A Frequency Domain Clutter Suppression Approach for Passive Radar

Passive radar (PR) often suffers from the direct-path and multipath clutter interference, causing the target echo to be submerged by clutter, so the clutter must be suppressed at first. A novel approach to suppress clutter effectively is proposed. First, the reference and surveillance signals are divided into multiple short segments, and then the segmented signals are transformed from time domain to frequency domain. Subsequently, clutter suppression is performed on each frequency bin. Finally, the surveillance signal after clutter suppression is transformed back to the time domain. Compared with conventional clutter suppression methods, the proposed method does not require the high-order computation adopted by adaptive filtering, thus reducing the computational complexity significantly. Furthermore, the proposed method is not confined to orthogonal frequency division multiplex (OFDM) signal, making it widely applicable. The superiority of the proposed method is demonstrated by application to simulated and experimental data.