Empirical determination of channel characteristics for DSRC vehicle-to-vehicle communication

Dedicated Short Range Communication (DSRC) wireless band, allocated by the FCC for vehicular communication, constitutes the basis for one of the first vehicular ad-hoc networks/systems that is likely to be deployed. Therefore, it is important to characterize the physical properties of the DSRC channel.In this work we propose that due to the complexity, unpredictability and wide variety of road environments a statistical parametric model should be used to describe the physical channel behavior, and its parameters should be inferred from empirical data.Based on this methodological approach we construct channel gain models for two different environments: an open space and a typical highway with moderate traffic. To model the distribution of channel gain amplitude we choose the well-known two-parameter Nakagami model and estimate the distance dependency of its parameters from empirical road data. Spatial correlation of the channel strength is also estimated for a few separation distances.The results obtained show that in both environments the Nakagami average power parameter O falls off as the inverse-square of the sender-receiver separation distance up to a crossover distance of about 160m and as the inverse-fourth of the distance thereafter. The Nakagami fading parameter m lies between 1 and 4 for the open area and between 0.5 and 1 for the highway. The spatial correlation coefficients lie between 0.4 and 0.75 for the open environment, but between 0.9 and 1 for the highway. These results provide valuable input to support the design of optimal modulation, coding, diversity and protocol schemes for vehicle-to-vehicle and vehicle-to-infrastructure communication.