Cooperative, Connected and Automated Mobility (CCAM) is expected to leverage the full potential of wireless communications. With the growing adoption of 5G and its support for Vehicle-to-Everything (V2X) communications, beamformed vehicular communications at millimeter-wave (mmWave) bands are expected to enable the most demanding connected driving applications. Beamformed V2X links present the challenge of beam management in such a fast-changing scenario. This paper goes through the practical limitations of the 5G V2X stack to support successful beamforming procedures. Two beam management strategies are proposed. Both strategies are evaluated in terms of power performance, beam recovery time and channel usage. The results suggest that significant differences apply when the beam is more frequently updated, whereas little improvement is seen by increasing the size of the beamset. Also, the selection of a proper strategy is shown to be important to alleviate the channel from overheads, and substantial differences in required signaling can be seen depending on the beam-tracking approach.

协作、互联和自动化移动 (CCAM) 有望充分利用无线通信的潜力。随着 5G 的日益普及及其对车对万物 (V2X) 通信的支持，毫米波 (mmWave) 频段的波束成形车载通信有望支持最苛刻的联网驾驶应用。Beamformed V2X 链路在这种快速变化的场景中提出了波束管理的挑战。本文详细介绍了 5G V2X 堆栈的实际局限性，以支持成功的波束成形程序。提出了两种光束管理策略。两种策略都根据功率性能、波束恢复时间和信道使用情况进行评估。结果表明，当光束更频繁地更新时，应用会有显着差异，而通过增加光束集的大小几乎没有看到改进。此外，选择适当的策略对于减轻信道的开销很重要，并且根据波束跟踪方法可以看到所需信令的显着差异。