Event-Based Beam Tracking with Dynamic Beamwidth Adaptation in Terahertz (THz) Communications

TL;DR

This paper introduces a novel event-based beam tracking method with dynamic beamwidth adaptation for THz communications, enhancing reliability and performance amid mobility and blockage challenges.

Contribution

It proposes a multi-objective optimization framework and a new event-triggered beam tracking approach for improved THz beam management.

Findings

Enhanced average data rate performance.

Reduced outage probability due to beam misalignment.

Reliable connectivity with minimal overhead.

Abstract

Terahertz (THz) communication will be a key enabler for next-generation wireless systems. While THz frequency bands provide abundant bandwidth and extremely high data rates, their effective operation is inhibited by short communication ranges and narrow beams, thus, leading to major challenges pertaining to user mobility, beam alignment, and handover. In particular, there is a strong need for novel beam tracking methods that consider the tradeoff between enhancing the received signal strength via increasing beam directivity, and increasing the coverage probability by widening the beam. In this paper, a multi-objective optimization problem is formulated with the goal of jointly maximizing the expected rate and minimizing the outage probability subject to transmit power and overhead constraints. Subsequently, a novel parameterized beamformer with dynamic beamwidth adaptation is proposed. In addition to the precoder, an event-based beam tracking approach is introduced that efficiently prevents outages caused by beam misalignment and dynamic blockage while maintaining a low pilot overhead. Simulation results show that the proposed beamforming scheme improves average rate performance and reduces the amount of outages caused by the brittle THz misalignment process and the particularly severe path loss in the THz band. Moreover, the proposed event-triggered THz channel estimation approach enables connectivity with minimal overhead and reliable communication at THz bands.