Study on interrupted-sampling repeater jamming performance based on intra-pulse frequency coded signal

Band pass filter design against interrupted‐sampling repeater jamming based on time‐frequency analysis

“…Since the false targets formed by the directly retransmitted ISRJ signal are farther than the real one in the range domain, Li, et al [13] presented an improved ISRJ method to obtain a train of false targets that precede the true one, which makes the victim radar unable to identify the true target by range relationships. Shen et al [15] studied the performance of ISRJ based on the intra‐pulse frequency coded signal and found that the ISRJ of the random frequency coded signal can only form a single false target in direct forwarding mode, which is different from a group of false targets of the ISRJ of the LFM signal, and the ISRJ performance will be reduced with the increasing of the sub‐pulse number. However, this kind of waveform cannot fully eliminate the false target.…”

ECCM Scheme against Interrupted Sampling Repeater Jammer Based on Parameter-Adjusted Waveform Design

“…In [ 13 ], we declared that the intra-pulse frequency coded signal has significant performance for ECCM, which only forms a single false target after matched filtering with proper parameter setting. We thus firstly analyze the influence on ECCM performance with different waveform parameters, and then a parameter-adjusted IPFC waveform is designed based on the estimated parameters above.…”

“…According to [ 13 ], we know that the ISRJ of random signal through the matched filter can always form a single false target that delays behind the real target because of the uncorrelation between the jamming and the impulse response of the matched filter, which is mainly caused by the random frequency code. Moreover, as for random signal, it is unnecessary to meet the condition between the sub-pulse duration and pulse repeat interval, namely, which is rather critical in an intra-pulse frequency coded signal design to assure that uncorrelation and enhance the ECCM performance for ISRJ.…”

“…For example, Letao Xu (2012) analyzed the ISRJ effect on phase coded (PC) signal in [ 11 ] and pointed out that ISRJ is not sensitive to the coding mode of the phase coded signal, and can only form a single false target behind the real target. Rui Shen (2016) highlighted that an efficient jamming effect on an intra-pulse frequency coded (IPFC) signal [ 12 ] can be achieved only using the periodic repeater method with appropriate parameters [ 13 ]. The above references indicate that some inner-pulse modulated signals with appropriate parameters may have preferable anti-jamming performance compared to the LMF signal, because the corresponding ISRJ signals, after matched filtering, always form a single false target.…”

A Novel Radar Waveform Design for Anti-Interrupted Sampling Repeater Jamming via Time-Frequency Random Coded Method

“…As a classic jamming type derived from digital radio frequency memory (DRFM) [1][2][3], the ISRJ is more likely to generate multiple false targets after pulse compression because of its strong correlation with radar signals. The new ISRJ patterns include frequency shift modulation [4], smart noise modulation [5], interrupted sampling signal modulation [6][7][8], etc. However, compared with interference technology, the research of anti-ISRJ interference technology [9] is relatively insufficient, most of which are aimed at radar echo signals, and anti-jamming processing is performed in the signal processing stage, such as filter design methods.…”