A Novel Waveform Design Method for Shift-Frequency Jamming Confirmation

Abstract

Shift-frequency jamming is generally used to form range false targets for ground-based early-warning radar systems; the frequency shift value of such interference is larger than the Doppler shift value of the moving target, and the key element to suppress the shiftfrequency jamming is the frequency shift value estimation. However, in the low-or medium-pulse repetition frequency (PRF) mode, it is challenging to estimate the accurate frequency shift due to the velocity ambiguity. To solve this problem, a novel sparse Doppler-sensitive waveform is designed based on the ambiguity function theory, where the basic idea is to design a waveform sensitive to a specific Doppler but insensitive to other Dopplers; therefore, this waveform can recognize the specific Doppler of the target unambiguously. To apply the designed waveform in practice, the detection and estimation processing flow is provided based on the waveform diversity technique and the family of the sparse Doppler-sensitive waveforms. Simulation experiments are presented to validate the efficiency of the proposed method, and we conclude that the advantage of this method is that it can be used to confirm the specific Doppler of the target unambiguously with few pulses even under the condition of a low PRF.

Sensing Matrix Optimization for Random Stepped-Frequency Signal Based on Two-Dimensional Ambiguity Function

“…According to the relationship of sparse reconstruction performance of SRSFs and TDAF, the optimal frequency step mode of SRSFs is obtained by designing TDAF with low sidelobe level. Then, based on (23), the object of mutual coherence minimization can be transformed into the following TDAF maximum sidelobe minimization problem.…”

“…In addition, integrated sidelobe level (ISL) is another commonly used measure for sidelobe level of the AF [21], hence, an iterative sparse frequency waveform optimization method with low ISL is proposed in [22]. Moreover, in [23], both PSL and ISL have been used for sparse waveform design. In addition, in order to overcome the Doppler ambiguity, a sparse Doppler-sensitive waveform design method is proposed in [24] based on the specific Doppler cut of AF.…”