On the Performance of MIMO Cooperative Transmission for Broadband Vehicular Networks

In this paper, we investigate the performance of a cooperative vehicular network over a doubly selective fading channel using multiple antennas at source and destination vehicles. Under the assumption of amplify-and-forward (AF) relaying with orthogonal cooperation protocol and Alamouti-type space-time block coding (STBC), we derive a pairwise error probability (PEP) expression and demonstrate the achievable diversity gains. Our results demonstrate that, via proper linear constellation precoding and digital phase sweeping (DPS), the cooperative vehicular scheme is able to extract the maximum available diversity in frequency (through multipath diversity), time (through Doppler diversity), and spatial (through antenna and cooperative diversity) dimensions. We further conduct Monte Carlo simulations to confirm the analytical derivations and present the error rate performance of the vehicular scheme under various mobility conditions and scenarios.