US20250266889
2025-08-21
Electricity
H04B7/0695
User equipment (UE) plays a critical role in determining sidelink resources for vehicle wireless communications, utilizing signals like the Sidelink Synchronization Signal (SLSS), Sidelink Channel State Information Reference Signal (SL-CSI-RS), or Sidelink Demodulation Reference Signal (SL-DMRS) for initial beam establishment. Beam refinement can occur between communicating UEs or be handled by one UE alone. A base station, such as a gNB, may dynamically assign resources for a dedicated or shared licensed sidelink carrier, guided by RRC configurations or activation/deactivation protocols.
Vehicular communication services under LTE V2X encompass four types: Vehicle-to-Vehicle (V2V), Vehicle-to-Infrastructure (V2I), Vehicle-to-Network (V2N), and Vehicle-to-Pedestrian (V2P). These services can be facilitated via the PC5 interface for direct UE communication or the Uu interface for broader network interaction. V2X sidelink communication through the PC5 interface allows authorized UEs to communicate directly, even outside E-UTRA coverage. The LTE-Uu interface supports both unicast and MBMS modes for flexible transmission and reception.
Enhanced V2X (eV2X) services require advanced data transmission capabilities to support applications such as raw sensor data sharing and vehicle coordination. The 3GPP has identified 25 use cases with stringent requirements for data rate, latency, reliability, and range, categorized into vehicle platooning, extended sensors, advanced driving, and remote driving. High data rate and long communication range are essential for use cases like sensor sharing and video data transmission for automated driving.
NR V2X supports two resource allocation modes: Mode 1, where the base station schedules sidelink resources, and Mode 2, where the UE autonomously selects resources within configured parameters. Mode 1 facilitates dynamic or pre-configured resource allocation through the Uu interface. In contrast, Mode 2 allows UEs to self-select resources or assist others in selection, with options like NR configured grants for streamlined sidelink transmissions.
Beam management in NR V2X involves challenges such as establishing beam pairs without PRACH support. Solutions include using SLSS, SL-CSI-RS, or SL-DMRS for initial beam establishment and refinement procedures tailored to either single or dual UE involvement. gNB-controlled beam forming can occur at various stages, with options to transmit scheduling DCI to either transmitting or both UEs. Beam refinement strategies include iterative processes at both UE ends to optimize alignment and communication quality.