1 research outputs found
A Handheld Fine-Grained RFID Localization System with Complex-Controlled Polarization
There is much interest in fine-grained RFID localization systems. Existing
systems for accurate localization typically require infrastructure, either in
the form of extensive reference tags or many antennas (e.g., antenna arrays) to
localize RFID tags within their radio range. Yet, there remains a need for
fine-grained RFID localization solutions that are in a compact, portable,
mobile form, that can be held by users as they walk around areas to map them,
such as in retail stores, warehouses, or manufacturing plants.
We present the design, implementation, and evaluation of POLAR, a portable
handheld system for fine-grained RFID localization. Our design introduces two
key innovations that enable robust, accurate, and real-time localization of
RFID tags. The first is complex-controlled polarization (CCP), a mechanism for
localizing RFIDs at all orientations through software-controlled polarization
of two linearly polarized antennas. The second is joint tag discovery and
localization (JTDL), a method for simultaneously localizing and reading tags
with zero-overhead regardless of tag orientation. Building on these two
techniques, we develop an end-to-end handheld system that addresses a number of
practical challenges in self-interference, efficient inventorying, and
self-localization. Our evaluation demonstrates that POLAR achieves a median
accuracy of a few centimeters in each of the x/y/z dimensions in practical
indoor environments