FM interference suppression for PRC-CW radar based on adaptive STFT

The influence of FM interference on correlation detection performance of the pseudo random code continuous wave (PRC-CW) radar is analyzed. It is found that the correlation output deteriorates greatly when the FM interference power exceeds the anti-jamming limitation of the radar. A new method is proposed based on adaptive STFT and time-varying filtering for FM interference suppression. The instantaneous phase of interference is firstly estimated utilizing adaptive STFT and the estimated phase error is decreased by means of recursive correcting. A time-varying filter based on the estimated instantaneous phase is set up to excise the interference. The echo signals corrupted by two types of interference including linear FM (LFM) and sinusoidal FM (SFM) forms under different signal-to-jamming ratio (SJR) situations are simulated. It is shown that the method can effectively suppress the FM interference and improve the performance of target detection significantly.