The principle of backscattering has the potential to enable a full realization of the Internet of Things. This paradigm subsumes massively deployed things that have the capability to communicate directly with each other. Based on the types of excitation and receivers, we discriminate four types of backscattering systems: (i) Dedicated Exciter Active Receiver systems, (ii) Ambient Exciter Active Receiver systems, (iii) Dedicated Exciter Passive Receiver systems, and (iv) Ambient Exciter Passive Receiver systems. In this paper, we present an overview of bacskscattering systems with passive receivers which form the foundation for Backscattering Tag-to-Tag Networks (BTTNs). This is a technology that allows tiny batteryless RF tags attached to various objects to communicate directly with each other and to perform RF-based sensing of the communication link. We present an overview of recent innovations in hardware architectures for backscatter modulation, passive demodulation, and energy harvesting that overcome design challenges for passive tag-to-tag communication. We further describe the challenges in scaling up the architecture from a single link to a distributed network. We provide some examples of application scenarios enabled by BTTNs involving object-to-object communication and inter-object or human-object dynamic interactions. Finally, we discuss key challenges in present-day BTTN technology and future research directions.
Receiver Selectivity Limits on Bistatic Backscatter Range
Backscatter communication has been a popular choice in low-power/battery-free sensor nodes development. However, the effect of RF source to receiver distance on the operating range of this communication system has not been modeled accurately. In this paper, we propose a model for a bistatic backscatter system coverage map based on the receiver selectivity, receiver sensitivity, and geometric placement of the receiver, RF source, and the tag. To verify our proposed model and simulations, we perform an experiment using a low-cost commercial BLE receiver and a custom-designed BLE backscatter tag. We also show that the receiver selectivity might depend on the interference level, and present measurement results to signify how this dependence relates the system bit error rate to the RF excitation power.
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- 2020 IEEE International Conference on RFID (RFID)
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- 1 to 8
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- National Science Foundation
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