Countering self‐protection smeared spectrum jamming against chirp radars

Abstract

Chirp radars are vulnerable to various types of deceptive jamming for example, smeared spectrum (SMSP) jamming that generates multiple false targets, which lead and lag the true target. Unfortunately, the radar system cannot distinguish the true target from the false ones because the jamming signal looks like the true target echo. A new anti-jamming technique to suppress false targets and identify the true target easily is introduced. The proposed technique benefits from the fact that SMSP jamming signal has a different frequency modulation slope from that of the radar signal. Therefore, the differences between SMSP jamming signal and the true target echo can be identified. The efficiency of the proposed technique is confirmed by theoretical analysis and simulation experiments. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Countering self-protection interrupted sampling repeater jammer against chirp radar

“…Compared with FT, the FrFT of optimal angle, α opt , applied to a chirp pulse, concentrates its energy distribution in the fractional domain. This presents the use of the FrFT for pulse compression of chirp pulse [27–30, 34–37]. The continuous FrFT of a signal x ( t ) is given by [31, 32]:where is the transform kernel and when α ≠ nπ it equals [31, 32]:where and .…”

“…This equation is equivalent to that of the matched filter for chirp pulse. This means that the FrFT compresses chirp pulse like matched filter does [27–30, 34–37]. But, the matched filter is superior to FrFT by 3 dB [36].…”

“…But, that anti-jamming method cannot counter ISRJ because both the true target and the main false 1461 International Journal of Microwave and Wireless Technologies target have the same frequency shift, and therefore the true target cannot be distinguished from the main false one. In [30], FrFT is used for countering smeared spectrum jamming, where the antijamming method benefits from the fact that the jamming pulses have a different frequency modulation slope from that of the transmitted radar chirp. Therefore, the jamming pulses can be suppressed in the fractional domain, and then the true target can be distinguished easily.…”

Deep Learning-Based Active Jamming Suppression for Radar Main Lobe

“…In addition, Ly et al [6] developed a CNN-based method for ISRJ identification and antijamming target detection. FrFT was applied to counter SMSP jamming in distributed radar due to distinct FM slopes between spectrum dispersive jamming and radar signals [7]. Multiple studies [8][9][10] examined jamming suppression in distributed radar systems, identifying jamming signals by analyzing unique spatial scattering traits that differentiate genuine target echoes from deceptive jamming.…”

SMSP Mainlobe Jamming Suppression with FDA-MIMO Radar Based on FastICA Algorithm

“…Sparrow and Cikalo (2006) invented mainlobe SMSP jamming to counter pulse compression (PC) radars, which can generate a large number of range false targets (RFTs) in LFM-PC ranging radars. This is a nonstationary time-varying (TV) signal that can be regarded as the sum of multiple chirps [ 14 , 15 ]. SMSP jamming has the same bandwidth as the radar detection waveform, which can obtain the gain of pulse compression to achieve a better effect.…”