Terahertz-Band Direction Finding With Beam-Split and Mutual Coupling Calibration

TL;DR

This paper addresses the challenges of beam-split and mutual coupling in terahertz band systems for 6G, proposing a novel calibration method to improve direction-of-arrival estimation accuracy.

Contribution

It introduces the CREAM-MUSIC algorithm, a subspace-based approach that compensates for beam-split and mutual coupling effects in THz systems.

Findings

Accurately estimates DoAs despite beam-split effects

Effectively compensates for mutual coupling

Demonstrates robustness through numerical simulations

Abstract

Terahertz (THz) band is currently envisioned as the key building block to achieving the future sixth generation (6G) wireless systems. The ultra-wide bandwidth and very narrow beamwidth of THz systems offer the next order of magnitude in user densities and multi-functional behavior. However, wide bandwidth results in a frequency-dependent beampattern causing the beams generated at different subcarriers split and point to different directions. Furthermore, mutual coupling degrades the system's performance. This paper studies the compensation of both beam-split and mutual coupling for direction-of-arrival (DoA) estimation by modeling the beam-split and mutual coupling as an array imperfection. We propose a subspace-based approach using multiple signal classification with CalibRated for bEAam-split and Mutual coupling (CREAM-MUSIC) algorithm for this purpose. Via numerical simulations, we show the proposed CREAM-MUSIC approach accurately estimates the DoAs in the presence of beam-split and mutual coupling.