  The emergence of the fifth-generation (5G) New Radio (NR) brings additional
possibilities to vehicle-to-everything (V2X) network with improved quality of
services. In order to obtain accurate channel state information (CSI) in
high-mobility V2X networks, pilot signals and frequent handover between
vehicles and infrastructures are required to establish and maintain the
communication link, which increases the overheads and reduces the communication
throughput. To address this issue, integrated sensing and communications (ISAC)
was employed at the base station (BS) in the vehicle-to-infrastructure (V2I)
network to reduce a certain amount of overheads, thus improve the spectral
efficiency. Nevertheless, the exact amount of overheads reduction remains
unclear, particularly for practical NR based V2X networks. In this paper, we
study a link-level NR based V2I system employing ISAC signaling to facilitate
the communication beam management, where the Extended Kalman filtering (EKF)
algorithm is performed to realize the functions of tracking and predicting the
motion of the vehicle. We provide detailed analysis on the overheads reduction
with the aid of ISAC, and show that up to 43.24% overheads can be reduced under
assigned NR frame structure. In addition, numerical results are provided to
validate the improved performance on the beam tracking and communication
throughput.
