mmMirror: Device Free mmWave Indoor NLoS Localization Using Van-Atta-Array IRS

TL;DR

mmMirror introduces a device-free mmWave localization system using a Van Atta Array IRS to achieve precise NLoS indoor positioning, enhancing safety and interaction in industrial environments.

Contribution

The paper presents mmMirror, a novel IRS-based mmWave system that improves NLoS localization accuracy and range, integrating seamlessly with existing radars and supporting multi-target scenarios.

Findings

Centimeter-level accuracy at up to 3 meters range

Seamless communication between radar and IRS

Supports multi-radar and multi-target localization

Abstract

Industry 4.0 is transforming manufacturing and logistics by integrating robots into shared human environments, such as factories, warehouses, and healthcare facilities. However, the risk of human-robot collisions, especially in Non-Line-of-Sight (NLoS) scenarios like around corners, remains a critical challenge. Existing solutions, such as vision-based and LiDAR systems, often fail under occlusion, lighting constraints, or privacy concerns, while RF-based systems are limited by range and accuracy. To address these limitations, we propose mmMirror, a novel system leveraging a Van Atta Array-based millimeter-wave (mmWave) reconfigurable intelligent reflecting surface (IRS) for precise, device-free NLoS localization. mmMirror integrates seamlessly with existing frequency-modulated continuous-wave (FMCW) radars and offers: (i) robust NLoS localization with centimeter-level accuracy at ranges up to 3 m, (ii) seamless uplink and downlink communication between radar and IRS, (iii) support for multi-radar and multi-target scenarios via dynamic beam steering, and (iv) reduced scanning latency through adaptive time slot allocation. Implemented using commodity 24 GHz radars and a PCB-based IRS prototype, mmMirror demonstrates its potential in enabling safe human-robot interactions in dynamic and complex environments.