AN-aided Secure Beamforming Design for Dual-Functional Radar-Communication Systems

Dual-functional radar-communication (DFRC) systems can utilize the same hardware platforms and spectrum resources to simultaneously realize radar sensing and communication functionalities. This paper focuses on the secure beamforming design for multi-input multi-output (MIMO) DFRC systems, in which the target of interest is considered as a vicious eavesdropper who attempts to eavesdrop the information transmissions from the DFRC base station (BS) to the multiple legitimate users. In order to ensure the confidential information transmissions, artificial noise (AN) is generated at the BS to disrupt the receptions of the eavesdropper. While satisfying the communication quality-of-service (QoS) requirements of the legitimate users, the constant-modulus power constraints, and the beampattern similarity constraint, the maximum eavesdropping signal-to-interference-plus-noise ratio (SINR) of the target is minimized by jointly optimizing the transmit beamforming and the AN. A semi-definite relaxation (SDR) and fractional programming (FP) based algorithm is proposed to solve for the non-convex AN-aided secure beamforming design. Simulation results verify the effectiveness of the proposed scheme and associated beamforming design algorithm in ensuring the secure transmissions for the DFRC systems.