Nonstationary Clutter Suppression Method for Passive Radar Based on Channel Segmentation and Smoothing

In the complex electromagnetic environment, multipath clutter in passive radar may be nonstationary and has jump characteristics. In order to suppress this kind of non-stationary clutter, a clutter suppression method is proposed based on channel segmentation and smoothing, which combines the Orthogonal Frequency Division Multiplexing (OFDM) modulation of the transmitting signal. First, the temporal domain signal model of the jumping clutter is established. Then it is transformed into subcarrier-domain by using the OFDM structure. After channel estimation of each OFDM symbol and smoothing the segmented channel estimation, the non-stationary clutter can be suppressed by the smoothed channel estimation and reference signal in each segment. Simulation and experiment data show that the proposed method can effectively suppress the non-stationary clutter with jumping characteristic.