Artificial Noise Aided Directional Modulation with Multilog Frequency Diverse Array

ABSTRACT Directional modulation (DM) has been widely studied as a promising technique for enhancing physical layer security (PLS). In particular, DM combined with frequency diverse arrays (FDA) enables directional transmission on the two‐dimensional plane. However, the inevitable presence of sidelobes in FDA patterns still poses a risk of information leakage to eavesdroppers. To address this limitation, we propose an artificial‐noise‐aided DM scheme based on a multilog frequency diverse array (AN‐DM‐MFDA). Unlike conventiona methods that uniformly transmit artificial noise (AN), the proposed scheme strategically allocates AN to the leakage sidelobes, thereby reducing their vulnerability to interception. Furthermore, we derive the theoretical expressions for the average bit error rate (BER) and the secrecy capacity of the developed system. Simulation results confirm that the proposed scheme achieves stronger secrecy protection while maintaining reliable detection performance for the legitimate user, outperforming existing AN‐aided DM approaches.