Method and Apparatus Adapted to Demodulate a Data Signal

• US 20080267331A1
• Filed: 09/08/2006
• Published: 10/30/2008
• Est. Priority Date: 09/12/2005
• Status: Active Grant

• Current Assignee: SATO Holdings Corporation
• Original Assignee: Magellan Technology Pty. Ltd (SATO Holdings Corporation)
• Inventors: Littlechild, Stuart Colin, Murdoch, Graham Alexander Munro
• Granted Patent: US 8,451,950 B2
• Time in Patent Office: Days
• US Class Current: 375/371
• 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: H03D 1/24 for demodulation of signals wherein one sideband or the carrier has been wholly or partially suppressed receiver circuits H04B1/302
• CPC Class Codes: H03D 3/02 by detecting phase difference between two signals obtained from input signal H03D3/28 - H03D3/32 take precedence; muting in frequency-modulation receivers H03G3/28; limiting arrangements H03G11/00
• CPC Class Codes: H03L 7/0812 and where no voltage or current controlled oscillator is used
• CPC Class Codes: H03L 7/0816 the controlled phase shifter and the frequency- or phase-detection arrangement being connected to a common input
• CPC Class Codes: H04L 25/4902 Pulse width modulation; Pulse position modulation
• CPC Class Codes: H04L 27/2331 wherein the received signal is demodulated using one or more delayed versions of itself

Abstract

The present invention relates to the field of receiving data and/or demodulating a data transmission signal. The present invention provides a method of and/or device for determining a data signal imposed on a phase jitter modulation signal. In one form, the invention relates to the field of Radio Frequency Identification (RFID), and the transmission of data between a tag and an interrogator.

Claims

1. A method of determining a data signal imposed on a phase jitter modulation (PJM) signal, the method comprising the steps of:

providing a first phase jitter modulated signal;

applying a delay to the first phase jitter modulated signal, and obtaining a second signal;

comparing the first and second signals;

determining a phase difference between the first and second signals; and

reconstructing a data signal based on the phase difference.

2. The method as claimed in claim 1, wherein the delay is a variable delay.

3. The method as claimed in claim 1, wherein the phase difference is determined by an XOR gate.

4. The method as claimed in claim 1, wherein the phase difference is determined by a mixer.

5. The method as claimed in claim 1, wherein the phase difference is determined by a multiplier.

6. The method as claimed in claim 1, wherein the phase difference is determined by a digital vernier circuit.

7. The method as claimed in claim 1, wherein the delay is less than half of a bit period.

8. The method as claimed in claim 1, wherein the delay is less than one quarter of a bit period.

9. The method as claimed in claim 1, wherein the method is applied in an RFID system.

10. A device adapted to demodulate a data signal imposed on a phase jitter modulation (PJM) signal, comprising:

a receiver adapted to receiver a first phase jitter modulated signal;

delay means adapted to delay the first phase jitter modulated signal, and obtaining a second signal; and

logic means adapted to compare the first and second signals, determine a phase difference between the first and second signals, and reconstructing a data signal based on the phase difference.

11. The device as claimed in claim 10, wherein the delay is a variable delay.

12. The device as claimed in claim 10, wherein the phase difference is determined by an XOR gate.

13. The device as claimed in claim 10, wherein the phase difference is determined by a mixer.

14. The device as claimed in claim 10, wherein the phase difference is determined by a multiplier.

15. The device as claimed in claim 10, wherein the phase difference is determined by a digital vernier circuit.

16. The A device as claimed in claim 10, wherein the delay is less than half of a bit period.

17. The device as claimed in claim 10, wherein the delay is less than one quarter of a bit period.

18. The A device as claimed in claim 10, wherein the device is an RFID device.

19. The A device as claimed in claim 18, wherein the device being a tag, transponder or interrogator.

20. A RFID system including a W device, the device adapted to demodulate a data signal imposed on a phase jitter modulation (PJM) signal the device comprising:

a receiver adapted to receiver a first phase jitter modulated signal;

delay means adapted to delay the first phase jitter modulated signal, and obtaining a second signal; and

logic means adapted to compare the first and second signals, determine a phase difference between the first and second signals, and reconstructing a data signal based on the phase difference.

21-22. -22. (canceled)