Initial Access for Millimeter-Wave and Terahertz Communications with Hybrid Beamforming

TL;DR

This paper introduces a hybrid beamforming scheme for initial access in mmWave and THz 6G systems, enabling omnidirectional broadcasting with high gain and outperforming previous methods.

Contribution

It proposes a novel hybrid beamforming approach that achieves omnidirectional coverage for initial access in high-frequency wireless systems.

Findings

Achieves omnidirectional coverage with high performance

Outperforms previous broadcasting schemes

Verifies effectiveness through numerical simulations

Abstract

In order to achieve terabits-per-second (Tbps) data rates in the sixth-generation (6G) mobile system, wireless communications are required to exploit the abundant spectrum in the millimeter-wave (mmWave) and terahertz (THz) bands. However, high-frequency transmission heavily relies on high beamforming gain to compensate for severe propagation loss. A beam-based system faces a barrier in the process of initial access, where a base station must broadcast synchronization signals and system information to all users within its coverage. Hence, this paper proposes a novel omnidirectional broadcasting scheme for mmWave and THz systems with hybrid beamforming. It provides an instantaneously equal gain over all directions by forming complementary beams over sub-arrays. Numerical results verify that it can achieve omnidirectional coverage with a performance that remarkably outperforms the previous scheme.