Interrupted-Sampling Repeater Jamming Recognition Based on PC-LFM Waveform Processing

The interrupted-sampling repeater jamming (lSRJ) generates a series of false targets after pulse compression by quickly sampling and forwarding radar signals, which poses a significant threat to radar performance. In order to facilitate the elimination of the periodic forwarding compound ISRJs, this paper focuses on discriminating between targets and ISRJ based on the phase-coded linear frequency modulation (PC-LFM) waveform. At the transmission stage, the peak sidelobe level (PSL) of the PC-LFM waveform's auto-correlation is minimized using an integrated Riemannian manifold optimization solver to enhance target detection capabilities. Taking advantage of the energy-reduction effect of the decoding operation in the PC-LFM on non-detection delay signals, a feature extraction scheme is developed to explore the disparity characteristic between the target and the ISRJ in the range profile. Subsequently, the PC-LFM-based recognition (PCLFM-R) algorithm is provided based on the feature difference in the number of peaks and the width of the mainlobe. Moreover, decoding filters are designed to improve recognition accuracy further, leading to a modified PCLFM-R (M-PCLFM-R) procedure. Numerical results demonstrate the effectiveness of the proposed PCLFM-R and M-PCLFM-R approaches in discrimination targets and ISRJ under several aliasing interferences.