Non-Stationary Narrowband MIMO Inter-Vehicle Channel Characterization in the 5-GHz Band

In this paper, we describe measurements and models of 30 × 30 narrowband multiple-input-multiple-output (MIMO) vehicle-to-vehicle (V2V) radio propagation channels at 5.3 GHz. Four environments were considered: a campus, a highway, a suburban area, and an urban area. Since the scattering environment may rapidly change in V2V communications, we first investigate the validity of the wide-sense stationarity (WSS) assumption for such channels using the correlation matrix distance (CMD), which is a metric for the characterization of the MIMO channel nonstationarity. Moreover, statistical channel models were developed for these environments, which take into account the non-stationary behavior of the measured V2V channels. The large-scale fading was found to be lognormally distributed, whereas the small-scale fading was characterized by the flexible Weibull distribution. Finally, the non-stationary behavior of both large-scale fading and small-scale fading statistics was investigated.