Clutter Suppression Using Thresholded Reciprocal Filter in OFDM Radar

Thresholded reciprocal filtering (TRF) techniques have been proposed as supervision strategies for reciprocal filtering (RF) in order to address the challenges posed by the unique characteristics of orthogonal frequency-division multiplexing waveforms when used for radar. These techniques are known to provide a larger flexibility for the signal processing scheme at the range compression stage by enabling the possibility to operate on signal fragments of arbitrary length, while simultaneously retaining the RF's benefits in terms of point-like target response. In this article, we extend the study of TRF techniques by presenting a theoretical analysis of their impact on the clutter suppression capability of the system. To this end, we first characterize the theoretical performance of the TRF techniques in terms of residual clutter power obtained at the output range–Doppler map. The derived analytical expressions further allow us to introduce optimized variants of the TRF, which are able to maximize the performance metrics. An extensive simulation-based validation shows that the proposed solutions outperform traditional methods, especially in low to moderate clutter-to-noise conditions. Moreover, the assessment of the proposed technique against an experimental dataset allows us to validate the practical effectiveness of the TRF approach.