  The potential of using visible light communication (VLC) technologies for
vehicular communication networks has recently attracted much attention. The
underlying VLC channels, as a foundation for the proper design and optimization
of vehicular VLC communication systems, have not yet been sufficiently
investigated. Vehicular VLC link impairments can have a significant impact on
the system performance and capacity. Such impairments include the optical
wireless channel distortion and background noise. This paper proposes a novel
three-dimensional (3D) regular-shaped geometry-based stochastic model (RS-GBSM)
for vehicular VLC multiple-input single-output (MISO) channels. The proposed 3D
RS-GBSM combines a two-sphere model and an elliptic-cylinder model. Both the
line-of-sight (LoS) and single-bounced (SB) components are considered. The
proposed model jointly considers the azimuth and elevation angles by using
von-Mises-Fisher (VMF) distribution. Based on the proposed model, the
relationship between the communication range and the received optical power is
analyzed and validated by simulations. The impact of the elevation angle in the
3D model on the received optical power is investigated by comparing with the
received optical power of the corresponding two-dimensional (2D) model.
Furthermore, the background noise is also modeled to evaluate the system's
signal-to-noise ratio (SNR).
