Millimeter wave V2I beam-training using base-station mounted radar

Reducing the beam-training overhead is a major challenge in realizing millimeter wave (mmWave) V2I communication systems. In this work, we use location of the vehicle to reduce the beam-training overhead of line-of-sight V2I links. Specifically, we consider a base-station (BS) supporting an analog mmWave communication system and an off-the-shelf automotive radar. Using Crámer-Rao lower bound on the DoA estimation error of a radar, we establish that an off-the-shelf radar has better localization than global navigation satellite system (GNSS). The spectral efficiency results show that beam-training based on radar based localization is robust to vehicle speeds.