Adaptive direct signal and clutter cancellation based on phase-offset block least mean square filter in passive radar

The direct signal and clutter heavily degrade the performance of the target detection in passive radar. Therefore a reference antenna is necessary in order to acquire the direct signal, which is used to perform the adaptive filtering in order to cancel the direct signal and the clutter received on the surveillance antenna. However there may be distance between the two antennas, leading to reduced relativity between the reference signal and the surveillance signal. Consequently the reduced relativity results in decreased cancellation performance. In this paper a phase-offset block least mean square (BLMS) filter is designed to compensate the distance and perform the adaptive cancellation. Simulations and experiments based on real-life data is carried out to verify the effectiveness and efficiency of the proposed method.