Near-Field Beamforming for Large Intelligent Surfaces

Loading...
Thumbnail Image

Access rights

openAccess

URL

Journal Title

Journal ISSN

Volume Title

A4 Artikkeli konferenssijulkaisussa

Date

2022

Major/Subject

Mcode

Degree programme

Language

en

Pages

7
1367-1373

Series

2022 IEEE 33rd Annual International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC 2022, IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC, Volume 2022-September

Abstract

In this paper, we propose a novel near-field beamforming (BF) design with a Large Intelligent Surface (LIS) that is implemented as a discretized 2D-array. We first investigate the definitions of the near-field and far-field regions, and determine the Fraunhofer distance of the LIS, which scales up linearly in the surface-area of the LIS. Hence, a user-equipment (UE) can enter the near-field of a LIS in practice. In addition to Fraunhofer distance, we further derive the Fresnel near-field region where both amplitude and angle variations are negligible, as long as the distance from the UE to the LIS is larger than a threshold, which only scales up linearly in the diameter of LIS. Therefore, in the majority region of near-field, only phase variations worsen the the quality of received signal and result in significant array-gain losses. Motivated by this observation, we further propose a two-step near-field BF design that can effectively recover the array-gain losses in Fresnel near-field, and is fully compatible with a conventional far-field BF.

Description

Publisher Copyright: © 2022 IEEE.

Keywords

Other note

Citation

Hu, S, Ilter, M C & Wang, H 2022, Near-Field Beamforming for Large Intelligent Surfaces . in 2022 IEEE 33rd Annual International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC 2022 . IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, vol. 2022-September, IEEE, pp. 1367-1373, IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, Virtual, Online, Japan, 12/09/2022 . https://doi.org/10.1109/PIMRC54779.2022.9977582