Initial Beamforming for Millimeter-Wave and Terahertz Communications in 6G Mobile Systems

TL;DR

This paper introduces a novel initial beamforming scheme for 6G millimeter-wave and terahertz systems that achieves omni-directional coverage with high efficiency, outperforming previous methods across various array architectures.

Contribution

It proposes a new initial beamforming method using complementary beams to provide uniform coverage, applicable to all array types and architectures.

Findings

Achieves omni-directional coverage with optimal performance

Outperforms previous random beamforming scheme

Applicable to digital, analog, and hybrid arrays

Abstract

To meet the demand of supreme data rates in terabits-per-second, the next-generation mobile system needs to exploit the abundant spectrum in the millimeter-wave and terahertz bands. However, high-frequency transmission heavily relies on large-scale antenna arrays to reap high beamforming gain, used to compensate for severe propagation loss. It raises a problem of omni-directional beamforming during the phase of initial access, where a base station is required to broadcast synchronization signals and system information to all users within its coverage. This paper proposes a novel initial beamforming scheme, which provides instantaneous gain equally in all directions by forming a pair of complementary beams. Numerical results verify that it can achieve omni-directional coverage with the optimal performance that remarkably outperforms the previous scheme called random beamforming. It is applicable for any form of large-scale arrays, and all three architecture, i.e., digital, analog, and hybrid beamforming.