Parking Garage Channel Characteristics at 5 GHz for V2V Applications

We provide results for propagation path loss and root-mean-square delay spread within a parking garage, in the 5 GHz band, aimed at V2V applications. Results for both same-floor, and floor-to-floor propagation are shown for a typical urban parking garage structure. For line-of-sight (LOS) conditions, same-floor propagation path loss is well approximated by a 2-ray model. Same-floor non-LOS path loss shows path loss exponent n-3. Path loss for the floor-to-floor case can be well-modeled by accounting for floor attenuation factors and an additional loss that represents distance of the mobile toward the garage interior, away from the garage´s open sides, i.e., a model that accounts for both vertical and horizontal distance. Mean delay spreads reach nearly 150 ns for the same-floor case, and reduce to ~50 ns for the longest (3-floor) distance floor-to-floor case. Since there have been few results for such environments previously published, our results should prove useful for V2V systems deployed in parking garages.