Millimeter-Wave True-Time Delay Array Beamforming with Robustness to Mobility

TL;DR

This paper introduces a novel true-time delay array beamforming technique using frequency-dependent slanted beams to enhance robustness and reliability in mmWave networks with mobile users, addressing connectivity challenges in high-mobility scenarios.

Contribution

It proposes a new beamforming method with linear angle-frequency relationships that improves reliability and adaptability over existing analog array designs in wideband, multi-user mmWave systems.

Findings

Slanted beams offer higher reliability to angle offsets.

The method provides better adaptability to user movement.

Trade-offs between capacity and coverage are demonstrated.

Abstract

Ultra-reliable and low-latency connectivity is required for real-time and latency-sensitive applications, like wireless augmented and virtual reality streaming. Millimeter-wave (mmW) networks have enabled extremely high data rates through large available bandwidths but struggle to maintain continuous connectivity with mobile users. Achieving the required beamforming gain from large antenna arrays with minimal disruption is particularly challenging with fast-moving users and practical analog mmW array architectures. In this work, we propose frequency-dependent slanted beams from true-time delay (TTD) analog arrays to achieve robust beamforming in wideband, multi-user downlink scenarios. Novel beams with linear angle-frequency relationships for different users and sub-bands provide a trade-off between instantaneous capacity and angular coverage. Compared to alternative analog array beamforming designs, slanted beams provide higher reliability to angle offsets and greater adaptability to varied user movement statistics.