Cdma-Rfid
First Claim
1. An RF tag, comprising:
- a receiver for interrogator signal, which receives a signal from an interrogator;
a generator for synchronization signal, which generates a synchronization signal based on the interrogator signal received by said receiver for interrogator signal;
an acquirer for response information, which acquires response information based on the interrogator signal received by said receiver for interrogator signal;
a spread-code modulator, which acquires spread-code modulated response information by spread-code modulating the response information acquired by said acquirer for response information; and
a transmitter, which transmits a response signal, which includes the spread-code modulated response information as data area acquired by said spread-code modulator, based on the synchronization signal generated by said generator for synchronization signal at random transmission interval.
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Accused Products
Abstract
If a total number of specific RF tags is too large, many RF tags respond at a time. Therefore a problem occurs that an interrogator cannot receive information from the RF tags. A first invention relates to an RF tag. The RF tag includes an interrogator signal receiving section for receiving an interrogator signal from an interrogator, a synchronizing signal generating section for generating a synchronizing signal from the received interrogator signal, a response information obtaining section for obtaining response information according to the interrogator signal, a spread-code modulating section for modulating the response information with a spreading code and obtaining the spread-code modulated response information, and a transmitting section for transmitting the response signal that contains the spread-code modulated response information in a data area at a random transmission interval in synchronism with the synchronizing signal.
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Citations
28 Claims
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1. An RF tag, comprising:
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a receiver for interrogator signal, which receives a signal from an interrogator;
a generator for synchronization signal, which generates a synchronization signal based on the interrogator signal received by said receiver for interrogator signal;
an acquirer for response information, which acquires response information based on the interrogator signal received by said receiver for interrogator signal;
a spread-code modulator, which acquires spread-code modulated response information by spread-code modulating the response information acquired by said acquirer for response information; and
a transmitter, which transmits a response signal, which includes the spread-code modulated response information as data area acquired by said spread-code modulator, based on the synchronization signal generated by said generator for synchronization signal at random transmission interval. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 28)
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18. An interrogator, comprising:
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an acquirer for interrogator signal, which acquires a interrogator signal;
a transmitter for interrogator signal, which transmits the interrogator signal acquired by the acquirer for interrogator signal;
an acquirer for synchronization signal, which acquires a synchronization signal correlated with said interrogator signal; and
a receiver for response signal, which receives a response signal from RF tag to the interrogator signal transmitted from said transmitter for interrogator signal on the basis of the synchronization signal acquired by said acquirer for synchronization signal. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27)
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Specification