Waveform-beam Joint Suppression Method for Interrupted-Sampling Repeater Jamming

Interrupted-Sampling Repeater Jamming (ISRJ) exploits undersampling and its unique matched filter response to generate multiple coherent false target peaks at the radar receiver, disrupting genuine target detection and tracking. Under low interference-to-signal ratio (ISR) conditions, conventional array radar beamforming anti-jamming techniques often induce target echo “self-cancellation”. To address these limitations, this paper proposes a robust beamforming method against ISRJ based on joint waveform and beam processing. A designed Multi-frequency Sparse Spectral Line Signal (MF-SSLS) waveform leverages the key characteristic that ISRJ generates additional high-energy interference spectral components on both sides of the original sparse spectral peak. The method computes the interference covariance matrix across array channels, enabling reconstruction of a high-ISR covariance matrix. Adaptive beamforming subsequently suppresses ISRJ signals. Simulation results validate the efficacy of the proposed method in suppressing ISRJ.