Backscattering type RFID communication system

摘要

A backscattering type radio frequency identification (RFID) communication system, and more particularly, a backscattering type RFID communication system in which an RFID tag transmits a signal back to an RF reader by using energy of a carrier wave transmitted by the RFID reader. Provided is a backscattering type radio frequency identification (RFID) communication system RFID communications are performed efficiently without an error while interference between RFID readers does not occur even under an overcrowded reader environment. Interference of RF signals between the RFID readers does not occur, and RFID communications can be efficiently performed even under the overcrowded reader environment. Transmitting and receiving time steps of the RFID readers do not need to be synchronized with one another so that compatibility of the RFID readers can be improved.

主权项

1. A backscattering type radio frequency (RFID) communication system comprising:
a plurality of RFID readers, each of the plurality of RFID readers comprising: a reader controller generating a query signal to be transmitted to an RFID tag; a visible ray transmitting unit transmitting the query signal transmitted by the reader controller in a form of visible rays; a reader transmitter continuously transmitting a non-modulated carrier wave of a precise frequency having no bandwidth in a form of RF by selecting one from among a plurality of frequency channels; and a reader receiver receiving a response signal in a form of RF transmitted from the RFID tag and transmitting the response signal to the reader controller, wherein transmitting and receiving of the query signal and transmitting and receiving of the response signal are performed by dividing visible rays and RF signals, the number of the RFID readers is greater than the number of frequency channels; and a plurality of RFID tags, each of the plurality of RFID tags comprising: a visible ray receiving unit receiving the query signal transmitted by the visible ray transmitting unit of the RFID reader and converting the query signal into an electrical signal; a tag receiver receiving the non-modulated carrier wave continuously transmitted by the reader transmitter of the RFID reader; a tag controller processing a command of the query signal received by the visible ray receiving unit and generating the response signal with respect to the query signal; and a tag transmitter transmitting the response signal transmitted by the tag controller in a form of an RF carrier signal with respect to the non-modulated carrier wave by using energy of the non-modulated carrier wave received by the tag receiver.