AoA Estimation for OAM Communication Systems With Mode-Frequency Multi-Time ESPRIT Method

TL;DR

This paper introduces a novel mode-frequency multi-time ESPRIT method for accurate AoA estimation in OAM communication systems, significantly reducing misalignment errors and improving alignment performance.

Contribution

It presents an easier-to-implement AoA estimation technique using multiple ESPRIT applications in mode and frequency domains, enhancing OAM channel alignment.

Findings

Reduces misalignment errors in OAM channels

Performance approaches ideal alignment levels

Simplifies AoA estimation process

Abstract

Radio orbital angular momentum (OAM) communications require accurate alignment between the transmit and receive beam directions. Accordingly, a key feature of OAM receivers is the ability to reliably estimate the angle of arrival (AoA) of multi-mode OAM beams. Considering the limitations of existing AoA estimation techniques, in this paper, we propose an easier-to-implement AoA estimation method based on applying multiple times the estimating signal parameters via rotational invariance techniques (ESPRIT) algorithm to the received training signals in OAM mode and frequency domains, which is denoted as the mode-frequency (M-F) multi-time (MT)-ESPRIT algorithm. With this method, the misalignment error of real OAM channels can be greatly reduced and the performance approaches that of ideally aligned OAM channels.