Design of Phase-Coded Waveform and Mismatched Filter for Countering Interrupted-Sampling Repeater Jamming

Interrupted-sampling repeater jamming (ISRJ) utilizes the characteristics of signal undersampling and matched filtering to produce multiple controllable numbers of false target points in the range direction, which seriously affects radar target tracking and identification, and is widely used in electronic countermeasures. For ISRJ suppression, this paper proposes a joint design method of phase-coded (PC) waveform and mismatched filter, leveraging known partial jamming parameters. According to the ISRJ characteristics and jamming parameters, the optimal transmitting waveform is designed by using the principle of mismatched filtering. After receiving the echo with jamming, a mismatched filter design approach is proposed using the ISRJ sampling function and designed coded waveform to enhance ISRJ suppression for optimal countermeasure effectiveness. The entire design process is divided into two parts, which respectively address the issues of waveform design and mismatched filter design. Subsequently, the proposed method's feasibility and effectiveness are validated through multiple simulations. The simulation results demonstrate that the PC waveform and mismatching filter optimized by this method exhibit superior ISRJ suppression.