V2X(vehicle to everything)通信是车联网中实现环境感知、信息交互与协同控制的重要关键技术。大唐电信科技产业集团最早提出并由中国企业主导的LTE-V2X国际标准作为其中的主流技术之一,能够在高速移动环境中提供低时延、高可靠、高速...V2X(vehicle to everything)通信是车联网中实现环境感知、信息交互与协同控制的重要关键技术。大唐电信科技产业集团最早提出并由中国企业主导的LTE-V2X国际标准作为其中的主流技术之一,能够在高速移动环境中提供低时延、高可靠、高速率、安全的通信能力,并能够最大程度利用TD-LTE已部署网络及终端芯片平台等资源。首先介绍了LTE-V2X的关键技术,并与IEEE 802.11p进行了比较;进而介绍了LTE-V2X的标准研究及其演进以及相关的产业发展和示范应用;最后展望了LTE-V2X的发展策略及其向5G NR-V2X的技术演进等,并提出了相关政策建议。展开更多
Recent advances in wireless communication technologies and auto-mobile industry have triggered a significant research interest in the field of vehicular ad-hoc networks （VANETs） over the past few years. A vehicular ...Recent advances in wireless communication technologies and auto-mobile industry have triggered a significant research interest in the field of vehicular ad-hoc networks （VANETs） over the past few years. A vehicular network consists of vehicle-to-vehicle （V2V） and vehicle-to-infrastructure （V2I） communications supported by wireless access technologies such as IEEE 802.11p. This innovation in wireless communication has been envisaged to improve road safety and motor traffic efficiency in near future through the development of intelligent transportation system （ITS）. Hence, governments, auto-mobile industries and academia are heavily partnering through several ongoing research projects to establish standards for VANETs. The typical set of VANET application areas, such as vehicle collision warning and traffic information dissemination have made VANET an interesting field of mobile wireless communication. This paper provides an overview on current research state, challenges, potentials of VANETs as well as the ways forward to achieving the long awaited ITS.展开更多
IEEE 802.11p/DSRC （Dedicated Short Range Communication） is considered to be a promising wireless communication standard for enhancing transportation safety and efficiency. However, IEEE 802.11p-based Vehicle- to-Veh...IEEE 802.11p/DSRC （Dedicated Short Range Communication） is considered to be a promising wireless communication standard for enhancing transportation safety and efficiency. However, IEEE 802.11p-based Vehicle- to-Vehicle （V2V） communication is still unreliable because of the complicating factors of high vehicle speed and complex radio environments. In this paper, we performed a data-based evaluation of V2V communication reliability, using real-world measurements in a typical urban expressway in Beijing. With respect to the characteristics of the urban expressway and our experimental data, we found road slope and traffic density to be the major environmental factors having a significant impact on the V2V communication＇s Line-Of-Sight （LOS） conditions. On the basis of these two factors, we propose a fuzzy classification method for the LOS conditions, and separate the real- time communication environments into different LOS cases. For each LOS case, we quantify the metrics as received signal strength indication, packet delivery rate, and communication latency. The results reveal that the communication reliability in urban expressways is very unstable because of the changing LOS conditions. This study provides a useful reference for the IEEE 802.11 p-based cooperative systems in urban expressways.展开更多
车到车(vehicle to vehicle,V2V)通信因其复杂恶劣的信道环境,对系统的信道估计性能提出了更高的要求.针对IEEE 802.11p协议中导频过少无法准确跟踪频率选择性衰落信道的问题,提出了一种基于交错导频辅助的信道估计与跟踪方法.该方法将...车到车(vehicle to vehicle,V2V)通信因其复杂恶劣的信道环境,对系统的信道估计性能提出了更高的要求.针对IEEE 802.11p协议中导频过少无法准确跟踪频率选择性衰落信道的问题,提出了一种基于交错导频辅助的信道估计与跟踪方法.该方法将相邻符号的导频交错排布,利用相邻符号间信道的高度相关性,对前后时刻导频位置的信道估计结果进行插值运算,对V2V信道进行实时跟踪,在不改变IEEE 802.11p数据传输效率的前提下,其误码率性能在空旷高速的通信场景下明显优于基于原导频辅助的信道估计与跟踪方法.在所提出的交错导频框架下,针对不同V2V通信场景的特点选择合适的信道估计方案,可以较大程度地提高IEEE 802.11p的系统性能.展开更多
文摘V2X(vehicle to everything)通信是车联网中实现环境感知、信息交互与协同控制的重要关键技术。大唐电信科技产业集团最早提出并由中国企业主导的LTE-V2X国际标准作为其中的主流技术之一,能够在高速移动环境中提供低时延、高可靠、高速率、安全的通信能力,并能够最大程度利用TD-LTE已部署网络及终端芯片平台等资源。首先介绍了LTE-V2X的关键技术,并与IEEE 802.11p进行了比较;进而介绍了LTE-V2X的标准研究及其演进以及相关的产业发展和示范应用;最后展望了LTE-V2X的发展策略及其向5G NR-V2X的技术演进等,并提出了相关政策建议。
基金supported by a Grant-in-Aid for Scientific Research from Ebonyi State Government(EBSG)(No.EBSG/SSB/PS/VII/105)
文摘Recent advances in wireless communication technologies and auto-mobile industry have triggered a significant research interest in the field of vehicular ad-hoc networks （VANETs） over the past few years. A vehicular network consists of vehicle-to-vehicle （V2V） and vehicle-to-infrastructure （V2I） communications supported by wireless access technologies such as IEEE 802.11p. This innovation in wireless communication has been envisaged to improve road safety and motor traffic efficiency in near future through the development of intelligent transportation system （ITS）. Hence, governments, auto-mobile industries and academia are heavily partnering through several ongoing research projects to establish standards for VANETs. The typical set of VANET application areas, such as vehicle collision warning and traffic information dissemination have made VANET an interesting field of mobile wireless communication. This paper provides an overview on current research state, challenges, potentials of VANETs as well as the ways forward to achieving the long awaited ITS.
基金partially supported by the National Key Basic Research and Development (973) Program of China (No. 2012CB725405)the National Natural Science Foundation of China (No. 61273238)
文摘IEEE 802.11p/DSRC （Dedicated Short Range Communication） is considered to be a promising wireless communication standard for enhancing transportation safety and efficiency. However, IEEE 802.11p-based Vehicle- to-Vehicle （V2V） communication is still unreliable because of the complicating factors of high vehicle speed and complex radio environments. In this paper, we performed a data-based evaluation of V2V communication reliability, using real-world measurements in a typical urban expressway in Beijing. With respect to the characteristics of the urban expressway and our experimental data, we found road slope and traffic density to be the major environmental factors having a significant impact on the V2V communication＇s Line-Of-Sight （LOS） conditions. On the basis of these two factors, we propose a fuzzy classification method for the LOS conditions, and separate the real- time communication environments into different LOS cases. For each LOS case, we quantify the metrics as received signal strength indication, packet delivery rate, and communication latency. The results reveal that the communication reliability in urban expressways is very unstable because of the changing LOS conditions. This study provides a useful reference for the IEEE 802.11 p-based cooperative systems in urban expressways.
文摘IEEE 802.11p协议是针对车载环境应用制定的物理层(physical Layer,PHY)与媒体接入控制层(media ac-cess control,MAC)标准。作为智能交通系统的一部分,该协议能极大增加车辆与外界沟通的通讯能力。通过研究802.11p协议和802.11a协议的异同点,在802.11a的基础上给出了采用DSP(digital signal processor)进行802.11p物理层的OFDM(orthogonal frequency division multiplexing)基带处理的设计与实现方案,并给出了基于经典SC算法的接收端保持同步的DSP处理方法。经过仿真及DSP片上系统验证,测试结果表明,设计达到了预期效果。
