RIS-Enabled Self-Interference Elimination in Monostatic Full-Duplex DFRC Systems

A key challenge in Integrated Sensing and Communications (ISAC), especially in Full-Duplex (FD) Dual-Functional Radar-Communication (DFRC) systems, is self-interference (SI) caused by signal leakage from the transmitter to the receiver, impairing sensing tasks. Reconfigurable Intelligent Surface (RIS) can manipulate signal reflections with minimal power, making them promising for enhancing 6G communication, yet its potential for SI mitigation in DFRC systems is underexplored. This paper proposes a novel RIS-enabled approach for SI elimination in mono-static full-duplex DFRC systems. Our method decomposes the RIS function into spatial beam-forming and temporal modulation to ensure sufficient target illumination and orthogonality between reflected and transmitted waveforms, effectively eliminating SI without the need for SI channel information. Simulations confirm the effectiveness of the proposed approach in SI elimination and sensing performance.