Near Range, Leakage Aware Object Localization Based on 5G NR-Compliant JCAS

In this work, we investigate joint communications and sensing (JCAS) with a 5G New Radio (NR)-compliant orthogonal frequency-division multiplexing (OFDM) system. The focus lies on the special task of estimating the distances of objects in the close proximity of the antenna from a user equipment (UE) point of view. Unfortunately, in the range spectrum such near range objects may be covered by a leakage signal arising from the own transmitter. The interfering signal is typically much stronger in signal power compared to the objects' reflections. Thus, for close objects, classical OFDM-based radar processing methods as well as advanced algorithms like multiple signal classification (MUSIC) are in many situations not able to separate the objects and the leakage. In this work, we propose a modified version of the sparse cyclic coordinate decent (SCCD) algorithm by combining it with the so-called RELAX method to separate and estimate the positions of the leakage and the objects. A proof of concept is presented via simulations and measurements, which highlights that the proposed method outperforms state-of-the-art (SOTA) algorithms, particularly in the mid signal-to-noise ratio (SNR) range.