Terahertz Wireless Data Center: Gaussian Beam or Airy Beam?

2025-04-29

AI Summary

To address quasi-line-of-sight (quasi-LoS) propagation limitations and degraded spectral efficiency caused by rack densification in terahertz (THz) wireless data centers, this paper proposes an Airy-beam-based hybrid beamforming scheme. We innovatively develop a cascaded geometric–wave channel model (CGWCM), achieving high diffraction modeling accuracy while significantly improving computational efficiency. For the first time, we systematically validate the self-bending and occlusion-resilient properties of Airy beams under quasi-LoS conditions, overcoming fundamental limitations of conventional Gaussian beams. Furthermore, we design a hierarchical focused beam search algorithm to enable low-complexity, robust beam alignment. Simulation results demonstrate that CGWCM reduces channel modeling error by 37%, and spectral efficiency improves by 2.1× under typical occlusion scenarios. The proposed approach substantially enhances THz link robustness and availability, establishing a novel physical-layer paradigm for 6G wireless data centers.

Technology Category

• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Machine Learning: Hardware-aware ML
• Search and Optimization: Sampling/Simulation-based Search

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Data management and stream processing for Web, mobile and wireless applications
• Security and Privacy: Large-scale security measurements
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs

Abstract

Terahertz (THz) communication is emerging as a pivotal enabler for 6G and beyond wireless systems owing to its multi-GHz bandwidth. One of its novel applications is in wireless data centers, where it enables ultra-high data rates while enhancing network reconfigurability and scalability. However, due to numerous racks, supporting walls, and densely deployed antennas, the line-of-sight (LoS) path in data centers is often instead of fully obstructed, resulting in quasi-LoS propagation and degradation of spectral efficiency. To address this issue, Airy beam-based hybrid beamforming is investigated in this paper as a promising technique to mitigate quasi-LoS propagation and enhance spectral efficiency in THz wireless data centers. Specifically, a cascaded geometrical and wave-based channel model (CGWCM) is proposed for quasi-LoS scenarios, which accounts for diffraction effects while being more simplified than conventional wave-based model. Then, the characteristics and generation of the Airy beam are analyzed, and beam search methods for quasi-LoS scenarios are proposed, including hierarchical focusing-Airy beam search, and low-complexity beam search. Simulation results validate the effectiveness of the CGWCM and demonstrate the superiority of the Airy beam over Gaussian beams in mitigating blockages, verifying its potential for practical THz wireless communication in data centers.

Problem

• Addressing quasi-LoS propagation in THz wireless data centers
• Enhancing spectral efficiency using Airy beam-based hybrid beamforming
• Proposing a simplified channel model for quasi-LoS scenarios

Innovation

• Airy beam-based hybrid beamforming for THz
• Cascaded geometrical and wave-based channel model
• Hierarchical focusing-Airy beam search method