Time-frequency-based fm interference suppression for PRC-CW radar

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. According to the fact that the PRC-CW radar return signal is a wideband pseudo random signal occupying the whole TF plane, whereas the FM interference signal is well concentrated in the TF plane, a new method is proposed based on STFT and time- varying filtering for FM interference suppression. This method implements the filtering of the received signal by using a binary mask to excise only a portion of the TF plane corrupted by the interference. The correlation outputs 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 correlation output significantly.