Sense and Jam: ISAC-Aided Robust Physical Layer Security

This work proposes a physical layer security (PLS) framework leveraging integrated sensing and communication (ISAC) to facilitate secure communication. The framework employs a multi-antenna full-duplex (FD), dual-functional access point (AP) to establish a secure communication zone around the intended user. The AP performs target sensing to detect the desired user and simultaneously employs artificial noise (AN) to jam any undesired users within the zone. In the first time slot, the AP sweeps the beam from a discrete Fourier transform-based codebook to sense the environment via its transmit antenna array, while the receive antenna array captures echoes from targets. If undesired users are detected within the secure communication zone, the downlink (DL) signal is augmented with friendly AN to obstruct their overhearing attempts. For the uplink (UL), the same set of transmit antennas beams AN towards the undesired users, while the receive antennas capture the UL signals from the desired user. By combining optimal beam selection, target sensing, and AN transmission, an FD secure communication link is established between the AP and desired user. Simulation results show that the proposed scheme significantly improves DL and UL secrecy rates compared to conventional methods.