Dealing with co-channel interference in multi-channel airborne passive radar

We address the problem of co-channel interference (CCI) in multi-channel airborne passive radars using digital broadcast signals of opportunity. A framework for suppressing the CCI is proposed, based on a two-stage approach, which reflects the range–Doppler map being a function of both a reference and a surveillance signal. In the first stage, the multiple receiving channels are used to reduce the CCI and hence improve the reconstruction of the digital reference signal. In the second stage, multi-channel processing in the range–Doppler domain is performed to further limit the effects of CCI. For each CCI suppression stage, several filters are proposed and their performances are evaluated against real data.