Passive UWB RFID for Tag Localization: Architectures and Design

Abstract

International audienceIn the new scenarios foreseen by the Internet of Things, industrial and commercial systems will be required to detect and localize tagged items with high accuracy, as well as to monitor the level of certain parameters of interest through the deployment of wireless sensors. To meet these challenging requirements, the adoption of passive and semi-passive ultra-wideband (UWB) radio-frequency identification (RFID) appears a promising solution which overcomes the limitations of standard Gen.2 ultra-high frequency (UHF) RFID. The design and implementation of such systems pose several practical constraints, impacting the overall network architecture. In this paper, the main issues and challenging aspects for the design of a UWB-RFID network considering architectural and protocol choices are discussed in a unitary framework, and practical solutions, accounting for the presented issues, are proposed. Moreover, the possible integration of UWB-RFID with standard Gen.2 UHF-RFID is proposed as an interesting option, discussing architectural solutions, their advantages and drawbacks

RFID Tag as a Sensor - A Review on the Innovative Designs and Applications

“…The final location of target is estimated by using the RSSI relationship between the target tag and candidate reference tags. The system design of a UWB-RFID network for tag localisation in IoT applications is presented in [80], and it is found that the architectural choice is strictly application dependent, and must account for costs, complexity, energy efficiency, backward compatibility and performance. It is evident that the architecture design is significant to the success of an RFID sensor network application.…”

The future of ultra-wideband localization in RFID

“…The main consequence is that tags are completely asynchronous. This problem can be solved by a proper design of the code and the introduction of side synchronization signals (e.g., in the UHF band) to provide a coarse synchronization, as it will be explained later [26]. To facilitate code acquisition at the receiver in [24] (quasi)-orthogonal codes allowing multiple tags operating simultaneously with limited reciprocal interference have been investigated.…”

“…Due to the impossibility to extract significant energy from the UWB link because of regulatory issues, a solution is to exploit the UHF band to transfer the required energy to the tag as done in Gen.2 RFID [26].…”

“…In the context of the Italian project GRETA, the energy efficiency and eco-compatibility aspects of UWB-RFID systems have been investigated [26], [27]. Coexisting UHF and UWB interrogation signals have been considered to transfer the energy to the tag and provide some synchronization reference.…”

“…The synchronization signal can be obtained by modulating the amplitude of the UHF carrier with a periodic square wave having period T c which timing is extracted by the clock extractor and used to drive the code generator. A simpler alternative method is to synchronize the code generator at the falling edge of the UHF wake-up signal [26]. In this case a local clock generator must be included in the tag and clock drifts have to be properly managed at the reader.…”