A Clutter Suppression Method for Diverse Pulse Train with Different Intra-Pulse Frequency Coding

摘要

Frequency coded signal possesses attractive performance on low probability of intercept (LPI) and electronic counter-countermeasure (ECCM). However, due to the high sidelobe characteristics of the signal, the effect of clutter should be considered in target detection. In this paper an approach for diverse pulse train with different frequency coding is proposed that enables to detect remote target under strong clutter. By modulating different frequency code sequences between pulses, the range gating can be realized. Then, a frequency domain mismatched filter is constructed to suppress sidelobe. On this basis, a clutter suppression procedure is performed on the range subinterval where strong clutter is located. Finally, the range-Doppler resolution of a target is obtained by two-dimensional (2-D) matched filtering. The simulation results show that the method can effectively suppress folded clutter and improve remote weak targets detection capability of the radar. Besides, two-dimensional matched filtering can effectively solve the envelope migration problem caused by velocity and the Doppler sensitivity problem of the signal, thus reducing the coherent integration loss.