RF-Chord: Towards Deployable RFID Localization System for Logistic Networks

RFID localization is considered the key enabler of automating the process of inventory tracking and management for the high-performance logistic network. A practical and deployable RFID localization system needs to meet reliability, throughput, and range requirements. This paper presents RF-CHORD, the first RFID localization system that simultaneously meets all three requirements. RF-CHORD features a multisine-constructed wideband design that can process RF signals with a 200 MHz bandwidth in real-time to facilitate one-shot localization at scale. In addition, multiple SINR enhancement techniques are designed for range extension. On top of that, a kernel-layer near-field localization framework and a multipath-suppression algorithm are proposed to reduce the 99th long-tail errors. Our empirical results show that RF-CHORD can localize up to 180 tags 6 m away from a reader within 1 second and with 99th longtail error of 0.786 m, achieving a 0% miss reading rate and ~0.01% cross-reading rate in the warehouse and fresh food delivery store deployment.