Capacity Analysis on OAM-Based Wireless Communications: An Electromagnetic Information Theory Perspective

TL;DR

This paper introduces an electromagnetic information theory approach to analyze OAM-based wireless communications, revealing capacity enhancements and parameter impacts that classical models overlook.

Contribution

It integrates electromagnetic theory with classical information theory to better analyze and optimize OAM-based wireless systems, addressing limitations of traditional scalar models.

Findings

Channel capacity can be significantly improved using EIT-based analysis.

Numerical results confirm capacity enhancement with electromagnetic considerations.

Parameter variations notably affect system capacity and performance.

Abstract

Orbital angular momentum (OAM) technology enhances the spectrum and energy efficiency of wireless communications by enabling multiplexing over different OAM modes. However, classical information theory, which relies on scalar models and far-field approximations, cannot fully capture the unique characteristics of OAM-based systems, such as their complex electromagnetic field distributions and near-field behaviors. To address these limitations, this paper analyzes OAM-based wireless communications from an electromagnetic information theory (EIT) perspective, integrating electromagnetic theory with classical information theory. EIT accounts for the physical properties of electromagnetic waves, offering advantages such as improved signal manipulation and better performance in real-world conditions. Given these benefits, EIT is more suitable for analyzing OAM-based wireless communication systems. Presenting a typical OAM model utilizing uniform circular arrays (UCAs), this paper derives the channel capacity based on the induced electric fields by using Green's function. Numerical and simulation results validate the channel capacity enhancement via exploration under EIT framework. Additionally, this paper evaluates the impact of various parameters on the channel capacity. These findings provide new insights for understanding and optimizing OAM-based wireless communications systems.