UAV SAR Imaging with 5G NR OFDM Signals in NLOS Environments

TL;DR

This paper introduces a cooperative ISAC framework using 5G NR OFDM signals for UAV SAR imaging in NLOS environments, employing advanced compressed sensing techniques for high-precision scatterer localization.

Contribution

It proposes a novel cooperative ISAC approach that leverages OFDM signals and a two-stage CS-SAGE scheme for improved SAR imaging in challenging NLOS conditions.

Findings

Effective detection of weak signals in NLOS environments

High-precision scatterer localization demonstrated through simulations

Framework provides insights for practical system design

Abstract

The integration of sensing and communication (ISAC) has significant potential for future wireless systems, enabling efficient spectrum utilization and novel application scenarios. In this paper, we propose a cooperative ISAC framework for synthetic aperture radar (SAR) imaging by leveraging orthogonal frequency division multiplexing (OFDM) communication signals. We address the challenge of severe imaging degradation in non-line-of-sight (NLOS) environments under the QUAsi Deterministic RadIo channel GenerAtor (QuaDRiGa). To detect weak signals and eliminate false points, we develop a two-stage compressed sensing-space alternating generalized expectation maximization (CS-SAGE) scheme for high-precision scatterer localization. In stage I, orthogonal matching pursuit (OMP) is employed for coarse estimation to identify the approximate locations of dominant scatterers. Then, the SAGE algorithm in stage II performs fine estimation to accurately extract scatterer parameters. Simulation results validate the effectiveness of the proposed cooperative ISAC framework, and provide valuable insights for practical system design.