An Interrupted Sampling Repeater Jamming Suppression Algorithm Combines Grey Entropy With Multidimensional Filtering

Interrupted sampling repeater jamming (ISRJ), as a typical intra-pulse coherent interference, seriously endangers the performance of radar. To effectively suppress ISRJ, the paper proposes an ISRJ suppression algorithm combines grey entropy with multidimensional filtering. Firstly, the grey entropy algorithm from image segmentation is introduced to extract interference-free segments enhancing the accuracy of intrapulse interference-free segments extraction. Secondly, a fractional-order domain filter is constructed using the interference-free segments to conduct the primary suppression of interference in the fractional-order domain. Then, a time-frequency filter is constructed based on dechirped interference-free segments to suppress the interference again in the frequency domain. Finally, leveraging the linear relationship between frequency and distance of target in dechirped radar received signals, and the pulse compression results after interference suppression are obtained. Simulation experiments validate the effectiveness and robustness of the proposed algorithm. Compared with the same type of algorithms, the proposed algorithm demonstrates improved interference suppression performance under low signal-to-noise ratio (SNR) or high jamming-to-signal ratio (JSR) conditions.