Passive detection using orthogonal frequency division multiplex signals of opportunity without multipath clutter cancellation

This study examines target detection in passive bistatic radar (PBR) using orthogonal frequency division multiplex (OFDM) signals. Most of the existing methods focus on multipath clutter cancellation prior to matched filter, which usually lead to intensive computational load. However, the detection methods exploiting the distinguished characteristics of OFDM signals have been studied much less. The published OFDM-specific methods have opened up the new possibility of target detection without multipath clutter cancellation, whereas having detrimental effects on the floor level of cross ambiguity surface because of the inter-symbol interference (ISI) and inter-carrier interference (ICI). A novel OFDM-specific method is proposed herein to feasibly extract the weak target echoes against the strong multipath clutter by low-complexity suppression of the Doppler sidelobes resulting from the ISI and ICI. The simulated and experimental results following the robustness analysis validate the effectiveness of the proposed method, which provides a valuable basis for real-time signal processing in PBR.