Philip Stewart Royston

• US 20120077434A1
• Filed: 09/29/2011
• Published: 03/29/2012
• Est. Priority Date: 09/29/2010
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: ROYSTON, Philip Stewart
• Granted Patent: US 8,693,949 B2
• Time in Patent Office: Days
• US Class Current: 455/41.1
• CPC Class Codes: H04W 74/06 using polling
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 84/10 Small scale networks; Flat hierarchical networks
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A near-field RF communicator which is operable to perform a polling process to initiate communication with another near-field RF communicator in near-field range, wherein the near-field communicator is configured to perform a detection process, having a lower energy requirement than a polling process, to determine whether a near-field RF communicator is present in near-field range, and to perform the polling process in the event that the detection process indicates that a near-field RF communicator is present in near-field range.

Claims

1. A method of operating a near-field radio frequency (RF) communicator, comprising:

transmitting a RF signal;

comparing at least one measure of in-phase and quadrature-phase components of a signal in an inductive coupler that is disposed in the near-field RF communicator with at least one stored value; and

determining whether to initiate polling for another near-field RF communicator based on the comparison.

2. The method of claim 1, further comprising:

storing at least one value based on the at least one measure of the in-phase and quadrature-phase components in a memory to provide at least one stored value for a subsequent comparison.

3. The method of claim 1, wherein the at least one measure of the in-phase and quadratare-phase components comprises a first indication of the in-phase component and a second indication of the quadrature-phase component.

4. The method of claim 3, wherein the stored value comprises a first stored value indicating the in-phase component and a second stored value indicating the quadrature-phase component.

5. The method of claim 4, further comprising:

determining a first difference between the first indication and the first stored value and determining a second difference between the second indication and the second stored value.

6. The method of claim 5, further comprising:

comparing the first difference with a first threshold value and comparing the second difference with a second threshold value; and

initiating polling for another near-field RF communicator in the event that either;

the first difference exceeds the first threshold value, or the second difference exceeds the second threshold value.

7. The method of claim 5, further comprising:

determining a square of the first difference and determining a square of the second difference to provide an indication of a magnitude of change from the stored value.

8. The method of claim 7, further comprising:

comparing the indication of the magnitude with a threshold value.

9. The method of claim 3, further comprising:

determining a phase value based on the first and the second indications; and

comparing the phase value with a stored phase value.

10. The method of claim 1, further comprising:

initiating a polling procedure.

11. The method of claim 10, further comprising:

initiating the polling procedure at intervals regardless of whether the comparing and determining steps indicate the presence of another near-field communicator in near-field range;

wherein the polling procedure is initiated periodically or intermittently.

12. A near-field radio frequency (RF) communicator, comprising:

an inductive coupler configured to inductively couple with a magnetic field (H-field);

a signal provider, coupled to the inductive coupler, configured to transmit a signal;

a signal characteristic determiner, coupled to the inductive coupler, configured to determine a signal characteristic, the signal characteristic indicative of a change in an apparent complex impedance of the inductive coupler; and

a controller configured to perform a comparison between the signal characteristic and a stored value to indicate a presence of another near-field RF communicator and to initiate a polling procedure based on the comparison.

13. The near-field RF communicator of claim 12, wherein the signal characteristic determiner is further configured to determine a first phase component of the signal and a second phase component of the signal, wherein the first phase component and the second phase component are not in phase.

14. The near-field RF communicator of claim 13, wherein the signal characteristic determiner comprises an IQ mixer.

15. A method of operating an electronic device, comprising:

(a) determining, by a first near-field RF communicator, whether a second near-field RF communicator is present within near-field range of the first near-field RF communicator; and

(b) performing, by the first near-field RF communicator, if the determination of step (a) is affirmative, a polling process to initiate communication with the second near-field RF communicator;

wherein step (a) takes less time than step (b).

16. The method of claim 16, wherein the polling process comprises:

transmitting a wake-up signal to initiate communication with the second near-field RF communicator.

17. The method of claim 16, wherein the polling process comprises:

transmitting a plurality of wake-up signals in a sequence, each wake-up signal of the plurality of wake-up signals being adapted to initiate communication with a particular type of near-field RF communicator.

18. The method of claim 16, wherein the first near-field RF communicator includes an inductive coupler;

and wherein step (a) comprises;

detecting in-phase and quadrature-phase components of a voltage in the inductive coupler; and

comparing at least one measure of the in-phase and quadrature-phase components of a signal in the inductive coupler with at least one stored value.

19. The method of claim 18, wherein step (a) further comprises:

storing at least one value based on the at least one measure of the in-phase and quadrature-phase components in a memory to provide at least one stored value for subsequent comparison.

20. The method of claim 19, wherein step (a) further comprises:

detecting the in-phase and quadrature-phase components with a previously stored at least one measure and determining if the in-phase and quadrature-phase components of a newly received signal are different from the previously stored at least one measure by more than a predetermined threshold amount.