Low-Complexity Near-Field Localization with XL-MIMO Sectored Uniform Circular Arrays

TL;DR

This paper introduces a low-complexity near-field localization method for XL-MIMO arrays using a sectored uniform circular array, improving accuracy and speed over traditional algorithms.

Contribution

It proposes a novel backprojection algorithm tailored for sUCA, with analytical resolution analysis and FFT-based implementation for efficiency.

Findings

Outperforms conventional algorithms in localization accuracy

Achieves hundreds of times faster runtime with FFT implementation

Provides analytical insights into resolution and antenna requirements

Abstract

Rapid advancement of antenna technology catalyses the popularization of extremely large-scale multiple-input multiple-output (XL-MIMO) antenna arrays, which pose unique challenges for localization with the inescapable near-field effect. In this paper, we propose an efficient near-field localization algorithm by leveraging a sectored uniform circular array (sUCA). In particular, we first customize a backprojection algorithm in the polar coordinate for sUCA-enabled near-field localization, which facilitates the target detection procedure. We then analyze the resolutions in both angular and distance domains via deriving the interval of zero-crossing points, and further unravel the minimum required number of antennas to eliminate grating lobes. The proposed localization method is finally implemented using fast Fourier transform (FFT) to reduce computational complexity. Simulation results verify the resolution analysis and demonstrate that the proposed method remarkably outperforms conventional localization algorithms in terms of localization accuracy. Moreover, the low-complexity FFT implementation achieves an average runtime that is hundreds of times faster when large numbers of antenna elements are employed.