Design of ISAC Directional Modulation Exploring Reconfigurable Intelligent Surface

Directional modulation (DM) is a promising physical layer security technology gaining attention in both academia and industry. This paper presents a design approach for integrated sensing and communication (ISAC) systems using reconfigurable intelligent surfaces (RIS). The method aims to enhance radar target estimation by maximizing the signal-to-noise ratio (SNR) in the radar direction while maintaining the communication constellation. Additionally, it introduces a mismatch threshold to disrupt unintended signal directions, with the RIS optimizing discrete phase values to improve overall communication and radar performance.