Clutter Suppression Using Thresholded Reciprocal Filter in OFDM Radar

• Published in: IEEE transactions on aerospace and electronic systems pp. 1 - 15
• Main Authors: Quirini, Andrea, Colone, Fabiola, Lombardo, Pierfrancesco
• Format: Journal Article
• Language: English
• Published: IEEE 11.07.2024
• Subjects: Clutter; Clutter cancellation; OFDM; OFDM radar; Passive radar; Radar clutter; Radio frequency; Signal to noise ratio; supervised reciprocal filter; Symbols
• ISSN: 0018-9251; 1557-9603
• DOI: 10.1109/TAES.2024.3427089

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 (OFDM) 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 paper 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 firstly 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, that 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.