Optimizing power consumption in a near field communications (NFC) environment

• US 9,054,749 B2
• Filed: 06/29/2011
• Issued: 06/09/2015
• Est. Priority Date: 06/29/2011
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Wilson, Robin Wyndham John, Royston, Philip Stewart
• Primary Examiner(s): Hanidu, Ganiyu A
• Application Number:
  US13/172,392
• Publication Number:
  US 20130005248A1
• Time in Patent Office: 1,441 Days
• Field of Search: 455 411- 412, 455/41.3, 455/574, 455/556.1, 455/62, 455/39, 455/555, 375/295, 375/259, 375/312, 375/344, 370/338, 370/331, 370/252, 370/310.1, 370/346, 370/347, 370/312, 370/329, 370/311, 370/475
• US Class Current: 1/1
• CPC Class Codes: G06K 7/10217 parameter settings controlling the transmission power of the interrogator
• 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: H04B 5/77 for interrogation
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

An apparatus and method is disclosed to optimize power consumption in a NFC environment. A first NFC capable device provides a polling command to a second NFC capable device. The second NFC capable device provides a response to the polling command. The first NFC capable device provides a read command to the second NFC capable device. The second NFC capable device provides a response to the read command that indicates an overvoltage condition is present. The first NFC capable device adjusts a power level that is to be used to transmit further commands when the overvoltage condition is present.

Claims

1. A method for optimizing power consumption in a near field communication (NFC) environment, comprising:

providing, by a first NFC device, a first communications signal including a read command at a first power to a second NFC device to recover a unique identifier (UID) of the second NFC device;

receiving, by the first NFC device, a second communications signal including a response to the read command from the second NFC device;

determining, by the first NFC device, whether a complete UID of the second NFC device has been received;

determining, by the first NFC device in response to the complete UID of the second NFC device not being received, whether the response indicates an overvoltage condition is present in the second NFC device; and

repeating the providing, the receiving, the determining whether the complete UID has been received, and the determining whether the response indicates the overvoltage condition until the complete UID of the second NFC device has been received,

wherein for each repetition, the response includes one or more other bits of the UID for each repetition.

2. The method of claim 1, further comprising:

adjusting, by the first NFC device, the first power to a second power in response to determining the over voltage condition is present.

3. The method of claim 2, further comprising:

providing, by the first NFC device, the first communications signal at the second power to recover the UID of the second NFC device;

activating, by the first NFC device, a timing mechanism; and

providing, by the first NFC device, the first communications signal at the first power to recover the UID of the second NFC device upon expiration of the timing mechanism.

4. The method of claim 1, wherein the response includes a plurality of bits, at least a first bit from among the plurality of bits indicating whether the complete UID of the second NFC device has been provided and at least a second bit from among the plurality of bits indicating whether the overvoltage condition is present in the second NFC device.

5. The method of claim 1, further comprising:

providing, by the first NFC device, a third communications signal including a polling command to the second NFC device; and

receiving, by the first NFC device, a fourth communications signal including a response to the polling command from the second NFC device.

6. The method of claim 1, further comprising:

storing, by the first NFC device, an overvoltage indicator in a memory module to indicate the presence of the overvoltage condition.

7. The method of claim 6, wherein the storing further comprises:

storing the overvoltage indicator in one or more bits of the memory module that are unused or reserved for future use by a communication standard.

8. A method for optimizing power consumption in a near field communication (NFC) environment, comprising:

receiving, by a first NFC device, a first communications signal including a read command at a first power from a second NFC device to recover a unique identifier (UID) of the first NFC device;

monitoring, by the first NFC device, the first power to determine whether an overvoltage condition is present;

providing, by the first NFC device, a second communications signal including a response to the read command to the second NFC device, the response including one or more bits of the UID and an indication of whether the overvoltage condition is present; and

repeating the monitoring and the providing until a complete UID has been provided to the second NFC device,

wherein for each repetition, the response includes one or more other bits of the UID.

9. The method of claim 8, wherein the monitoring further comprises:

comparing, by the first NFC device, the first power with an overvoltage threshold, the overvoltage condition being present when the first power is greater than the overvoltage threshold.

10. The method of claim 8, wherein the providing further comprises:

encoding, by the first NFC device, a first group of one or more bits of the response to indicate that the overvoltage condition is present.

11. The method of claim 10, wherein the providing further comprises:

encoding, by the first NFC device, a second group of the one or more bits of the response to indicate the complete UID has been provided to the second NFC device.

12. The method of claim 8, wherein the monitoring comprises:

converting, by the first NFC device, the first communications signal from alternating current (AC) to direct current (DC) to provide a rectified power; and

comparing the rectified power with the an overvoltage threshold, the overvoltage condition being present when the rectified power is greater than the overvoltage threshold.

13. The method of claim 12, wherein the monitoring further comprises:

comparing the rectified power with a reference power; and

regulating the first communications signal when the rectified power is greater than the reference power.

14. The method of claim 8, further comprising:

receiving, by the first NFC device, a third communications signal including a polling command from the second NFC device; and

providing, by the first NFC device, a fourth communications signal including a response to the polling command to the second NFC device.

20. The method of claim 11, wherein the repeating comprises:

repeating the encoding the first group of the one or more bits of the response and the encoding the second group of the one or more bits of the response until the complete UID has been provided to the second NFC device.

15. An apparatus for optimizing power consumption in a near field communication (NFC) environment, comprising:

a demodulator module configured to demodulate a first communications signal including a read command requesting one or more bits of a unique identifier (UID) of the apparatus, and

a controller module configured to;

monitor a power level of the first communications signal to determine whether an overvoltage condition is present,

provide a response to the read command in a second communications signal, the response including one or more bits of the UID and an indication of whether the overvoltage condition is present, and

continue to monitor the power level and to provide one or more subsequent responses until a complete UID has been provided, each of the one or more subsequent responses including one or more other bits of the UID and the indication of whether the overvoltage condition is present.

16. The apparatus of claim 15, wherein the response and the one or more subsequent responses comprise:

a first group of one or more bits to indicate that the overvoltage condition is present; and

a second group of one or more bits of the response to indicate whether the complete UID has been provided.

17. The apparatus of claim 16, further comprising:

a rectifier module configured to convert the first communications signal from alternating current (AC) to direct current (DC) to provide a rectified power; and

a regulator controller configured to compare the rectified power with an overvoltage threshold to determine whether the overvoltage condition is present, the overvoltage condition being present when the rectified power is greater than the overvoltage threshold.

18. The apparatus of claim 17, wherein the regulator controller is further configured to compare the rectified power with a power threshold to provide a regulation control signal, and further comprising:

a regulator module configured to adjust a power level of the first communications signal in response to the regulation control signal.

19. The apparatus of claim 15, further comprising:

an antenna module configured to;

inductively receive the first communications signal via a magnetic field,

inductively receive a third communications signal including a polling command via the magnetic field, and

provide a fourth communications signal including a response to the polling command via the magnetic field.