Multipath Suppression for Continuous Wave Radar via Slepian Sequences

• Published in: IEEE transactions on signal processing Vol. 68; pp. 548 - 557
• Main Authors: Day, Brian P., Evers, Aaron, Hack, Daniel E.
• Format: Journal Article
• Language: English
• Published: New York IEEE 2020; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Clutter; Computing costs; Continuous wave radar; Delays; Doppler effect; Doppler radar; least squares approximation; Matched filters; Matching pursuit algorithms; Post-processing; projection algorithms; Radar clutter; Radar equipment; Rejection; RF signals; Signal processing; Target masking
• ISSN: 1053-587X; 1941-0476
• DOI: 10.1109/TSP.2020.2964199

In continuous wave (CW) radar systems, multiple signal copies impinge the receiver simultaneously. Often, undesired multipath and direct-path copies are many times stronger than potential targets. When applying matched filter signal processing techniques, the undesired signal components can mask weaker targets and decrease performance of post-processing techniques, such as target indication or estimation. In this manuscript, we propose a method of rejecting multipath-scattered returns over a continuous region in range and Doppler. We explore the computational cost of this method and additionally propose an approximate method of rejection which leverages the well-known discrete prolate spheroidal sequences (DPSS)-typically referred to as Slepian sequences-to gain a computational advantage. Results are shown to decrease the effective noise floor when applying matched filtering techniques as well as increase target signal-to-interference-plus-noise ratio (SINR) outside of an undesired multipath region. Comparisons are shown to traditional CW multipath removal in terms of rejection performance and run-time.