Throughput Analysis of Vehicle-Centric Cooperative Transmission in Ultra-Dense V2I Networks

With the rapid development of 5G wireless communication system, more and more vehicular applications in intelligent transportation system (ITS) are supposed to be supported by 5G vehicle-to-everything (V2X) communications. Due to the requirement of higher transmission rate and the tendency of denser deployment of roadside infrastructure, the ultra-dense network (UDN) is proposed to enhance the throughput performance of 5G vehicle-to-infrastructure (V2I) networks. In order to relieve the interference resulting from the densification of V2I networks, we introduce a vehicle-centric cooperative transmission scheme and a distance-based resource reuse mechanism. The former takes the vehicle at the center and associates it with several cooperative road side units (RSUs), so as to eliminate the cell edge effect in conventional cell-centric network and avoid intra-cell interference. The latter restricts the resource reuse distance between vehicles in order to mitigate inter-cell interference. In this paper, we provide an analytical 1-D system model, and derive the exact tractable expressions of the two throughput metrics based on stochastic geometry. Moreover, analytical results are validated by Monte Carlo simulations. Additionally, our numerical results reveal the relationship between the two throughput metrics and the major performance-impacting parameters, which has a certain guidance for designing ultra-dense V2I networks.