UNIQC: Unified I/Q Correction with Quality-Scored Filtering for BLE-Enabled Application Traceability for Industry 4.0 Applications

Industry 4.0 has catalyzed resource allocation, merging high-precision traceability to streamline production and minimize wastage. Within the industrial context, real-time tracking assets enhances operational efficiency and diminishes energy expenditure by alleviating logistical inefficiencies. Although Global Positioning System demonstrates robustness for outdoor localization, indoor positioning systems (IPS) frequently exhibit suboptimal performance. The advent of Bluetooth Low Energy (BLE) v5.1, leveraging angle of arrival (AoA), delivers a cost-efficient, precise framework for traceability in industrial indoor environments. Prevailing research primarily emphasizes on exploiting the collected signals to estimate angles for indoor localization. However, little attention is paid to signal quality, particularly affected by complex industrial environment, which may markedly degrade the positioning performance. Specifically, imbalances between in-phase (I) and quadrature (Q) signal components impair received signal quality, ultimately undermining positioning accuracy. To address this challenge, this article proposes UNIQC for BLE AoA-enabled IPS, incorporating unified I/Q correction with quality-scored filtering to elevate precision and reduce computational load. An onsite experiment validates its efficacy, evidencing enhanced filtering and superior angle estimation for resource traceability in Industry 4.0.