Demystifying millimeter-wave V2X: towards robust and efficient directional connectivity under high mobility
Demystifying millimeter-wave V2X: towards robust and efficient directional connectivity under high mobility
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DOI：
10.1145/3372224.3419208
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发表时间：
2020-09
期刊：
影响因子：
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通讯作者：
Song Wang;Jingqi Huang;Xinyu Zhang
中科院分区：
文献类型：
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作者：
Song Wang;Jingqi Huang;Xinyu Zhang
毫米波（mmWave）网络是满足新兴互联汽车苛刻带宽需求的核心技术。然而，毫米波车对一切（V2X）连接的可行性一直受到质疑。一个主要的疑问在于高度定向的毫米波链路如何在高移动性下维持。在本文中，我们提出了毫米波V2X网络的第一个全面的现实检查。我们部署了一个实验测试平台来模拟典型的毫米波V2X场景，并定制了一个COTS毫米波无线电，以便对信道和链路进行微观研究。我们进一步构建了一个高保真的3D射线追踪器，以大规模再现毫米波特性。利用该工具集，我们研究了毫米波V2X覆盖、移动性和阻塞、码本/波束管理和空间复用。我们的测量揭穿了对毫米波V2X网络的一些常见误解。特别是，由于巷道网络结构的限制，我们发现只要设计适当的码本，波束管理可以很容易地通过经常被指责的波束扫描方案来处理。通过适当的基站部署和合作，几乎可以消除阻塞。即使没有复杂的MIMO无线电，也可以实现高效的空间复用。我们的工作指出了在高移动性下实现高效可靠的毫米波网络的可能方法，同时保持标准网络协议的简单性。
Millimeter-wave (mmWave) networking represents a core technology to meet the demanding bandwidth requirements of emerging connected vehicles. However, the feasibility of mmWave vehicle-to-everything (V2X) connectivity has long been questioned. One major doubt lies in how the highly directional mmWave links can sustain under high mobility. In this paper, we present the first comprehensive reality check of mmWave V2X networks. We deploy an experimental testbed to mimic a typical mmWave V2X scenario, and customize a COTS mmWave radio to enable microscopic investigation of the channel and the link. We further construct a high-fidelity 3D ray-tracer to reproduce the mmWave characteristics at scale. With this toolset, we study the mmWave V2X coverage, mobility and blockage, codebook/beam management, and spatial multiplexing. Our measurement debunks some common misperceptions of mmWave V2X networks. In particular, due to the constrained roadway network structures, we find the beam management can be handled easily by the often-denounced beam scanning schemes, as long as the codebook is properly designed. Blockage can be almost eliminated through proper basestation deployment and cooperation. Highly effective spatial multiplexing can be realized even without sophisticated MIMO radios. Our work points to possible ways to realize efficient and reliable mmWave networks under high mobility, while maintaining the simplicity of standard network protocols.