Improved 5.9GHz V2V Short Range Path Loss Model

Abstract

Modeling large-scale fading effects in Vehicle-to-Vehicle communications (V2V) in the 5.9GHz Dedicated Short Range Communication band has received broad coverage in the literature over the last 15 years. The majority of V2V channel measurement campaigns have focused on describing the expected path loss of the V2V channel through empirical models. The path loss is a channel metric which describes how fast the received signal strength decays with distance. It is well known that the path loss exponent and reference path loss (y-intercept) varies for different environments, but it is not well understood how the channel changes in a given environment relative to lane separation or vehicle orientation. This paper presents an improved path loss model for line-of-sight (LOS) V2V communications at distances less than 100m. The path loss model removes the Gaussian random variable component, typically used to model shadowing in classic power law path loss model, and instead makes the y-intercept and path loss exponent Gaussian random variables. Derived from extensive empirical measurement campaigns in which vehicle orientation, approach direction, and lane separation are considered, the new channel model is compared to experimental data in which the vehicles move at different speeds. The improved path loss model performs a better fit to experimental data than existing path loss models, including two-ray ground reflection, dual-slope piecewise linear, and classic power law.