Transmit Antenna Selection in Vehicle-to-Vehicle Time-Varying Fading Channels

Transmit antenna selection (TAS) schemes have been adopted in various communication systems to provide improved performance with relatively reduced complexity. The quality-of-service (QoS) in these systems depends on the availability of perfect channel state information (CSI). In practice, it is difficult to acquire perfect CSI, since it may get outdated due to feedback process. In this paper, we investigate the impact of outdated CSI in a TAS system that operates in a vehicle-to-vehicle (V2V) communication environment. The V2V channel is modeled by the double-Weibull (DW) distribution, a widely adopted distribution for modelling scenarios where both the transmitter and the receiver are in motion. In this context, we introduce and derive important statistical metrics for the bivariate DW distribution, such as the probability density function, the cumulative distribution function, and the moments. Based on them, exact expressions for the outage probability and the average bit error probability of the TAS scheme are derived under the assumption of outdated CSI. Moreover, simplified asymptotic closed-form expressions have been obtained. These expressions are then used to study the performance of the system under consideration.