5 GHZ wireless channel characterization for vehicle to vehicle communications

We provide channel modeling results based upon measurements of the vehicle-to-vehicle (VTV) mobile channel, taken in the 5 GHz frequency band. Our measurements pertain to three types of areas: large cities, open highway areas, and small cities. A spread-spectrum stepped correlator technique was used, with omnidirectional antennas either atop or inside the vehicles. We provide measured and analytical results in the form of power delay profiles and frequency correlation function estimates. Delay spread statistics for these environments, as well as approximate amplitude fading distributions are also provided. The largest values of root-mean-square delay spreads, on the order of 1 microsecond, were obtained in urban areas with dense vehicle traffic, corresponding to coherence bandwidths of as low as 1-2 MHz. Fading amplitude statistics are best fit with a Nakagami-m distribution. Fading channel statistics for an example 10 MHz channel bandwidth are also provided.