Patent ID: 11971473
Assignee: NEC CORPORATION
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 8:
9. A product locating method, comprising:
emitting, by at least one Radio Frequency (RF) backscatter transmitter, a main carrier RF signal that forms an excitation signal;
generating, by a passive RF backscatter tag associated with a product, an Ultra-Wideband (UWB) signal from the excitation signal; and
simultaneously receiving, by at least one RF backscatter receiver, both the excitation signal from the at least one RF backscatter transmitter and the UWB signal from the passive RF backscatter tag, and computing a time-difference-of-arrival (TDoA) therebetween;
wherein TDoA information from multiple RF backscatter receivers, including the at least one RF backscatter receiver, is aggregated to compute the location of the product to which the passive RF backscatter tag is attached; and
wherein different RF backscatter transmitters send an excitation signal at different times to activate passive RF backscatter tags in different regions of deployment; and further comprising:
sending, by the at least one RF backscatter transmitter, a harvesting signal used for energy harvesting by the passive RF backscatter tag; and
sending, by the at least one RF backscatter transmitter a backscatter signal to initiate tag transmission.