaptability of smart antenna technologies in various railway scenarios in combination with the principles and advantages of these technologies.This study analyzed the application prospects of smart antenna technologies in railway 5G private networks,taking into account the characteristics of various train operation scenarios.It evaluated the value of these technologies in enhancing the wireless coverage quality of railway 5G private networks in different scenarios.The findings aim to offer new insights and recommendations for the construction and deployment of railway 5G private networks.展开更多
Terminals and their access represent a vulnerable aspect in the security framework of 5G-railway(5G-R)system.To enhance the control of 5G-R terminals and their access to applications,this paper analyzes the applicatio...Terminals and their access represent a vulnerable aspect in the security framework of 5G-railway(5G-R)system.To enhance the control of 5G-R terminals and their access to applications,this paper analyzes the application scenarios,operational modes,services supported by 5G-R terminals,and the data paths between these terminals and the connected railway application service systems.Further analysis concentrates on the security risks posed by the characteristics of intelligent 5G-R handheld terminals,lightweight Internet of Things(IoT)communication terminals,and onboard integrated wireless transmission equipment with public-private convergence.In light of the risks above,this paper presents the terminal security control requirements.Furthermore,based on the planned architecture of the 5G-R system and security technologies such as terminal identity authentication and behavior auditing,the paper proposes a solution package for the 5G-R terminal security control system,including the overall architecture,functional implementation,and interface configuration.These solutions aim to achieve unified control over the admission and access of 5G-R handheld terminals,IoT communication terminals,and onboard integrated wireless communication equipment to railway application systems.Additionally,they enable the security control and analysis of terminal behaviors and application data,facilitate the security management of terminals,and ensure the secure release,download,and installation of mobile applications.展开更多
The fifth generation(5G) network is expected to support significantly large amount of mobile data traffic and huge number of wireless connections,to achieve better spectrum- and energy-efficiency,as well as quality of...The fifth generation(5G) network is expected to support significantly large amount of mobile data traffic and huge number of wireless connections,to achieve better spectrum- and energy-efficiency,as well as quality of service(QoS) in terms of delay,reliability and security.Furthermore,the 5G network shall also incorporate high mobility requirements as an integral part,providing satisfactory service to users travelling at a speed up to 500 km/h.This paper provides a survey of potential high mobility wireless communication(HMWC) techniques for 5G network.After discussing the typical requirements and challenges of HMWC,key techniques to cope with the challenges are reviewed,including transmission techniques under the fast timevarying channels,network architecture with mobility support,and mobility management.Finally,future research directions on 5G high mobility communications are given.展开更多
Millimeter-wave(mm Wave) communications will be used in fifth-generation(5G) mobile communication systems, but they experience severe path loss and have high sensitivity to physical objects, leading to smaller cell ra...Millimeter-wave(mm Wave) communications will be used in fifth-generation(5G) mobile communication systems, but they experience severe path loss and have high sensitivity to physical objects, leading to smaller cell radii and complicated network architectures. A coverage extension scheme using large-scale antenna arrays(LSAAs) has been suggested and theoretically proven to be cost-efficient in combination with ultradense small cell networks. To analyze and optimize the LSAA-based network deployments, a comprehensive survey of recent advances in statistical mmWave channel modeling is first presented in terms of channel parameter estimation, large-scale path loss models, and small-scale cluster models. Next, the measurement and modeling results at two 5G candidate mmWave bands(e.g., 28 GHz and 39 GHz) are reviewed and compared in several outdoor scenarios of interest, where the propagation characteristics make crucial contributions to wireless network designs. Finally, the coverage behaviors of systems employing a large number of antenna arrays are discussed, as well as some implications on future mmWave cellular network designs.展开更多
The fifth generation （5G） wireless communication is currently a hot research topic and wireless communication systems on high speed railways （HSR） are important applications of 5G technologies. Existing stud- ies ...The fifth generation （5G） wireless communication is currently a hot research topic and wireless communication systems on high speed railways （HSR） are important applications of 5G technologies. Existing stud- ies about 5G wireless systems on high speed railways （HSR） often utilize ideal channel parameters and are usually based on simple scenarios. In this paper, we evaluate the down- link throughput of 5G HSR communication systems on three typical scenarios including urban, cutting and viaduct with three different channel estimators. The channel parameters of each scenario are generated with tapped delay line （TDL） models through ray-tracing sim- ulations, which can be considered as a good match to practical situations. The channel estimators including least square （LS）, linear minimum mean square error （LMMSE）, and our proposed historical information based ba- sis expansion model （HiBEM）. We analyze the performance of the HiBEM estimator in terms of mean square error （MSE） and evaluate the system throughputs with different channel estimates over each scenario. Simulation results are then provided to corroborate our proposed studies. It is shown that our HiBEM estimator outperforms other estimators and that the sys-tem throughput can reach the highest point in the viaduct scenario.展开更多
This paper focuses on the design and implementation of an active multibeam antenna system for massive MIMO applications in 5G wireless communications.The highly integrated active multibeam antenna system is designed a...This paper focuses on the design and implementation of an active multibeam antenna system for massive MIMO applications in 5G wireless communications.The highly integrated active multibeam antenna system is designed and implemented at 5.8 GHz with 64 RF Channels and 256 antenna elements.The 64-channel highly integrated active multibeam antenna system provides a verification platform for digital beamforming algorithm and massive MIMO channel estimation for next generation wireless communications.展开更多
The development of science and technology is the key to changing human life and promoting social and economic development.As a product of technological development,the widespread application of communication technolog...The development of science and technology is the key to changing human life and promoting social and economic development.As a product of technological development,the widespread application of communication technology has brought a brand new“dawn”to the development of human society.5G wireless communication technology is an advanced wireless communication technology that has recently developed.With the advantages of low energy consumption and high network speed,5G technology has shown very bright development prospects in various fields today.Government,operators and equipment providers are actively promoting and deploying 5G technology,and all links in the industry chain are mature.It is expected that the future market size will reach 17 trillion,especially in today’s industrial field,the application of 5G technology will further enhance work efficiency,ensure work quality,and promote good development in the industrial field.Based on this,this paper will study the development of 5G wireless technology in the industrial field,so as to provide corresponding reference for the good application of 5G technology in the industrial field.展开更多
This paper presents the single element dual band switched beam textile antenna.The antenna can operate at frequencies of 0.7 and 2.6 GHz using for 5G wireless communication applications.Textile fabric is considered to...This paper presents the single element dual band switched beam textile antenna.The antenna can operate at frequencies of 0.7 and 2.6 GHz using for 5G wireless communication applications.Textile fabric is considered to be used for substrate layer at the parts of a microstrip antenna for wireless body area network.The beam pattern of antenna can be switched into two directions by changing the position of shorted-circuit points at each edge of antenna.The main beam direction is 45°/225°when corner A is shorted while it steers at 135°/315°when corner B is shorted circuit.The advantage of the proposed antenna is the decrease of the problems like interference,light weight,flexibility and ability to switch beam easily.In addition,the results of the fabricated antenna are compared with the simulated ones.Moreover,the antenna is bent with curvature radius of 6 mm in forward direction.The effects of the bent antenna are studied.The results can confirm that radiation patterns of the bending antenna can be pointed into two directions when changing the positions of shorted circuit.Therefore,the proposed antenna can switch beam patterns,it is flexible,and it can operate at dual-band frequency on textile.展开更多
The development momentum of wireless communication technology is strong. The development of wireless communication not only provides some convenience for peoples daily life, but also has a great influence on peoples d...The development momentum of wireless communication technology is strong. The development of wireless communication not only provides some convenience for peoples daily life, but also has a great influence on peoples daily behavior. Under the current development trend, 5G is the main technology in the future, which will inevitably bring richer user experiences. Therefore, on this basis, the development and application of 5G technology in the new era are introduced in detail.展开更多
Since around 1980,a new generation of wireless technology has arisen approximately every 10 years.First-generation(1G)and secondgeneration(2G)began with voice and eventually introduced more and more data in third-gene...Since around 1980,a new generation of wireless technology has arisen approximately every 10 years.First-generation(1G)and secondgeneration(2G)began with voice and eventually introduced more and more data in third-generation(3G)and became highly popular in the fourthgeneration(4G).To increase the data rate along with low latency and mass connectivity the fifth-generation(5G)networks are being installed from 2020.However,the 5G technology will not be able to fulfill the data demand at the end of this decade.Therefore,it is expected that 6G communication networks will rise,providing better services through the implementation of new enabling technologies and allowing users to connect everywhere.6G technology would not be confined to cellular communications networks,but would also comply with non-terrestrial communication system requirements,such as satellite communication.The ultimate objectives of this work are to address the major challenges of the evolution of cellular communication networks and to discourse the recent growth of the industry based on the key scopes of application and challenges.The main areas of research topics are summarized into(i)major 6G wireless networkmilestones;(ii)key performance indicators;(iii)future new applications;and(iv)potential fields of research,challenges,and open issues.展开更多
This paper analyzes the communication business needs and application characteristics based on China's railway operation scenarios.Focusing on the specific needs of railways,the 5G-Railway(5G-R)system adds railway-...This paper analyzes the communication business needs and application characteristics based on China's railway operation scenarios.Focusing on the specific needs of railways,the 5G-Railway(5G-R)system adds railway-specific functional network elements on the basis of general architecture.In terms of system networking,it focuses on the innovative key technologies of 5G-R core network and wireless network networking to adapt to the railway management mechanism and reliability requirements.It analyzes the technical optimization and innovation of 5G-R railway common equipment in terms of redundancy mode,function sinking,fault detection and reversal mechanism,etc.;5G-R wireless network adopts the same-site equipment redundancy mode,and the paper analyzes the technological innovation of RRU redundancy,BBU redundancy and PCI planning,etc.;it also highlights the benefits of the train-ground integrated transmission system,including reduced roof antennas,decoupling of services and communication,unified spatial and temporal benchmarks,and cost savings.展开更多
Future networks communication scenarios by the 2030s will include notable applications are three-dimensional(3D)calls,haptics communications,unmanned mobility,tele-operated driving,bio-internet of things,and the Nanoi...Future networks communication scenarios by the 2030s will include notable applications are three-dimensional(3D)calls,haptics communications,unmanned mobility,tele-operated driving,bio-internet of things,and the Nanointernet of things.Unlike the current scenario in which megahertz bandwidth are sufficient to drive the audio and video components of user applications,the future networks of the 2030s will require bandwidths in several gigahertzes(GHz)(from tens of gigahertz to 1 terahertz[THz])to perform optimally.Based on the current radio frequency allocation chart,it is not possible to obtain such a wide contiguous radio spectrum below 90 GHz(0.09 THz).Interestingly,these contiguous blocks of radio spectrum are readily available in the higher electromagnetic spectrum,specifically in the Terahertz(THz)frequency band.The major contribution of this study is discussing the substantial issues and key features of THz waves,which include(i)key features and significance of THz frequency;(ii)recent regulatory;(iii)the most promising applications;and(iv)possible open research issues.These research topics were deeply investigated with the aim of providing a specific,synopsis,and encompassing conclusion.Thus,this article will be as a catalyst towards exploring new frontiers for future networks of the 2030s.展开更多
It is undeniable that wireless communication technology has become a very important component of modern society. One aspect of modern society in which application of wireless communication technologies has tremendous ...It is undeniable that wireless communication technology has become a very important component of modern society. One aspect of modern society in which application of wireless communication technologies has tremendous potential is in agricultural production. This is especially true in the area of sensing and transmission of relevant farming information such as weather, crop development, water quantity and quality, among others, which would allow farmers to make more accurate and timely farming decisions. A good example would be the application of wireless communication technology to transmit soil moisture data in real time to help farmers make irrigation scheduling decisions. Although many systems are commercially available for soil moisture monitoring, there are still many important factors, such as cost, limiting widespread adoption of this technology among growers. Our objective in this study was, therefore, to develop and test an affordable wireless communication system for monitoring soil moisture using Decagon EC-5 sensors. The new system uses Arduino-compatible microcontrollers and communication systems to sample and transmit values from four Decagon EC-5 soil moisture sensors. Developing the system required conducting lab calibrations for the EC-5 sensors for the microcontroller operating in either 10-bit or 12-bit analog-to-digital converter (ADC) resolution. The system was successfully tested in the field and reliably collected and transmitted data from a wheat field for more than two months.展开更多
Road transport is been used for moving people and all kinds of goods throughout the world. However, it is one mode of transportation that is prone to accidents and it faces a plethora of never-ending challenges, such ...Road transport is been used for moving people and all kinds of goods throughout the world. However, it is one mode of transportation that is prone to accidents and it faces a plethora of never-ending challenges, such as the frequent loss of lives and valuables when accident occurs. The best course of action to handle these issues is to set up an autonomous incident detection system using wireless communication, 5G technologies and the Internet of Things. IoT is a seamless technology that increases the connectivity between humans and machines. It is web-based, and improves communication between vehicle to vehicle, vehicle to infrastructures, transfer of data and information to predict incident occurrences through various networks and frameworks such as eCall, OneM2M and integration of mobile broadband. Additionally, internet of things is being adopted for public safety;for instance, it can speed up first responders’ response times to situations by displaying the best routes to a scene of an accident. The rapid development of 5G is happening in parallel with developments of internet of things (IoT), artificial intelligence (AI), and smart platforms for novel applications such as mission-critical communications. 5G is a new generation technology that operates on the Ultra High Spectrum Band UHSB. It is an innovation that uses the pedestrians-vehicle-road-cloud, and the communication between vehicle locations and temperature of high-quality connection. It is essential for intelligent transport systems because it allows for information sharing, prediction of incidences as safety is the primary concern of road transport. This review examines accident detection through 5G technology, integrated mobile broadband, and multiple inputs multiple outputs (MIMO) wireless system. Finally, we conclude by examining recent technology, challenges, present and future research trends.展开更多
Purpose–As the strategy of 5G new infrastructure is deployed and advanced,5G-R becomes the primary technical system for future mobile communication of China’s railway.V2V communication is also an important applicati...Purpose–As the strategy of 5G new infrastructure is deployed and advanced,5G-R becomes the primary technical system for future mobile communication of China’s railway.V2V communication is also an important application scenario of 5G communication systems on high-speed railways,so time synchronization between vehicles is critical for train control systems to be real-time and safe.How to improve the time synchronization performance in V2V communication is crucial to ensure the operational safety and efficiency of high-speed railways.Design/methodology/approach–This paper proposed a time synchronization method based on model predictive control(MPC)for V2V communication.Firstly,a synchronous clock for V2V communication was modeled based on the fifth generation mobile communication-railway(5G-R)system.Secondly,an observation equation was introduced according to the phase and frequency offsets between synchronous clocks of two adjacent vehicles to construct an MPC-based space model of clock states of the adjacent vehicles.Finally,the optimal clock offset was solved through multistep prediction,rolling optimization and other control methods,and time synchronization in different V2V communication scenarios based on the 5G-R system was realized through negative feedback correction.Findings–The results of simulation tests conducted with and without a repeater,respectively,show that the proposed method can realize time synchronization of V2V communication in both scenarios.Compared with other methods,the proposed method has faster convergence speed and higher synchronization precision regardless of whether there is a repeater or not.Originality/value–This paper proposed an MPC-based time synchronization method for V2V communication under 5G-R.Through the construction of MPC controllers for clocks of adjacent vehicles,time synchronization was realized for V2V communication under 5G-R by using control means such as multistep prediction,rolling optimization,and feedback correction.In view of the problems of low synchronization precision and slow convergence speed caused by packet loss with existing synchronization methods,the observer equation was introduced to estimate the clock state of the adjacent vehicles in case of packet loss,which reduces the impact of clock error caused by packet loss in the synchronization process and improves the synchronization precision of V2V communication.The research results provide some theoretical references for V2V synchronous wireless communication under 5G-R technology.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
Network functions virtualization(NFV) increases network flexibility and scalability by virtualizing network functions running on the general servers and opens the network innovations by outsourcing VNF instances in 5G...Network functions virtualization(NFV) increases network flexibility and scalability by virtualizing network functions running on the general servers and opens the network innovations by outsourcing VNF instances in 5G networks.However,it leads to the incompatibility issue among different VNF instances,which makes operators difficult to determine which VNF instances to select for Service Function Chains(SFCs).In this paper,we divide VNF instances with high compatibility into clusters used for combining VNF instances in 5G networks.Firstly,we define compatibility among different VNF instances.Secondly,aiming to maximize compatibility of each cluster,we propose a novel hypergraph clustering model that divides the VNF instances into multiple clusters.Then,the hypergraph clustering model is transformed to an evolutionary game.Thus,the cluster establishing is transformed to the game equilibrium searching.Furthermore,we propose a discrete time high order replicator dynamic algorithm to find the game equilibrium.Finally,the simulation results show that the proposed approach can improve the quality of SFCs.展开更多
文摘To explore the technical solution for independently-developed wireless synchronous control of locomotives based on 5G-R,this study investigates the service demands of such control and analyzes the insufficiency of the existing communication system of China's heavy-haul railway.Giving full consideration of the high bandwidth,low delay,IP-based links,packet domain transmission,quality of service priority guarantee and other characteristics of the 5G-R network,an overall technical solution is proposed,focusing on the implementation of functions such as master-slave locomotive data transmission,controllable end-of-train data transmission,marshaling requests,and multi-driver calls.The findings contribute to enhancing the advancement of the independently-developed wireless synchronous control system of locomotives,ensuring its reliable operation in complex environments,providing valuable guidance for improving the safety and efficiency of heavy-haul railway transportation,and offering robust technical support for the modernization and intelligence development of heavy-haul railway.
基金supported in part by National Key Research and Development Program of China(No.2022YFB2803002)National Natural Science Foundation of China(Nos.62235005,62127814,62225405,61975093,61927811,61991443,61925104 and 61974080)Collaborative Innovation Centre of Solid-State Lighting and Energy-Saving Electronics.
文摘This paper presents a wide-bandwidth back-illuminated modified uni-traveling-carrier photodiode(MUTC-PD)packaged with standard WR-5 rectangular waveguide for high-speed wireless communications.With optimized epitaxy structure and coplanar waveguide electrodes,the fabricated 4-μm-diameter PD exhibits ultra-flat frequency response and high saturation power.Integrated passive circuits including low-loss bias-tee and E-plane probe are designed to package the PD into a compact module with waveguide output.The packaged PD module has demonstrated a flat frequency response with fluctuations within±2.75 d B over a broadband of 140–220 GHz and a high saturated output power of-7.8 d Bm(166μW)at 140 GHz.For wireless communication applications,the packaged PD is used to implement 1-m free space transmission at carrier frequencies of 150.5 and 210.5 GHz,with transmission rates of 75 and 90 Gbps,respectively.
文摘With the advancement of wireless communication technology,intelligent antenna technologies such as beam scanning and beamforming have been extensively applied in operators'5G networks,supported by mature technical solutions.However,the unique characteristics of the railway industry—such as the significant spacing between stations covered by wireless private networks,the high speed of train operations,and the necessity for high network reliability—pose elevated requirements for the construction of 5G private networks.An analysis was conducted on the challenges associated with railway 5G private network coverage.The investigation explored the adaptability of smart antenna technologies in various railway scenarios in combination with the principles and advantages of these technologies.This study analyzed the application prospects of smart antenna technologies in railway 5G private networks,taking into account the characteristics of various train operation scenarios.It evaluated the value of these technologies in enhancing the wireless coverage quality of railway 5G private networks in different scenarios.The findings aim to offer new insights and recommendations for the construction and deployment of railway 5G private networks.
文摘Terminals and their access represent a vulnerable aspect in the security framework of 5G-railway(5G-R)system.To enhance the control of 5G-R terminals and their access to applications,this paper analyzes the application scenarios,operational modes,services supported by 5G-R terminals,and the data paths between these terminals and the connected railway application service systems.Further analysis concentrates on the security risks posed by the characteristics of intelligent 5G-R handheld terminals,lightweight Internet of Things(IoT)communication terminals,and onboard integrated wireless transmission equipment with public-private convergence.In light of the risks above,this paper presents the terminal security control requirements.Furthermore,based on the planned architecture of the 5G-R system and security technologies such as terminal identity authentication and behavior auditing,the paper proposes a solution package for the 5G-R terminal security control system,including the overall architecture,functional implementation,and interface configuration.These solutions aim to achieve unified control over the admission and access of 5G-R handheld terminals,IoT communication terminals,and onboard integrated wireless communication equipment to railway application systems.Additionally,they enable the security control and analysis of terminal behaviors and application data,facilitate the security management of terminals,and ensure the secure release,download,and installation of mobile applications.
基金supported by the National Basic Research Program of China (973 Program No.2012CB316100)
文摘The fifth generation(5G) network is expected to support significantly large amount of mobile data traffic and huge number of wireless connections,to achieve better spectrum- and energy-efficiency,as well as quality of service(QoS) in terms of delay,reliability and security.Furthermore,the 5G network shall also incorporate high mobility requirements as an integral part,providing satisfactory service to users travelling at a speed up to 500 km/h.This paper provides a survey of potential high mobility wireless communication(HMWC) techniques for 5G network.After discussing the typical requirements and challenges of HMWC,key techniques to cope with the challenges are reviewed,including transmission techniques under the fast timevarying channels,network architecture with mobility support,and mobility management.Finally,future research directions on 5G high mobility communications are given.
基金supported in part by the National Natural Science Foundation of China under Grant No.61671145the Key R&D Program of Jiangsu Province of China under Grant BE2018121
文摘Millimeter-wave(mm Wave) communications will be used in fifth-generation(5G) mobile communication systems, but they experience severe path loss and have high sensitivity to physical objects, leading to smaller cell radii and complicated network architectures. A coverage extension scheme using large-scale antenna arrays(LSAAs) has been suggested and theoretically proven to be cost-efficient in combination with ultradense small cell networks. To analyze and optimize the LSAA-based network deployments, a comprehensive survey of recent advances in statistical mmWave channel modeling is first presented in terms of channel parameter estimation, large-scale path loss models, and small-scale cluster models. Next, the measurement and modeling results at two 5G candidate mmWave bands(e.g., 28 GHz and 39 GHz) are reviewed and compared in several outdoor scenarios of interest, where the propagation characteristics make crucial contributions to wireless network designs. Finally, the coverage behaviors of systems employing a large number of antenna arrays are discussed, as well as some implications on future mmWave cellular network designs.
基金supported by the National Natural Science Foundation of China(Grant Nos.61522109,61671253,61571037and 91738201)the Fundamental Research Funds for the Central Universities(No.2016JBZ006)+1 种基金the Natural Science Foundation of Jiangsu Province(Grant Nos.BK20150040and BK20171446)the Key Project of Natural Science Research of Higher Education Institutions of Jiangsu Province(No.15KJA510003)
文摘The fifth generation （5G） wireless communication is currently a hot research topic and wireless communication systems on high speed railways （HSR） are important applications of 5G technologies. Existing stud- ies about 5G wireless systems on high speed railways （HSR） often utilize ideal channel parameters and are usually based on simple scenarios. In this paper, we evaluate the down- link throughput of 5G HSR communication systems on three typical scenarios including urban, cutting and viaduct with three different channel estimators. The channel parameters of each scenario are generated with tapped delay line （TDL） models through ray-tracing sim- ulations, which can be considered as a good match to practical situations. The channel estimators including least square （LS）, linear minimum mean square error （LMMSE）, and our proposed historical information based ba- sis expansion model （HiBEM）. We analyze the performance of the HiBEM estimator in terms of mean square error （MSE） and evaluate the system throughputs with different channel estimates over each scenario. Simulation results are then provided to corroborate our proposed studies. It is shown that our HiBEM estimator outperforms other estimators and that the sys-tem throughput can reach the highest point in the viaduct scenario.
文摘This paper focuses on the design and implementation of an active multibeam antenna system for massive MIMO applications in 5G wireless communications.The highly integrated active multibeam antenna system is designed and implemented at 5.8 GHz with 64 RF Channels and 256 antenna elements.The 64-channel highly integrated active multibeam antenna system provides a verification platform for digital beamforming algorithm and massive MIMO channel estimation for next generation wireless communications.
文摘The development of science and technology is the key to changing human life and promoting social and economic development.As a product of technological development,the widespread application of communication technology has brought a brand new“dawn”to the development of human society.5G wireless communication technology is an advanced wireless communication technology that has recently developed.With the advantages of low energy consumption and high network speed,5G technology has shown very bright development prospects in various fields today.Government,operators and equipment providers are actively promoting and deploying 5G technology,and all links in the industry chain are mature.It is expected that the future market size will reach 17 trillion,especially in today’s industrial field,the application of 5G technology will further enhance work efficiency,ensure work quality,and promote good development in the industrial field.Based on this,this paper will study the development of 5G wireless technology in the industrial field,so as to provide corresponding reference for the good application of 5G technology in the industrial field.
基金This work is funded from the Thailand Science Research and Innovation through the research grant No.036/2564,https://www.tsri.or.th/.
文摘This paper presents the single element dual band switched beam textile antenna.The antenna can operate at frequencies of 0.7 and 2.6 GHz using for 5G wireless communication applications.Textile fabric is considered to be used for substrate layer at the parts of a microstrip antenna for wireless body area network.The beam pattern of antenna can be switched into two directions by changing the position of shorted-circuit points at each edge of antenna.The main beam direction is 45°/225°when corner A is shorted while it steers at 135°/315°when corner B is shorted circuit.The advantage of the proposed antenna is the decrease of the problems like interference,light weight,flexibility and ability to switch beam easily.In addition,the results of the fabricated antenna are compared with the simulated ones.Moreover,the antenna is bent with curvature radius of 6 mm in forward direction.The effects of the bent antenna are studied.The results can confirm that radiation patterns of the bending antenna can be pointed into two directions when changing the positions of shorted circuit.Therefore,the proposed antenna can switch beam patterns,it is flexible,and it can operate at dual-band frequency on textile.
文摘The development momentum of wireless communication technology is strong. The development of wireless communication not only provides some convenience for peoples daily life, but also has a great influence on peoples daily behavior. Under the current development trend, 5G is the main technology in the future, which will inevitably bring richer user experiences. Therefore, on this basis, the development and application of 5G technology in the new era are introduced in detail.
基金This research was supported by the National Research Foundation(NRF),Korea(2019R1C1C1007277)funded by the Ministry of Science and ICT(MSIT),Korea.
文摘Since around 1980,a new generation of wireless technology has arisen approximately every 10 years.First-generation(1G)and secondgeneration(2G)began with voice and eventually introduced more and more data in third-generation(3G)and became highly popular in the fourthgeneration(4G).To increase the data rate along with low latency and mass connectivity the fifth-generation(5G)networks are being installed from 2020.However,the 5G technology will not be able to fulfill the data demand at the end of this decade.Therefore,it is expected that 6G communication networks will rise,providing better services through the implementation of new enabling technologies and allowing users to connect everywhere.6G technology would not be confined to cellular communications networks,but would also comply with non-terrestrial communication system requirements,such as satellite communication.The ultimate objectives of this work are to address the major challenges of the evolution of cellular communication networks and to discourse the recent growth of the industry based on the key scopes of application and challenges.The main areas of research topics are summarized into(i)major 6G wireless networkmilestones;(ii)key performance indicators;(iii)future new applications;and(iv)potential fields of research,challenges,and open issues.
文摘This paper analyzes the communication business needs and application characteristics based on China's railway operation scenarios.Focusing on the specific needs of railways,the 5G-Railway(5G-R)system adds railway-specific functional network elements on the basis of general architecture.In terms of system networking,it focuses on the innovative key technologies of 5G-R core network and wireless network networking to adapt to the railway management mechanism and reliability requirements.It analyzes the technical optimization and innovation of 5G-R railway common equipment in terms of redundancy mode,function sinking,fault detection and reversal mechanism,etc.;5G-R wireless network adopts the same-site equipment redundancy mode,and the paper analyzes the technological innovation of RRU redundancy,BBU redundancy and PCI planning,etc.;it also highlights the benefits of the train-ground integrated transmission system,including reduced roof antennas,decoupling of services and communication,unified spatial and temporal benchmarks,and cost savings.
基金the Research Program through the National Research Foundation of Korea(NRF-2019R1A2C1005920).
文摘Future networks communication scenarios by the 2030s will include notable applications are three-dimensional(3D)calls,haptics communications,unmanned mobility,tele-operated driving,bio-internet of things,and the Nanointernet of things.Unlike the current scenario in which megahertz bandwidth are sufficient to drive the audio and video components of user applications,the future networks of the 2030s will require bandwidths in several gigahertzes(GHz)(from tens of gigahertz to 1 terahertz[THz])to perform optimally.Based on the current radio frequency allocation chart,it is not possible to obtain such a wide contiguous radio spectrum below 90 GHz(0.09 THz).Interestingly,these contiguous blocks of radio spectrum are readily available in the higher electromagnetic spectrum,specifically in the Terahertz(THz)frequency band.The major contribution of this study is discussing the substantial issues and key features of THz waves,which include(i)key features and significance of THz frequency;(ii)recent regulatory;(iii)the most promising applications;and(iv)possible open research issues.These research topics were deeply investigated with the aim of providing a specific,synopsis,and encompassing conclusion.Thus,this article will be as a catalyst towards exploring new frontiers for future networks of the 2030s.
文摘It is undeniable that wireless communication technology has become a very important component of modern society. One aspect of modern society in which application of wireless communication technologies has tremendous potential is in agricultural production. This is especially true in the area of sensing and transmission of relevant farming information such as weather, crop development, water quantity and quality, among others, which would allow farmers to make more accurate and timely farming decisions. A good example would be the application of wireless communication technology to transmit soil moisture data in real time to help farmers make irrigation scheduling decisions. Although many systems are commercially available for soil moisture monitoring, there are still many important factors, such as cost, limiting widespread adoption of this technology among growers. Our objective in this study was, therefore, to develop and test an affordable wireless communication system for monitoring soil moisture using Decagon EC-5 sensors. The new system uses Arduino-compatible microcontrollers and communication systems to sample and transmit values from four Decagon EC-5 soil moisture sensors. Developing the system required conducting lab calibrations for the EC-5 sensors for the microcontroller operating in either 10-bit or 12-bit analog-to-digital converter (ADC) resolution. The system was successfully tested in the field and reliably collected and transmitted data from a wheat field for more than two months.
文摘Road transport is been used for moving people and all kinds of goods throughout the world. However, it is one mode of transportation that is prone to accidents and it faces a plethora of never-ending challenges, such as the frequent loss of lives and valuables when accident occurs. The best course of action to handle these issues is to set up an autonomous incident detection system using wireless communication, 5G technologies and the Internet of Things. IoT is a seamless technology that increases the connectivity between humans and machines. It is web-based, and improves communication between vehicle to vehicle, vehicle to infrastructures, transfer of data and information to predict incident occurrences through various networks and frameworks such as eCall, OneM2M and integration of mobile broadband. Additionally, internet of things is being adopted for public safety;for instance, it can speed up first responders’ response times to situations by displaying the best routes to a scene of an accident. The rapid development of 5G is happening in parallel with developments of internet of things (IoT), artificial intelligence (AI), and smart platforms for novel applications such as mission-critical communications. 5G is a new generation technology that operates on the Ultra High Spectrum Band UHSB. It is an innovation that uses the pedestrians-vehicle-road-cloud, and the communication between vehicle locations and temperature of high-quality connection. It is essential for intelligent transport systems because it allows for information sharing, prediction of incidences as safety is the primary concern of road transport. This review examines accident detection through 5G technology, integrated mobile broadband, and multiple inputs multiple outputs (MIMO) wireless system. Finally, we conclude by examining recent technology, challenges, present and future research trends.
基金supported by the National Natural Science Foundation of China(Grant Nos.61963023&61841303)the Tianyou Innovation Team Science Foundation of Lanzhou Jiaotong University(Grant No.TY202003).
文摘Purpose–As the strategy of 5G new infrastructure is deployed and advanced,5G-R becomes the primary technical system for future mobile communication of China’s railway.V2V communication is also an important application scenario of 5G communication systems on high-speed railways,so time synchronization between vehicles is critical for train control systems to be real-time and safe.How to improve the time synchronization performance in V2V communication is crucial to ensure the operational safety and efficiency of high-speed railways.Design/methodology/approach–This paper proposed a time synchronization method based on model predictive control(MPC)for V2V communication.Firstly,a synchronous clock for V2V communication was modeled based on the fifth generation mobile communication-railway(5G-R)system.Secondly,an observation equation was introduced according to the phase and frequency offsets between synchronous clocks of two adjacent vehicles to construct an MPC-based space model of clock states of the adjacent vehicles.Finally,the optimal clock offset was solved through multistep prediction,rolling optimization and other control methods,and time synchronization in different V2V communication scenarios based on the 5G-R system was realized through negative feedback correction.Findings–The results of simulation tests conducted with and without a repeater,respectively,show that the proposed method can realize time synchronization of V2V communication in both scenarios.Compared with other methods,the proposed method has faster convergence speed and higher synchronization precision regardless of whether there is a repeater or not.Originality/value–This paper proposed an MPC-based time synchronization method for V2V communication under 5G-R.Through the construction of MPC controllers for clocks of adjacent vehicles,time synchronization was realized for V2V communication under 5G-R by using control means such as multistep prediction,rolling optimization,and feedback correction.In view of the problems of low synchronization precision and slow convergence speed caused by packet loss with existing synchronization methods,the observer equation was introduced to estimate the clock state of the adjacent vehicles in case of packet loss,which reduces the impact of clock error caused by packet loss in the synchronization process and improves the synchronization precision of V2V communication.The research results provide some theoretical references for V2V synchronous wireless communication under 5G-R technology.
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.
基金supported by The National High Technology Research and Development Program of China(863)(Grant No.2014AA01A701,2015AA01A706)
文摘Network functions virtualization(NFV) increases network flexibility and scalability by virtualizing network functions running on the general servers and opens the network innovations by outsourcing VNF instances in 5G networks.However,it leads to the incompatibility issue among different VNF instances,which makes operators difficult to determine which VNF instances to select for Service Function Chains(SFCs).In this paper,we divide VNF instances with high compatibility into clusters used for combining VNF instances in 5G networks.Firstly,we define compatibility among different VNF instances.Secondly,aiming to maximize compatibility of each cluster,we propose a novel hypergraph clustering model that divides the VNF instances into multiple clusters.Then,the hypergraph clustering model is transformed to an evolutionary game.Thus,the cluster establishing is transformed to the game equilibrium searching.Furthermore,we propose a discrete time high order replicator dynamic algorithm to find the game equilibrium.Finally,the simulation results show that the proposed approach can improve the quality of SFCs.
