NBA-OMP: Near-field Beam-Split-Aware Orthogonal Matching Pursuit for Wideband THz Channel Estimation

TL;DR

This paper introduces NBA-OMP, a novel near-field beam-split-aware orthogonal matching pursuit method, to improve wideband THz channel estimation by mitigating near-field beam-split effects using a specially designed dictionary.

Contribution

The paper proposes a new NB-aware OMP algorithm with a tailored dictionary to enhance wideband THz channel estimation accuracy, addressing near-field beam-split issues.

Findings

NBA-OMP significantly improves channel estimation accuracy in simulations.

The method effectively mitigates near-field beam-split effects.

Numerical results outperform existing approaches.

Abstract

The sixth-generation networks envision the terahertz (THz) band as one of the key enabling technologies because of its ultrawide bandwidth. To combat the severe attenuation, the THz wireless systems employ large arrays, wherein the near-field beam-split (NB) severely degrades the accuracy of channel acquisition. Contrary to prior works that examine only either narrowband beamforming or far-field models, we estimate the wideband THz channel via an NB-aware orthogonal matching pursuit (NBA-OMP) approach. We design an NBA dictionary of near-field steering vectors by exploiting the corresponding angular and range deviation. Our OMP algorithm accounts for this deviation thereby ipso facto mitigating the effect of NB. Numerical experiments demonstrate the effectiveness of the proposed channel estimation technique for wideband THz systems.