This paper derives a non-stationary multiple-input multiple-output(MIMO) from the one-ring scattering model. The proposed channel model characterizes vehicular radio propagation channels with considerations of moving ...This paper derives a non-stationary multiple-input multiple-output(MIMO) from the one-ring scattering model. The proposed channel model characterizes vehicular radio propagation channels with considerations of moving base and mobile stations, which makes the angle of arrivals(AOAs) along with the angle of departures(AODs) time-variant. We introduce the methodology of including the time-variant impacts when characterizing non-stationary radio propagation channels through the geometrical channel modelling approach. We analyze the statistical properties of the proposed channel model including the local time-variant autocorrelation function(ACF) and the space cross-correlation functions(CCFs). We show that the model developed in this paper for non-stationary scenarios includes the existing one-ring wide-sense stationary channel model as its special case.展开更多
This paper investigates the resource scheduling for heterogeneous vehicular networks, where some moving vehicles are selected and scheduled as helping relays to assist information transmission between the roadside inf...This paper investigates the resource scheduling for heterogeneous vehicular networks, where some moving vehicles are selected and scheduled as helping relays to assist information transmission between the roadside infrastructure and other moving vehicles. For such a system, we propose a mobile-service based max-min fairness resource scheduling scheme, where service amount which is more suitable for high mobility scenarios is adopted to characterize the information transmission capacity of the links and the max-min criteria is adopted to meet the fairness requirement of the moving vehicles. Simulation results demonstrate the effectiveness of our proposed scheme. It is shown that our proposed scheme archives higher throughput and better fairness compared with random scheduling scheme and non-relaying scheme.展开更多
Vehicle-to-vehicle(V2V)communication appeals to increasing research interest as a result of its applications to provide safety information as well as infotainment services.The increasing demand of transmit rates and v...Vehicle-to-vehicle(V2V)communication appeals to increasing research interest as a result of its applications to provide safety information as well as infotainment services.The increasing demand of transmit rates and various requirements of quality of services(QoS)in vehicular communication scenarios call for the integration of V2V communication systems and potential techniques in the future wireless communications,such as full duplex(FD)and non-orthogonal multiple access(NOMA)which enhance spectral efficiency and provide massive connectivity.However,the large amount of data transmission and user connectivity give rise to the concern of security issues and personal privacy.In order to analyze the security performance of V2V communications,we introduce a cooperative NOMA V2V system model with an FD relay.This paper focuses on the security performance of the FD-NOMA based V2V system on the physical layer perspective.We first derive several analytical results of the ergodic secrecy capacity.Then,we propose a secrecy sum rate optimization scheme utilizing the instantaneous channel state information(CSI),which is formulated as a non-convex optimization problem.Based on the differential structure of the non-convex constraints,the original problem is approximated and solved by a series of convex optimization problems.Simulation results validate the analytical results and the effectiveness of the secrecy sum rate optimization algorithm.展开更多
Vehicular Ad-hoc Networks(VANETs) require reliable data dissemination for time-sensitive public safety applications. An efficient routing protocol plays a vital role to achieve satisfactory network performance. It is ...Vehicular Ad-hoc Networks(VANETs) require reliable data dissemination for time-sensitive public safety applications. An efficient routing protocol plays a vital role to achieve satisfactory network performance. It is well known that routing is a challenging problem in VANETs due to the fast-changing network typology caused by high mobility at both ends of transmission. Moreover, under urban environment, there are two non-negligible factors in routing protocol design, the non-uniform vehicle distribution caused by traffic lights, and the network congestion due to high traffic demand in rush hours. In this paper, we propose a greedy traffic light and queue aware routing protocol(GTLQR) which jointly considers the street connectivity, channel quality, relative distance, and queuing delay to alleviate the packet loss caused by vehicle clustering at the intersection and balance the traffic load among vehicles. Through performance evaluation, we show that our proposed protocol outperforms both TLRC and GLSR-L in terms of packet delivery ratio and end-to-end delay.展开更多
When there is an increasing interest in visible light communication(VLC), outdoor vehicle VLC has emerged as a promising candidate technology for future intelligent transportation systems. However, in VLC based vehicu...When there is an increasing interest in visible light communication(VLC), outdoor vehicle VLC has emerged as a promising candidate technology for future intelligent transportation systems. However, in VLC based vehicular applications, several challenges impede successful commercial application of VLC based products. This article first provides a thorough overview of the existing challenges. To overcome these challenges, we propose a novel architecture with tracking and environment sensing ability for practical vehicular applications. Moreover, a proof-ofconcept prototype is implemented to validate the feasibility of the proposed system. Experimental and simulation results show that the proposed VLC system can provide reliable communications with a bit-error rate less than 10-4for vehicles under strong interference lights. Finally, based on the evaluations, we propose some key design issues for future studies in this research area.展开更多
Abstract:Ubiquitous broadband Internet access is one of the major goals of the next generation of wireless communications.However,there are still some locations where this is diffcult to achieve.This is the case on mo...Abstract:Ubiquitous broadband Internet access is one of the major goals of the next generation of wireless communications.However,there are still some locations where this is diffcult to achieve.This is the case on moving vehicles and,particularly,on trains.Among the possible solutions to this problem,RoF(Radio-over-Fiber)architectures have been proposed as low-latency,cost-e ective candidates.Two elements are introduced to extend the RoF approach.First,the carrier frequency is raised into the W-band(75-110 GHz)to increase the available capacity.Second,a mechanical beam-steering solution based on a Stewart platform is adopted for the transmitter antenna to allow it to follow a moving receiver along a known path,thereby enhancing the coverage area.The performance of a system transmitting a 2.5 Gbit/s non-return-to-zero signal generated by photonic up-conversion over a wireless link is evaluated in terms of real-time BER(Bit Error Rate)measurements.The receiver is situated in di erent positions,and the orientation of the transmitter is changed accordingly.Values below the forward error correction limit for 7%overhead are obtained over a range of 60 cm around a center point situated 2 m away from the transmitter.展开更多
Recently,in the researches on vehicular Internet-of-Things(IoT),platooning have received lots of attentions due to its potential to improve the fuel efficiency and driving experience.Platoon is a group of vehicles tha...Recently,in the researches on vehicular Internet-of-Things(IoT),platooning have received lots of attentions due to its potential to improve the fuel efficiency and driving experience.Platoon is a group of vehicles that act as smart agents,they travel collaboratively by following the leading human-driven vehicle.A vehicle in the platoon utilizes radar and wireless communication to share important information to other vehicles in the same platoon such as speed and acceleration,to realize the safe and efficient driving.The quality of wireless communication is of great importance to manage and maintain the platoons.However,in a scenario that a large number of vehicles exist,communication delay and packet loss caused by channel congestion may endanger the safe intervehicle distance.In this paper,we introduce intervehicle communication with directional antenna into platooning.By extensive simulations,we evaluate the packet delay and inter-vehicle distance in both normal driving and braking scenarios,and verify the usefulness of directional antenna in platooning for vehicular IoT.展开更多
Avehicular ad hoc network （VANET） is a packet-switched network, consisting of mobile communication nodes mounted on vehicles, with very limited or no infrastructure support [1]. It supports communications among near...Avehicular ad hoc network （VANET） is a packet-switched network, consisting of mobile communication nodes mounted on vehicles, with very limited or no infrastructure support [1]. It supports communications among nearby vehicles,展开更多
车载网VANET是一种应用于智能交通系统的新型无线移动自组织网络(mobile ad hoc network,MANET).随着车辆以及移动ad hoc网络技术的发展,车载网已经成为一个新兴的研究领域.针对VANET中车辆行驶的特征,提出一种拓扑相对稳定的车辆分簇算...车载网VANET是一种应用于智能交通系统的新型无线移动自组织网络(mobile ad hoc network,MANET).随着车辆以及移动ad hoc网络技术的发展,车载网已经成为一个新兴的研究领域.针对VANET中车辆行驶的特征,提出一种拓扑相对稳定的车辆分簇算法.在此算法基础上,根据专用短程通信(dedicated short range communication,DSRC)标准中控制信道(control channel,CCH)和服务信道(service channel,SCH)的分配,考虑车辆间的无线通信干扰和不同应用的QoS需求,提出一种基于分簇的多信道混合型MAC协议,簇内通信采用非竞争的TDMA机制,簇间通信采用基于竞争的CSMA?CA机制,相邻簇采用不同的服务信道.模拟实验表明,提出的MAC协议在同时满足实时应用的延迟需求和非实时应用的吞吐量方面,优于现有协议.展开更多
Autonomous driving is an emerging technology attracting interests from various sectors in recent years.Most of existing work treats autonomous vehicles as isolated individuals and has focused on developing separate in...Autonomous driving is an emerging technology attracting interests from various sectors in recent years.Most of existing work treats autonomous vehicles as isolated individuals and has focused on developing separate intelligent modules.In this paper,we attempt to exploit the connectivity among vehicles and propose a systematic framework to develop autonomous driving techniques.We first introduce a general hierarchical information fusion framework for cooperative sensing to obtain global situational awareness for vehicles.Following this,a cooperative intelligence framework is proposed for autonomous driving systems.This general framework can guide the development of data collection,sharing and processing strategies to realize different intelligent functions in autonomous driving.展开更多
Vehicular communications and networking can improve road safety, faeilitate intelligenl transporlation, support infotainment, dala sharing, and location based serviees, and will be a eritical component in the Internet...Vehicular communications and networking can improve road safety, faeilitate intelligenl transporlation, support infotainment, dala sharing, and location based serviees, and will be a eritical component in the Internet of Things. This special issue aims to present the state of the art in research and development of vehicular communication technology and its potential applications. We are soliciting original contribulions. The topics of interest include, but arc not limited to：展开更多
基金supported by Shandong Agricultural University Funding of First-class DisciplinesShandong Agricultural University Key Cultivation Discipline Funding for NSFC Proposers+1 种基金supported by Grant of Beihang University Beidou Technology Transformation and Industrialization (BARI1709)Open Project of National Engineering Research Center for Information Technology in Agriculture (No.KF2015W003)
文摘This paper derives a non-stationary multiple-input multiple-output(MIMO) from the one-ring scattering model. The proposed channel model characterizes vehicular radio propagation channels with considerations of moving base and mobile stations, which makes the angle of arrivals(AOAs) along with the angle of departures(AODs) time-variant. We introduce the methodology of including the time-variant impacts when characterizing non-stationary radio propagation channels through the geometrical channel modelling approach. We analyze the statistical properties of the proposed channel model including the local time-variant autocorrelation function(ACF) and the space cross-correlation functions(CCFs). We show that the model developed in this paper for non-stationary scenarios includes the existing one-ring wide-sense stationary channel model as its special case.
基金supported by the Chinese Postdoctoral Science Foundation No. 2015M570937the Open Research Fund of National Mobile Communications Research Laboratory,Southeast University No. 2014D03+2 种基金the National High-Tech R&D Program(863 Program) No.2015AA010301the National Natural Science Foundation of Chinaunder Grant No.61572072the Fundamental Research Funds for the Central Universities "Research on the System of Personalized Education using Big Data"
文摘This paper investigates the resource scheduling for heterogeneous vehicular networks, where some moving vehicles are selected and scheduled as helping relays to assist information transmission between the roadside infrastructure and other moving vehicles. For such a system, we propose a mobile-service based max-min fairness resource scheduling scheme, where service amount which is more suitable for high mobility scenarios is adopted to characterize the information transmission capacity of the links and the max-min criteria is adopted to meet the fairness requirement of the moving vehicles. Simulation results demonstrate the effectiveness of our proposed scheme. It is shown that our proposed scheme archives higher throughput and better fairness compared with random scheduling scheme and non-relaying scheme.
基金supported in part by the National Key R&D Program of China under Grant 2018YFB2202202in part by Fundamental Research Funds for the Central Universities under Grants 21620351.
文摘Vehicle-to-vehicle(V2V)communication appeals to increasing research interest as a result of its applications to provide safety information as well as infotainment services.The increasing demand of transmit rates and various requirements of quality of services(QoS)in vehicular communication scenarios call for the integration of V2V communication systems and potential techniques in the future wireless communications,such as full duplex(FD)and non-orthogonal multiple access(NOMA)which enhance spectral efficiency and provide massive connectivity.However,the large amount of data transmission and user connectivity give rise to the concern of security issues and personal privacy.In order to analyze the security performance of V2V communications,we introduce a cooperative NOMA V2V system model with an FD relay.This paper focuses on the security performance of the FD-NOMA based V2V system on the physical layer perspective.We first derive several analytical results of the ergodic secrecy capacity.Then,we propose a secrecy sum rate optimization scheme utilizing the instantaneous channel state information(CSI),which is formulated as a non-convex optimization problem.Based on the differential structure of the non-convex constraints,the original problem is approximated and solved by a series of convex optimization problems.Simulation results validate the analytical results and the effectiveness of the secrecy sum rate optimization algorithm.
基金supported by the Beijing University of Posts and Telecommunications project No.500418759the State Key Laboratory of Networking and Switching Technology project No.600118124
文摘Vehicular Ad-hoc Networks(VANETs) require reliable data dissemination for time-sensitive public safety applications. An efficient routing protocol plays a vital role to achieve satisfactory network performance. It is well known that routing is a challenging problem in VANETs due to the fast-changing network typology caused by high mobility at both ends of transmission. Moreover, under urban environment, there are two non-negligible factors in routing protocol design, the non-uniform vehicle distribution caused by traffic lights, and the network congestion due to high traffic demand in rush hours. In this paper, we propose a greedy traffic light and queue aware routing protocol(GTLQR) which jointly considers the street connectivity, channel quality, relative distance, and queuing delay to alleviate the packet loss caused by vehicle clustering at the intersection and balance the traffic load among vehicles. Through performance evaluation, we show that our proposed protocol outperforms both TLRC and GLSR-L in terms of packet delivery ratio and end-to-end delay.
文摘车载移动通信中信噪比与Doppler频移对通信质量有重要影响.本文探究了基于迭代自相关函数的Doppler频移估计算法,指出其在高车速环境下估计误差较大,提出了一种插值改进方法以改善高车速时的Doppler频移估计.最后根据迭代Doppler频移估计在不同迭代环节具有不同估计误差这一特性,提出了基于Doppler频移估计误差比的信噪比估计算法.计算机仿真结果表明,所提出的算法在一般通信系统的工作信噪比与车速范围内均有较好的估计性能,最高仿真车速达到了300 km/h.
基金supported by the Key Technology Research Project of Jiangxi Province(20213AAE01007)National Natural Science Foundation of China(61871047,61901047)the Proof-of-concept project of Zhongguancun Open Laboratory under Grant(202103001)。
文摘When there is an increasing interest in visible light communication(VLC), outdoor vehicle VLC has emerged as a promising candidate technology for future intelligent transportation systems. However, in VLC based vehicular applications, several challenges impede successful commercial application of VLC based products. This article first provides a thorough overview of the existing challenges. To overcome these challenges, we propose a novel architecture with tracking and environment sensing ability for practical vehicular applications. Moreover, a proof-ofconcept prototype is implemented to validate the feasibility of the proposed system. Experimental and simulation results show that the proposed VLC system can provide reliable communications with a bit-error rate less than 10-4for vehicles under strong interference lights. Finally, based on the evaluations, we propose some key design issues for future studies in this research area.
基金This work is supported by the Marie Sk lodowska-Curie Innovative Training Network CELTA supported by the European Union's Horizon 2020 research and innovation programme(No.675683)the Innovative Training Network FiWiN5G project founded by the European Union's Horizon 2020 research and innovation programme(No.642355).
文摘Abstract:Ubiquitous broadband Internet access is one of the major goals of the next generation of wireless communications.However,there are still some locations where this is diffcult to achieve.This is the case on moving vehicles and,particularly,on trains.Among the possible solutions to this problem,RoF(Radio-over-Fiber)architectures have been proposed as low-latency,cost-e ective candidates.Two elements are introduced to extend the RoF approach.First,the carrier frequency is raised into the W-band(75-110 GHz)to increase the available capacity.Second,a mechanical beam-steering solution based on a Stewart platform is adopted for the transmitter antenna to allow it to follow a moving receiver along a known path,thereby enhancing the coverage area.The performance of a system transmitting a 2.5 Gbit/s non-return-to-zero signal generated by photonic up-conversion over a wireless link is evaluated in terms of real-time BER(Bit Error Rate)measurements.The receiver is situated in di erent positions,and the orientation of the transmitter is changed accordingly.Values below the forward error correction limit for 7%overhead are obtained over a range of 60 cm around a center point situated 2 m away from the transmitter.
基金This research was supported by Grant-in-Aid for Scientific Research(C)(20K11764)the Telecommunications Advancement Foundation and ROIS NII Open Collaborative Research 21FA01.
文摘Recently,in the researches on vehicular Internet-of-Things(IoT),platooning have received lots of attentions due to its potential to improve the fuel efficiency and driving experience.Platoon is a group of vehicles that act as smart agents,they travel collaboratively by following the leading human-driven vehicle.A vehicle in the platoon utilizes radar and wireless communication to share important information to other vehicles in the same platoon such as speed and acceleration,to realize the safe and efficient driving.The quality of wireless communication is of great importance to manage and maintain the platoons.However,in a scenario that a large number of vehicles exist,communication delay and packet loss caused by channel congestion may endanger the safe intervehicle distance.In this paper,we introduce intervehicle communication with directional antenna into platooning.By extensive simulations,we evaluate the packet delay and inter-vehicle distance in both normal driving and braking scenarios,and verify the usefulness of directional antenna in platooning for vehicular IoT.
文摘Avehicular ad hoc network （VANET） is a packet-switched network, consisting of mobile communication nodes mounted on vehicles, with very limited or no infrastructure support [1]. It supports communications among nearby vehicles,
文摘车载网VANET是一种应用于智能交通系统的新型无线移动自组织网络(mobile ad hoc network,MANET).随着车辆以及移动ad hoc网络技术的发展,车载网已经成为一个新兴的研究领域.针对VANET中车辆行驶的特征,提出一种拓扑相对稳定的车辆分簇算法.在此算法基础上,根据专用短程通信(dedicated short range communication,DSRC)标准中控制信道(control channel,CCH)和服务信道(service channel,SCH)的分配,考虑车辆间的无线通信干扰和不同应用的QoS需求,提出一种基于分簇的多信道混合型MAC协议,簇内通信采用非竞争的TDMA机制,簇间通信采用基于竞争的CSMA?CA机制,相邻簇采用不同的服务信道.模拟实验表明,提出的MAC协议在同时满足实时应用的延迟需求和非实时应用的吞吐量方面,优于现有协议.
基金in part supported by the Ministry National Key Research and Development Project under Grant 2017YFE0121400the Major Project from Beijing Municipal Science and Technology Commission under Grant Z181100003218007the National Natural Science Foundation of China under Grants 61622101 and 61571020
文摘Autonomous driving is an emerging technology attracting interests from various sectors in recent years.Most of existing work treats autonomous vehicles as isolated individuals and has focused on developing separate intelligent modules.In this paper,we attempt to exploit the connectivity among vehicles and propose a systematic framework to develop autonomous driving techniques.We first introduce a general hierarchical information fusion framework for cooperative sensing to obtain global situational awareness for vehicles.Following this,a cooperative intelligence framework is proposed for autonomous driving systems.This general framework can guide the development of data collection,sharing and processing strategies to realize different intelligent functions in autonomous driving.
文摘Vehicular communications and networking can improve road safety, faeilitate intelligenl transporlation, support infotainment, dala sharing, and location based serviees, and will be a eritical component in the Internet of Things. This special issue aims to present the state of the art in research and development of vehicular communication technology and its potential applications. We are soliciting original contribulions. The topics of interest include, but arc not limited to：
