Performance analysis of clustering car-following V2X system with wireless power transfer and massive connections

Abstract

With the rapid growth of vehicles, the vehicular networks meet main challenges such as dynamic, heterogeneous, and large scaled. In addition, the cellular-based vehicular networks must satisfy further strict requirements, including ultralow latency, high reliability, high spectrum efficiency, and massive connections of the next-generation (6G) network. Recently, by exploiting vehicle clustering utilized for reducing the complexity of vehicle-to-everything (V2X) systems, it could ultimately improve road traffic efficiency. In some specific scenarios related to Internet of Things, a group of vehicles can be served effectively in terms of spectrum efficiency when two key techniques are enabled, i.e., nonorthogonal multiple access and cognitive radio (CR) schemes are joint deployed. These techniques certainly benefit to 6G V2X services to reduce specific challenges, such as traffic congestion and massive connections. Different from existing works, we propose wireless power transfer applied to the roadside unit to improve the situation that energy shortening in small devices deployed in V2X communications. In particular, we derive expressions of throughput to exhibit performance of the two grouped vehicles. To further indicate advantages of spectrum efficiency, we compare two schemes of V2X systems with and without CR schemes. The numerical results demonstrate that the non-CR NOMA-V2X scheme outperforms the CR-based NOMA-V2X scheme with fixed power allocation, but the non-CR NOMA-V2X scheme costs higher spectrum resource compared with the counterpart. Besides, by comparing with orthogonal multiple access (OMA)-assisted V2X, NOMA-V2X schemes demonstrate superiority in terms of throughput performance whilst achieving the benefits of both NOMA and CR schemes.