Joint Visible Light and Backscatter Communications for Proximity-Based Indoor Asset Tracking Enabled by Energy-Neutral Devices

2025-10-31

AI Summary

To address the challenge of simultaneously achieving low-power localization and sustainable operation for energy-autonomous IoT devices in next-generation wireless systems, this paper proposes an indoor asset tracking system integrating visible light communication (VLC) and passive backscatter. The system leverages LED access points to concurrently transmit data and energy, enabling battery-free terminal localization in multi-cell environments. To mitigate multiple-access interference, it introduces a novel four-color spectral scheduling scheme based on frequency-division multiplexing. At the edge, proximity reports and received signal strength are fused and processed via a lightweight particle filter for efficient tracking. Experimental evaluation across multiple indoor trajectories demonstrates median and 90th-percentile localization accuracies of 0.318 m and 0.634 m, respectively—substantially improving robustness and scalability over prior approaches.

Technology Category

• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Intelligent Robots: Localization, Mapping, and Navigation
• Computer Vision: Motion & Tracking

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• Security and Privacy: Tracking, profiling, and countermeasures against them
• User Modeling, Personalization and Recommendation: On-Device user modeling, personalization, and recommendation

Abstract

In next-generation wireless systems, providing location-based mobile computing services for energy-neutral devices has become a crucial objective for the provision of sustainable Internet of Things (IoT). Visible light positioning (VLP) has gained great research attention as a complementary method to radio frequency (RF) solutions since it can leverage ubiquitous lighting infrastructure. However, conventional VLP receivers often rely on photodetectors or cameras that are power-hungry, complex, and expensive. To address this challenge, we propose a hybrid indoor asset tracking system that integrates visible light communication (VLC) and backscatter communication (BC) within a simultaneous lightwave information and power transfer (SLIPT) framework. We design a low-complexity and energy-neutral IoT node, namely backscatter device (BD) which harvests energy from light-emitting diode (LED) access points, and then modulates and reflects ambient RF carriers to indicate its location within particular VLC cells. We present a multi-cell VLC deployment with frequency division multiplexing (FDM) method that mitigates interference among LED access points by assigning them distinct frequency pairs based on a four-color map scheduling principle. We develop a lightweight particle filter (PF) tracking algorithm at an edge RF reader, where the fusion of proximity reports and the received backscatter signal strength are employed to track the BD. Experimental results show that this approach achieves the positioning error of 0.318 m at 50th percentile and 0.634 m at 90th percentile, while avoiding the use of complex photodetectors and active RF synthesizing components at the energy-neutral IoT node. By demonstrating robust performance in multiple indoor trajectories, the proposed solution enables scalable, cost-effective, and energy-neutral indoor tracking for pervasive and edge-assisted IoT applications.

Problem

• Develops energy-neutral indoor asset tracking using visible light and backscatter communication
• Eliminates power-hungry photodetectors through hybrid visible light and RF backscatter system
• Achieves sub-meter positioning accuracy while maintaining device energy neutrality

Innovation

• Hybrid visible light and backscatter communication system
• Energy-neutral nodes harvesting power from LEDs
• Lightweight particle filter algorithm for location tracking