Systems and methods for far-field communication using a repurposed antenna

1. A method, comprising:

determining whether to perform near-field communication (NFC)-type operations in a near-field mode or a far-field mode;

performing the NFC-type operations inside a near-field region using an NFC loop antenna when in the near-field mode;

performing the NFC-type operations outside the near-field region using a repurposed wireless wide area network (WWAN) antenna when in the far-field mode; and

performing, in response to determining the far-field mode, a packet arbitration procedure for WWAN communication and the NFC-type operations outside the near-field region.

2. The method of claim 1 , wherein the NFC-type operations include wireless communication based on NFC protocols or radio frequency identification (RFID) protocols.

3. The method of claim 1 , wherein performing the NFC-type operations outside the near-field region comprises transmitting or receiving a carrier signal operating in a far-field region using the repurposed WWAN antenna.

4. The method of claim 1 , wherein the NFC-type operations are performed in a near-radiating region, a transition region or a radiating region.

5. The method of claim 1 , wherein the NFC-type operations are performed by a far-field radio.

6. The method of claim 1 , wherein determining whether to perform NFC-type operations in the near-field mode or the far-field mode is based on polling in the near-field region and a far-field region.

7. The method of claim 1 , wherein determining whether to perform NFC-type operations in the near-field mode or the far-field mode is based on a user selecting to operate a software application that is configured to operate in near-field mode or far-field mode.

8. The method of claim 1 , wherein determining whether to perform NFC-type operations in the near-field mode or the far-field mode is based on location information.

9. The method of claim 1 , wherein the NFC-type operations are performed by an NFC controller.

10. The method of claim 1 , further comprising adjusting a matching network from a first impedance used in the near-field mode to a second impedance used in the far-field mode, wherein the first impedance produces a first resonant peak that coincides with a near-field frequency and the second impedance produces a second resonant peak that coincides with a far-field frequency.

11. The method of claim 1 , wherein the WWAN antenna is coupled to an NFC controller and a WWAN block with a diplexer.

12. The method of claim 1 , wherein the repurposed WWAN antenna is used for wireless local area network (WLAN) communication or Bluetooth (BT) communication.

13. The method of claim 12 , wherein WLAN operations and NFC-type operations share a common radio and the repurposed WWAN antenna.

14. The method of claim 13 , wherein the common radio is a WLAN 802.11 ah radio that is reconfigurable for NFC-type operations in a far-field region.

15. The method of claim 13 , wherein base band signals from WLAN operations and NFC-type operations are multiplexed to the common radio.

16. The method of claim 12 , wherein WLAN operations and NFC-type operations share a low noise amplifier (LNA) and share a power amplifier (PA) for full concurrency.

17. The method of claim 1 , wherein a media access control (MAC), modem and radio used for wireless local area network (WLAN) communication are reconfigured for NFC-type operations.

18. The method of claim 1 , further comprising:

determining whether a far-field frequency for NFC-type operations is supported by the repurposed WWAN antenna alone; and

combining the repurposed WWAN antenna and an NFC loop antenna to create a composite antenna for performing NFC-type operations outside the near-field region when the far-field frequency is lower than can be supported by the repurposed WWAN antenna alone.

19. The method of claim 1 , further comprising performing concurrent NFC-type operations inside the near-field region using a NFC loop antenna and outside the near-field region using the repurposed WWAN antenna.

20. The method of claim 1 , wherein performing the NFC-type operations outside a near-field region comprises performing a polling frequency sweep using far-field frequencies.

21. The method of claim 1 , wherein the WWAN antenna is configured for cellular communication.

22. A wireless communication device, comprising:

a processor;

a memory in communication with the processor; and

instructions stored in the memory, the instructions executable by the processor to:

determine whether to perform near-field communication (NFC)-type operations in a near-field mode or a far-field mode;

perform the NFC-type operations inside a near-field region using an NFC loop antenna when in the near-field mode;

perform the NFC-type operations outside the near-field region using a repurposed wireless wide area network (WWAN) antenna when in the far-field mode; and

perform, in response to determining the far-field mode, a packet arbitration procedure for WWAN communication and the NFC-type operations outside the near-field region.

23. The wireless communication device of claim 22 , wherein the NFC-type operations include wireless communication based on NFC protocols or radio frequency identification (RFID) protocols.

24. The wireless communication device of claim 22 , wherein performing the NFC-type operations outside the near-field region comprises transmitting or receiving a carrier signal operating in a far-field region using the repurposed WWAN antenna.

25. The wireless communication device of claim 22 , wherein the NFC-type operations are performed by a far-field radio.

26. The wireless communication device of claim 22 , wherein the NFC-type operations are performed by an NFC controller.

27. The wireless communication device of claim 22 , wherein the repurposed WWAN antenna is used for wireless local area network (WLAN) communication or Bluetooth (BT) communication.

28. An apparatus for wireless communications, comprising:

means for determining whether to perform near-field communication (NFC)-type operations in a near-field mode or a far-field mode;

means for performing the NFC-type operations inside a near-field region using an NFC loop antenna when in the near-field mode;

means for performing the NFC-type operations outside the near-field region using a repurposed wireless wide area network (WWAN) antenna when in the far-field mode; and

means for performing, in response to determining the far-field mode, a packet arbitration procedure for WWAN communication and the NFC-type operations outside the near-field region.

29. The apparatus of claim 28 , wherein the NFC-type operations include wireless communication based on NFC protocols or radio frequency identification (RFID) protocols.

30. The apparatus of claim 28 , wherein performing the NFC-type operations outside the near-field region comprises transmitting or receiving a carrier signal operating in a far-field region using the repurposed WWAN antenna.

31. The apparatus of claim 28 , wherein the NFC-type operations are performed by a far-field radio.

32. The apparatus of claim 28 , wherein the NFC-type operations are performed by an NFC controller.

33. The apparatus of claim 28 , wherein the repurposed WWAN antenna is used for wireless local area network (WLAN) communication or Bluetooth (BT) communication.

34. A computer-program product for wireless communications, the computer-program product comprising a non-transitory computer-readable medium having instructions thereon, the instructions comprising:

code for causing a wireless communication device to determine whether to perform near-field communication (NFC)-type operations in a near-field mode or a far-field mode;

code for causing the wireless communication device to perform the NFC-type operations inside a near-field region using an NFC loop antenna when in the near-field mode;

code for causing the wireless communication device to perform the NFC-type operations outside a near-field region using a repurposed wireless wide area network (WWAN) antenna when in the far-field mode; and

code for causing the wireless communication device to perform, in response to determining the far-field mode, a packet arbitration procedure for WWAN communication and the NFC-type operations outside the near-field region.

35. The computer-program product of claim 34 , wherein the NFC-type operations include wireless communication based on NFC protocols or radio frequency identification (RFID) protocols.

36. The computer-program product of claim 34 , wherein performing the NFC-type operations outside the near-field region comprises transmitting or receiving a carrier signal operating in a far-field region using the repurposed WWAN antenna.

37. The computer-program product of claim 34 , wherein the NFC-type operations are performed by a far-field radio.

38. The computer-program product of claim 34 , wherein the NFC-type operations are performed by an NFC controller.

39. The computer-program product of claim 34 , wherein the repurposed antenna is used for wireless local area network (WLAN) communication or Bluetooth (BT) communication.