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RFID carrier wave interception method and RFID system adopting the same

A technology of continuous carrier wave and polarization direction, which is applied in the directions of near-field transmission systems of transceivers, cooperating devices, instruments, etc., which can solve the problems of long waiting time and short communication time.

Inactive Publication Date: 2008-01-23
FUJITSU LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0014] The former method, following the flow of Figure 2, involves performing carrier sense as described above to search for channels not currently being used by other readers / writers and use the free channel if one exists The method faces the problem that there is a large number of readers / writers and the waiting time is long
Furthermore, in the case of the latter method involving centralized control by means of a control device, when there are a large number of readers / writers, there is a problem that the allocated communication time is short

Method used

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  • RFID carrier wave interception method and RFID system adopting the same
  • RFID carrier wave interception method and RFID system adopting the same
  • RFID carrier wave interception method and RFID system adopting the same

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Embodiment Construction

[0039] Embodiments of the present invention will be described below based on the accompanying drawings. The embodiments described below enable the present invention to be understood, and the technical scope of the present invention is not limited thereto.

[0040] Fig. 4 shows a situation where a plurality of readers / writers #1 and #2 operate adjacent to each other so as to become an RFID system, and compared with Fig. 1, when carrier sensing is a feature of the present invention, providing Function 4 to control the polarization direction of the antenna 1b of the reader / writer.

[0041] FIG. 5 is a conceptual diagram of a configuration example of readers / writers #1 and #2 to which the present invention is applied.

[0042] In FIG. 5 , an antenna 1 b includes an antenna element 10 and a polarization direction control unit 20 . The polarization direction control section 20 shown in FIG. 5 has a function of switching the polarization direction of the antenna element 10 to right...

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PUM

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Abstract

There is provided a RFID system capable of increasing the probability to detect an empty channel and reduce the affect of the interference between readers / writers. The RFID system includes: a reader / writer having a reader / writer main body and an antenna capable of switching polarization for transmitting a continuous carrier; and a tag for modulating the continuous carrier by tag information and returning a response signal to the reader / writer. The reader / writer main body judges the level of the interference signal received, decides the channel and the polarization direction for making the interference signal level below a threshold value, and receives the response signal from the tag by the decided channel and the polarization direction.

Description

technical field [0001] The present invention relates to a radio frequency ID (RFID: Radio Frequency Identification) carrier sense method, and an RFID reader / writer and RFID system using radio frequency ID. Background technique [0002] In recent years, in terms of reading ID information recorded on a tag, a system that uses magnetic coupling with a tag to read or an RFID system that uses a radio frequency to read tag information has been developed and used. [0003] As for the latter RFID system for reading using a radio frequency, as an example, ETSI (European Telecommunications Standards Institute) (Draft ETSI EN 302 208-1 V1.1.1 (2003-12)) has published a European standard. In Draft ETSI EN 302 208-1 V1.1.1 (2003-12) the use of RFID systems with a maximum power of 2W utilizing the 865MHz to 868MHz frequency band is disclosed. [0004] Here, there are cases where a plurality of readers / writers operate adjacent to each other to become an RFID system. Figure 1 shows an exa...

Claims

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Application Information

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IPC IPC(8): H04B5/02G06K17/00
Inventor 田中良纪
Owner FUJITSU LTD