Advanced multipath clutter cancellation in OFDM-based passive radar systems

We present an advanced algorithm to suppress multipath clutter in passive radar systems using OFDM signals for surveillance. Multipath clutter signals not only lead to enormous zero Doppler signals in the range Doppler domain, they also induce intense side lobes when the multipath signals have additional small Doppler shifts to the reference signal and thereby can mask targets with small Doppler frequencies and small SNR. The proposed algorithm, denominated as Enhanced Cancellation Algorithm by Carrier and Doppler Shift (ECA-CD), removes multipath clutter signals and reduces its side lobes. Its implementation and experimental tests show the effectiveness of multipath signal suppression in real time.