On the performance of cooperative vehicular networks under antenna correlation at RSU

Abstract

Vehicular communications is gradually becoming mature after decades of exciting developments and thriving advances. Resultantly, these advances have opened new possibilities for vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications to meet the requirements of safety applications and future self-driving technologies. While performance limits of single link vehicular communications have been well analyzed in the literature, only incremental growth has been shown in the domain of multi-antenna communications. Another major concern is that the existing works mostly assume independent fading at the antennas mounted on road side unit (RSU), thus neglecting the impact of channel correlation. Our work addresses this issue by evaluating packet error probability for two renowned antenna correlation models i.e., constant correlation (CC) and exponential correlation (EC), under Nakagami-m fading. We also consider cooperation between intermediate vehicles to ensure reliable communication from the source vehicle to the RSU. More specifically, we derive closed-form expressions of packet error probability for three cooperative techniques, namely, single helper selection (SHS), multi-hop cooperative selection (MCS) and multiple helper selection (MHS). We quantify the performance variations for different numbers of intermediate helper vehicles, and for varying values of fading parameter and correlation coefficients. Finally, we validate our mathematical derivations by performing extensive simulations in MATLAB.