Robust Adaptive Time-Frequency Filtering for Frequency Shift Jamming Suppression

Frequency shift jamming (FSJ) significantly challenges the detection performance of radar with the linear frequency modulation (LFM) waveform, since jamming signals keep LFM coherence with only frequency shift modulation. In this article, an adaptive time-frequency filtering algorithm is developed, which exploits the different time-frequency relationships between FSJ signals and true targets to construct the adaptive suppression filters. The difference in the filtering energy loss ratio is measured by clustering technique to determine the FSJ targets. Extensive simulation experiments show that the proposal performs effectively and stably for FSJ suppression.