RFID-based indoor location systems have been proved to be both accurate and cost-effective. However, current implementations mainly use active tags which suffer the issues of batteries replacement, installation, maintenance and per-unit cost. Besides, as the number of users grows, how to guarantee the stability and high speed transmission of the location information can be challenging. To address these challenges, 1) we propose a passive RFID-based system for localizing multi-users, and 2) detecting human motion from various types of embedded sensors to be supplemented. In addition, we also implement a reliable transmission protocol to guarantee the location data transition between RF nodes based on dynamic PRI. According to the performance analysis, the tracking accuracy of our system is well assured. Its quick responsiveness and good scalability, as well as low cost on energy and infrastructure, make this system a more cost-effective and easy-to-deploy solution for stable indoor positioning.
