Temporal evolution of channel capacity in vehicular MIMO channels in the 5 GHz band

Reliability in Ricean multiple-input-multiple-output (MIMO) channels is crucial for safety related vehicle-to-vehicle (V2V) applications. Due to the time variability of vehicular communication channel, it is very significant to study the temporal evolution of channel characterization criteria. We present evaluation results of the temporal evolution of the spectral efficiency from channel sounder measurements of vehicle-to-vehicle MIMO radio channels in the 5.2 GHz band. Our results show that MIMO channels with higher spatial correlation lead to lower ergodic capacity and a reduced signal-to-noise ratio-dependent critical data rate. The temporal evolution of the ergodic capacity and critical data rate shows that the channel with the strongest line of sight (LoS) component also has the highest capacity. We also present a detailed analysis of the environmental factors affecting the capacity pattern throughout the measurement run. Dynamic scatterers introduce capacity bursts instantaneously; the trend stays congruent with the theory.