DEVICE, SYSTEM AND METHOD FOR COMPENSATING SIGNAL DELAYS IN AN RFID COMMUNICATION SYSTEM

• US 20100007467A1
• Filed: 09/27/2007
• Published: 01/14/2010
• Est. Priority Date: 10/12/2006
• Status: Active Grant

• Current Assignee: Quotainne Enterprises LLC
• Original Assignee: NXP B.V. (NXP Semiconductors NV)
• Inventors: Thueringer, Peter, Breitfuss, Klemens
• Granted Patent: US 8,203,430 B2
• Time in Patent Office: Days
• US Class Current: 340/10.100
• 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 7/10237 the reader and the record carrier being capable of selectively switching between reader and record carrier appearance, e.g. in near field communication [NFC] devices where the NFC device may function as an RFID reader or as an RFID tag
• 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

Abstract

An RFID communication system comprises an NFC device (11) and a smart card (2) with contactless card functionality, wherein the NFC device (11) and the smart card (2) are couplable to each other via a protocol converter (7), wherein the NFC device (11) is coupled to an antenna (3) to receive electromagnetic signals (ES) from an RFID reader/writer and to transmit response signals (RS) to the RFID reader/writer by modulating received electromagnetic signals (ES). The electromagnetic signals (ES) contain first and second characteristic components (FE, RE) which define the begin and the end of a predefined signal pattern (PA), wherein the second characteristic component triggers a predefined response delay time (FDT) at the expiration of which the RFID communication system has to respond to the RFID reader/writer. A device (12) for compensating signal delays is provided that comprises signal pattern shortening means (13).

Claims

1. A device for compensating signal delays in an RFID communication system, the device comprising:

an NFC device coupled to an antenna to receive electromagnetic signals from an RFID reader/writer and to transmit response signals to the RFID reader/writer by modulating received electromagnetic signals, wherein the electromagnetic signals contain first and second characteristic components which define the begin and the end of a predefined signal pattern, wherein the second characteristic component triggers a predefined response delay time at the expiration of which the RFID communication system responds to the RFID reader/writer, wherein the device for compensating signal delays includes a signal pattern shortening signal; and

a smart card with contactless card functionality, wherein the NFC device and the smart card are coupled to each other via a protocol converter.

2. The device according to claim 1, wherein when the first characteristic component of the signal pattern and a square-wave signal generator is detected, the signal generator is stopped from outputting signals, and wherein the signal generator starts to output signals again after a predefined shortened signal pattern time.

3. The device according to claim 2, wherein the electromagnetic signals transmitted by the RFID reader/writer include a carrier signal that is modulated by a data signal wherein the frequency of the output signals generated by the signal generator is equal to the frequency of the carrier signal.

4. The device according to claim 1, wherein the first and second characteristic components of the signal pattern are falling or rising signal edges.

5. The device according to claim 1, wherein the predefined signal pattern is a signal pause pattern.

6. The device according to claim 1, further comprising a response delay that is adapted to delay a response from the smart card by an additional delay time.

7. The device according to claim 6, wherein the additional delay time is adjustable by the response delay.

8. The device according to claim 7, wherein the response delay is adapted to adjust the additional delay time such that a response signal is delayed until the response delay time counted from the occurrence of the second characteristic component has expired.

9. An RFID communication system, comprising:

an NFC device coupled to an antenna to receive electromagnetic signals from an RFID reader/writer and to transmit response signals to the RFID reader/writer by modulating received electromagnetic signals, wherein the electromagnetic signals contain first and second characteristic components which define the begin and the end of a predefined signal pattern, wherein the second characteristic component triggers a response delay time at the expiration of which the RFID communication system responds to the RFID reader/writer;

a device for compensating signal delays that includes a signal pattern shortening signal; and

a smart card with contactless card functionality, wherein the NFC device and the smart card are coupled to each other via a protocol converter.

10. The RFID communication system according to claim 9, wherein the system complies with ISO 14443.

11. A method for compensating signal delays in an RFID communication system, the method comprising:

receiving electromagnetic signals from an RFID reader/writer by an NFC device coupled to an antenna;

transmiting response signals to the RFID reader/writer by the NFC device by modulating the received electromagnetic signals, wherein the electromagnetic signals contain first and second characteristic components which define the begin and the end of a predefined signal pattern;

triggering a predefined response delay time by the second characteristic component at the expiration of which the RFID communication system responds to the RFID reader/writer, wherein a device for compensating signal delays includes a signal pattern shortening signal.

12. The method according to claim 11, further comprising:

detecting the first characteristic component; and

stopping a square-wave signal generator from generating signals when the first characteristic component is detected so that the signal pattern is shortened; and

restarting the square-wave signal generator to output signals after a predetermined shortened signal pattern time after the detection of the first characteristic component.

13. The method according to claim 12, wherein the electromagnetic signals received from the RFID reader/writer includes a carrier signal that is modulated by a data signal wherein the frequency of the signals generated by the signal generator are equal to the frequency of the carrier signal.

14. The method according to claim 11, wherein the first and second characteristic components of the signal pattern are falling or rising signal edges.

15. The method according to claim 11, wherein the predefined signal pattern is a signal pause pattern.

16. The method according to claim 11, further comprising delaying a response from the smart card by an additional delay time.

17. The method according to claim 16, wherein the additional delay time is adjusted in operation.

18. The method according to claim 17, wherein the additional delay time is adjusted such that a response signal is delayed until the response delay time counted from the occurrence of the second characteristic component has expired.