A subbandadaptive filter for DTV based passive radar

In passive radar, the direct and multipath interference in echo channel must be suppressed before target detection. As the bandwidth of the digital television(DTV) signal is quite broad, when target detection is performed utilizing DTV signal, the inconsistency of the reference channel and the echo channel will leads to the degradation of the cancellation gain and radar operation range. To solve this problem, a novel interference suppression approach is proposed. First, the direct wave and the echo signals are decomposed into subbands and downsampled; then in each subband, signal passes through a Wiener filter; last, the final output can be obtained by synthesizing the interpolated results of the subband filtering. Experimental results demonstrate that the proposed method improves the cancellation performance effectively.