Analysis of multipath fading due to two-ray fading and vertical fluctuation of the vehicles in ITS inter-vehicle communications

In this paper, we analyze the propagation characteristics of millimeter wave between two vehicles for inter-vehicle communication systems in intelligent transport systems (ITS). Generally, the millimeter wave propagation characteristics between vehicles applied to a two-ray model that consists of a direct wave and a reflected wave from a pavement surface. However, a two-ray model cannot describe the propagation characteristics between the two running vehicles, because the fluctuation of antenna´s height has a strong influence on the received power. Therefore, we need to consider the behavior of the vehicle. We assume that the vehicle is equipped with both front and rear suspensions and that the vertical fluctuation of the vehicle is an approximated one degree of freedom damped oscillation. We investigate the propagation characteristics in inter-vehicle communications by computer simulation.