  In this work, we present a framework analysis of millimeter waves (mmWaves)
vehicular communications systems. Communications between vehicles take place
through a cooperative relay which acts as an intermediary base station (BS).
The relay is equipped with multiple transmit and receive antennas and it
employs decode-and-forward (DF) to process the signal. Also, the relay applies
maximal ratio combining (MRC), and maximal ratio transmission (MRT),
respectively, to receive and forward the signal. As the vehicles' speeds are
relatively high, the channel experiences a fast fading and this time variation
is modeled following the Jakes' autocorrelation model. We also assume
narrowband fading channel. Closed-form expressions of the reliability metrics
such as the outage probability, the probability of error and the channel
capacity are derived. Capitalizing on these performances, we derive the low and
high power regimes for the capacity, and the high
signal-to-interference-plus-noise-ratio (SINR) asymptotes for the outage and
error probability to get full insights into the system gains such as the
diversity and coding gains.
