User-Movement-Robust Virtual Reality Through Dual-Beam Reception in mmWave Networks

TL;DR

This paper proposes a dual-beam reception method in mmWave networks to improve VR connectivity robustness against user movement, significantly reducing outage rates by leveraging cooperative APs and analog beamforming.

Contribution

It introduces a novel dual-beam reception technique at the HMD that enhances signal robustness and diversity in dynamic VR scenarios using mmWave cooperative networks.

Findings

Up to 13% outage reduction with dual-beam reception

17% outage decrease compared to steerable single-beam approach

Widening AP separation further reduces outage rates during head rotation

Abstract

Utilizing the mmWave band can potentially achieve the high data rate needed for realistic and seamless interaction within a virtual reality (VR) application. To this end, beamforming in both the access point (AP) and head-mounted display (HMD) sides is necessary. The main challenge in this use case is the specific and highly dynamic user movement, which causes beam misalignment, degrading the received signal level and potentially leading to outages. This study examines mmWave-based coordinated multi-point networks for VR applications, where two or multiple APs cooperatively transmit the signals to an HMD for connectivity diversity. Instead of using omnireception, we propose dual-beam reception based on the analog beamforming at the HMD, enhancing the receive beamforming gain towards serving APs while achieving diversity. Evaluation using actual HMD movement data demonstrates the effectiveness of our approach, showcasing a reduction in outage rates of up to 13% compared to quasi-omnidirectional reception with two serving APs, and a 17% decrease compared to steerable single-beam reception with a serving AP. Widening the separation angle between two APs can further reduce outage rates due to head rotation as rotations can still be tracked using the steerable multi-beam, albeit at the expense of received signal levels reduction during the non-outage period.