An Active RIS-Aided DFRC System for Improved Multi-User Communications

The rapid evolution towards sixth-generation (6G) communications necessitates substantial enhancements in data rates, latency, and spectrum efficiency. Dual-functional radar and communication (DFRC) systems and reconfigurable intelligent surfaces (RIS) are pivotal technologies addressing these challenges. Accordingly, this paper introduces an innovative active RIS-aided DFRC system that transcends the limitations of passive RIS. Active RIS not only adjusts signal phases but also amplifies them, significantly boosting signal strength, coverage, and reliability, while also tackling interference and power constraints. We develop a optimization algorithm that leverages weighted minimum mean square error (WMMSE) and fractional programming techniques to maximize the weighted sum rate (WSR) for communication users while ensuring robust radar detection performance. Extensive simulations validate the superiority of active RIS-assisted DFRC systems over passive configurations, demonstrating substantial improvements in both communication and radar functionalities. Our results highlight the transformative potential of active RIS in revolutionizing 6G networks, enhancing their adaptability, efficiency, and capability to support future applications like autonomous driving and smart city infrastructures. This paper sets a new benchmark for integrating active RIS in DFRC systems, paving the way for advanced 6G technologies.