Reader device, its transmission method, and tag

• US 20050280509A1
• Filed: 01/26/2005
• Published: 12/22/2005
• Est. Priority Date: 06/17/2004
• Status: Abandoned Application

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Gotoh, Kunihiko, Yamazaki, Daisuke, Tanaka, Yoshinori
• Application Number:
  US11/042,440
• Publication Number:
  US 20050280509A1
• Time in Patent Office: Days
• US Class Current: 340/10.3
• CPC Class Codes: G01S 13/758 using a signal generator powered by the interrogation signal
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10297 arrangements for handling protocols designed for non-contact record carriers such as RFIDs NFCs, e.g. ISO/IEC 14443 and 18092 cryptographic protocols H04L9/00; network security protocols H04L63/00; real-time communication protocols in data switching networks H04L65/00; network protocols for data switching network services H04L67/00
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A reader device and RF tag improves the efficiency of frequency usage without increasing bandwidth using wireless communication from the reader to the tag and provides a transmission method that improves the power supply efficiency from the reader to the tag to extend the communication distance from the tag to the reader. A reader device for wirelessly communicating with an RF tag, comprises circuitry operable to transmit a wireless signal including information indicating encoding method of data to the RF tag and circuitry operable to receive and demodulate a wireless signal from the RF tag.

Claims

1. A reader device for wirelessly communicating with an RF tag, comprising:

circuitry operable to transmit a wireless signal including information indicating coding method used to the RF tag; and

circuitry operable to receive and demodulate a wireless signal from the RF tag.

2. The reader device of claim 1, further comprising:

circuitry operable to each symbol with same peak level of encoded signals;

circuitry operable to transmit signals of varying amplitudes of each symbol; and

circuitry operable to demodulate the signal from the tag.

3. The reader device of claim 2, wherein encoding modulation is N-bit Manchester Encoding, wherein N is at least 2.

6. The reader device of claim 1, further comprising:

circuitry operable to offset and transmit constant peak values of each symbol'"'"'s multi-level signals.

7. The reader device of claim 6, wherein the encoding modulation is Manchester Encoding Amplitude Modulation.

4. A transmission method comprising:

generating a signal with information indicating the encoding method; and

modulating the generated signal.

5. The transmission method of claim 4, further comprising:

generating a preamble pattern signal and a signal indicating a encoding method of data; and

outputting a transmission data which have a data attaching the preamble pattern signal and the signal indicating an encoding method of data.

8. An RF tag for wirelessly communicating with a reader device, comprising:

circuitry operable to receive modulated signals attached with information identifying encoding method of Manchester code before modulation;

circuitry operable to detect demodulation procedures and information to identify the corresponding encoding method; and

circuitry operable to switch the demodulation process in response to the information identifying the encoding method.