An NLoS-based Enhanced Sensing Method for MmWave Communication System

TL;DR

This paper introduces an enhanced mmWave sensing method capable of accurately detecting targets in non-line-of-sight environments by leveraging reflection paths and geometric transformations, improving robustness over existing LoS-dependent techniques.

Contribution

The paper proposes a novel 3D NLoS sensing algorithm (mm3NLoS) that accurately estimates target position using reflection paths, addressing limitations of prior LoS-focused methods.

Findings

Achieves centimeter-level accuracy in simulations

Significantly reduces performance degradation in NLoS conditions

Effectively estimates target direction and distance in complex environments

Abstract

The millimeter-wave (mmWave)-based Wi-Fi sensing technology has recently attracted extensive attention since it provides a possibility to realize higher sensing accuracy. However, current works mainly concentrate on sensing scenarios where the line-of-sight (LoS) path exists, which significantly limits their applications. To address the problem, we propose an enhanced mmWave sensing algorithm in the 3D non-line-of-sight environment (mm3NLoS), aiming to sense the direction and distance of the target when the LoS path is weak or blocked. Specifically, we first adopt the directional beam to estimate the azimuth/elevation angle of arrival (AoA) and angle of departure (AoD) of the reflection path. Then, the distance of the related path is measured by the fine timing measurement protocol. Finally, we transform the AoA and AoD of the multiple non-line-of-sight (NLoS) paths into the direction vector and then obtain the information of targets based on the geometric relationship. The simulation results demonstrate that mm3NLoS can achieve a centimeter-level error with a 2m spacing. Compared to the prior work, it can significantly reduce the performance degradation under the NLoS condition.