Reduced Complexity Multipath Clutter Rejection Approach for DRM-Based HF Passive Bistatic Radar

Clutter rejection is a key technique in digital radio Mondiale (DRM)-based HF passive bistatic radar, because the power of a target signal is many orders of magnitude weaker than the direct-path wave and multipath echoes. Many temporal approaches can be used to reject the multipath clutter. We proposed a novel approach which takes full advantage of characteristic of the transmitted waveform. DRM signal is based on the orthogonal frequency division multiplexing modulation technique. After the temporal signal model in subcarrier domain is analyzed, an approach using recursive least square adaptive filter is introduced to remove unwanted components on each effective subcarrier. It has low computational complexity. Simulation and experiment data verification are carried out, which proved the efficiency of the proposed approach.