Radar-aided reconfigurable intelligent surface for vehicular wireless communication

In the intricate traffic environment of modern cities, challenges like insufficient wireless signal coverage and obstructed propagation links between base stations (BS) and vehicles are prevalent. Meanwhile, reconfigurable intelligent surface (RIS) offers what we believe to be a novel solution relying on its robust real-time control over electromagnetic (EM) waves, providing a new approach to achieving intelligent transportation and vehicle connectivity. In this paper, we propose a radar-aided intelligent wireless communication system for dynamic beam tracking. The system leverages frequency-modulated continuous wave (FMCW) radar to detect the location information of the surrounding vehicles, a pre-trained artificial neural network (ANN) combined with control boards to generate the voltage coding sequence of the desired deflection direction, and the dual-polarized RIS to realize intelligent beam tracking and wireless communication. We design a 3-bit dual-polarized RIS, consisting of 256 (16 × 16) independently controllable units, running at 3.5 GHz, and develop a high-speed control board to ensure real-time refresh of the voltage coding sequence. Comparative experiments are conducted in three different environments. The experiments consistently demonstrate that, with the assistance of the radar, the RIS can achieve dynamic beam tracking without manual intervention. The system can effectively improve wireless signal strength and communication stability, providing a new viable approach for the development of intelligent vehicular networking.