Article

A Measurement Based Shadow Fading Model for Vehicle-to-Vehicle Network Simulations

03/2012;
Source: arXiv

ABSTRACT The vehicle-to-vehicle (V2V) propagation channel has significant implications
on the design and performance of novel communication protocols for vehicular ad
hoc networks (VANETs). Extensive research efforts have been made to develop V2V
channel models to be implemented in advanced VANET system simulators for
performance evaluation. The impact of shadowing caused by other vehicles has,
however, largely been neglected in most of the models, as well as in the system
simulations. In this paper we present a simple shadow fading model targeting
system simulations based on real measurements performed in urban and highway
scenarios. The measurement data is separated into three categories,
line-of-sight (LOS), obstructed line-of-sight (OLOS) by vehicles, and non
line-of-sight (NLOS) by buildings, with the help of video information, recorded
during the measurements. It is observed that vehicles obstructing the LOS
induce an additional attenuation of about 10 dB in the received signal power.
We use a Markov chain based state transition diagram to model the transitions
between the LOS, OLOS and NLOS states. Further, sample state transition
intensities based on the measurements and simulated traffic are presented. An
approach to incorporate the LOS/OLOS model into existing VANET simulators is
also provided. Finally, system level VANET simulation results are presented,
which show the difference between the LOS/OLOS model and a channel model based
on Nakagami-m fading.

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