| Vehicle-to-vehicle (V2V) communication research has been growing steadily over the past decade. The V2V channel differs significantly from classic cellular wireless channels specifically in its relatively low transmitter (Tx) and receiver (Rx) antenna heights, and that both Tx and Rx and some significant scatterers are all mobile. Given the dynamic nature of the V2V environment, the channel may be statistically non-stationary (NS), and traditional wide-sense stationary uncorrelated scattering (WSSUS) channel models will only be applicable for short durations. In this dissertation, we propose and evaluate NS V2V channel models in the 5 GHz band. We present TDL models for additional values of channel bandwidth. Together with the previously reported results for 5 MHz and 10 MHz channel bandwidths, they comprise a set of V2V TDL models for a wide range (from 1 MHz to 50 MHz) of channel bandwidths. New Small City measurements were conducted in two small cities with antennas inside the cars. The results were discussed and compared to previously measured Small City data. We also improve our Markov modeling of multipath persistence processes via the development of higher order homogeneous, 1st-order non-homogeneous and correlated 1st-order homogenous discrete time Markov chain (DTMC) models for persistence. Based upon the trade-off between model fidelity and implementation complexity, the 2 nd-order homogeneous DTMC model is preferable, and the correlated DTMC models may be useful when highest model fidelity is needed. Empirical two-tap approximation of V2V channels is also discussed. With parameters directly derived from the measured delay spread statistics, the two-tap models yield RMS-DS distributions that agree well with the measured data. Further evaluation of the two-tap models on the BER performance for BPSK indicates a good match of the simulation results between the two-tap and the complete models, especially for low SNR's. Thus our simple two-tap model could be useful as an informative alternative to the complete NS models. The GBS model is another common type of V2V channel model. An example V2V geometry model is developed and compared to our TDL model both qualitatively and quantitatively. |
