Beam-Squint-Aided Hierarchical Sensing for Integrated Sensing and Communications with Uniform Planar Arrays

TL;DR

This paper introduces a hierarchical sensing framework leveraging beam-squint effects in wideband systems with UPAs, enabling efficient 2D angle estimation and target localization for integrated sensing and communications.

Contribution

It presents a novel hierarchical sensing approach that uses beam-squint effects and sparse recovery, improving efficiency and reducing power consumption in wideband UPA systems.

Findings

Achieves superior sensing performance compared to conventional methods.

Reduces sensing power while maintaining accuracy.

Effectively estimates 2D angles using a multi-stage process.

Abstract

In this paper, we propose a novel hierarchical sensing framework for wideband integrated sensing and communications with uniform planar arrays (UPAs). Leveraging the beam-squint effect inherent in wideband orthogonal frequency-division multiplexing (OFDM) systems, the proposed framework enables efficient two-dimensional angle estimation through a structured multi-stage sensing process. Specifically, the sensing procedure first searches over the elevation angle domain, followed by a dedicated search over the azimuth angle domain given the estimated elevation angles. In each stage, true-time-delay lines and phase shifters of the UPA are jointly configured to cover multiple grid points simultaneously across OFDM subcarriers. To enable accurate and efficient target localization, we formulate the angle estimation problem as a sparse signal recovery problem and develop a modified matching pursuit algorithm tailored to the hierarchical sensing architecture. Additionally, we design power allocation strategies that minimize total transmit power while meeting performance requirements for both sensing and communication. Numerical results demonstrate that the proposed framework achieves superior performance over conventional sensing methods with reduced sensing power.