The convergence of sensing and communication, termed integrated sensing and communication (ISAC), is a cornerstone technology for next-generation autonomous vehicular networks. However, the performance of these systems is frequently constrained by harsh propagation environments featuring blockages. Reconfigurable intelligent surface (RIS) has emerged as a potent technique for intelligently tailoring the propagation environment, thereby yielding significant benefits for vehicular ISAC. This paper proposes a novel beamforming scheme integrating passive beamforming at RIS and active beamforming at vehicular ends. Efficient solutions to the formulated optimization problem are subsequently derived via alternating optimization (AO) and semidefinite relaxation (SDR) methods. Two practical criteria are employed for solving the optimization problem: one is fairness-oriented, i.e., ensuring uniform coverage, denoted as Max-Min-SNR; the other focuses on maximizing total information, termed Max-SIR. Simulation results show that, compared with existing baseline schemes, the Max-Min-SNR-based beamforming scheme attains a 7.66 dB (5.8-fold) enhancement in the minimum sensing SNR, while the Max-SIR-based scheme delivers a 45% information rate gain—thus verifying the superiority of the proposed beamforming scheme.

The demanding objectives for the future sixth generation (6G) of wireless communication networks have spurred recent research efforts on novel materials and radio-frequency front-end architectures for wireless connectivity, as well as revolutionary communication and computing paradigms. Among the pioneering candidate technologies for 6G belong the reconfigurable intelligent surfaces (RISs), which are artificial planar structures with integrated electronic circuits that can be programmed to manipulate the incoming electromagnetic field in a wide variety of functionalities. Incorporating RISs in wireless networks have been recently advocated as a revolutionary means to transform any wireless signal propagation environment to a dynamically programmable one, intended for various networking objectives, such as coverage extension and capacity boosting, spatiotemporal focusing with benefits in energy efficiency and secrecy, and low electromagnetic field exposure. Motivated by the recent increasing interests in the field of RISs and the consequent pioneering concept of the RIS-enabled smart wireless environments, in this paper, we overview and taxonomize the latest advances in RIS hardware architectures as well as the most recent developments in the modeling of RIS unit elements and RIS-empowered wireless signal propagation. We also present a thorough overview of the channel estimation approaches for RIS-empowered communications systems, which constitute a prerequisite step for the optimized incorporation of RISs in future wireless networks. Finally, we discuss the relevance of the RIS technology in the latest wireless communication standards, and highlight the current and future standardization activities for the RIS technology and the consequent RIS-empowered wireless networking approaches.