Systems and methods for determining whether a companion communication device is beyond a proximity of a primary communication device

1. A system for determining whether a companion communication device is beyond a proximity of a primary communication device, the system comprising:

an analysis module configured to determine whether a wireless transaction between the primary communication device and the companion communication device is at a conclusion;

a communications module configured to emit a sensing signal based on the determination of whether the transaction is at the conclusion, the sensing signal being insufficient to elicit a response from the companion communication device; and

a detection module configured to detect a present parameter associated with the emitted sensing signal,

wherein the analysis module is configured to determine a parameter change between the present parameter and a reference parameter, and

wherein the analysis module is configured to determine whether the companion communication device is beyond the proximity of the primary communication device based on the parameter change.

2. The system of claim 1 , wherein the transaction comprises an exchange of data between the primary communication device and the companion communication device to carry out an objective indicated by a user of the primary communication device.

3. The system of claim 1 , wherein the analysis module is configured to determine when a user of the primary communication device terminates the transaction or when the transaction times out.

4. The system of claim 1 , wherein the communications module is configured to emit the sensing signal if the transaction is determined to be at the conclusion.

5. The system of claim 1 , wherein the sensing signal comprises a plurality of pulses, and wherein a pulse width of each of the plurality of pulses is between 20 and 100 microseconds.

6. The system of claim 1 , wherein the reference parameter is predetermined.

7. The system of claim 1 , wherein the communications module is configured to measure the reference parameter when the companion communication device is within the proximity of the primary communication device.

8. The system of claim 1 , wherein the reference parameter comprises at least one of a reference load seen at an antenna of the primary communication device, a reference power of the sensing signal, a reference phase of the sensing signal, and a reference amplitude of the sensing signal.

9. The system of claim 1 , wherein the present parameter comprises at least one of a present load seen at an antenna of the primary communication device, a present power of the emitted sensing signal, a present phase of the emitted sensing signal, and a present amplitude of the emitted sensing signal.

10. The system of claim 1 , wherein the communications module is configured to emit the sensing signal in response to user input received by the primary communication device.

11. The system of claim 1 , wherein the communications module is configured to refrain from polling the companion communication device based on the conclusion of the transaction.

12. The system of claim 11 , wherein the polling comprises:

transmitting a polling signal to the companion communication device, wherein the polling signal is sufficient to elicit a response from the companion communication device; and

detecting the response from the companion communication device based on the transmitted polling signal.

13. The system of claim 11 , wherein the communications module is configured to emit the sensing signal in response to the refraining.

14. The system of claim 1 , wherein the parameter change comprises a difference in value between the present parameter and the reference parameter, the parameter change representing at least one of a decrease in load seen at an antenna of the primary communication device, an increase in power of the emitted sensing signal, a change in phase of the emitted sensing signal, and an increase in amplitude of the emitted sensing signal.

15. The system of claim 1 , wherein the analysis module is configured to determine that the companion communication device is beyond the proximity of the primary communication device if the parameter change is greater than or equal to a predetermined threshold.

16. A computer-implemented method for determining whether a companion communication device is beyond a proximity of a primary communication device, the method comprising:

determining whether a wireless transaction between the primary communication device and the companion communication device is at a conclusion;

emitting a sensing signal based on the determination of whether the transaction is at the conclusion, the sensing signal comprising a plurality of pulses, each of the plurality of pulses having a pulse width;

detecting a present parameter associated with the emitted sensing signal;

determining a parameter change between the present parameter and a reference parameter; and

determining whether the companion communication device is beyond the proximity of the primary communication device based on the parameter change.

17. The method of claim 16 , further comprising maintaining emission of the sensing signal until the companion communication device is determined to be beyond the proximity of the primary communication device, the sensing signal being insufficient to power the companion communication device.

18. The method of claim 16 , wherein determining whether the wireless transaction is at the conclusion comprises determining if an objective of the transaction has been completed or if the objective has failed.

19. A non-transitory machine-readable medium encoded with executable instructions for determining whether a companion near field communication (NFC) device is beyond a proximity of a primary NFC device, the instructions comprising code for:

determining whether a wireless transaction between the primary NFC device and the companion NFC device is at a conclusion;

emitting, via an antenna of the primary NFC device, a sensing signal if the transaction is determined to be at the conclusion;

detecting a present parameter associated with the emitted sensing signal;

determining a parameter change between the present parameter and a reference parameter when a response to the sensing signal is not received from the companion NFC device; and

determining whether the companion NFC device is beyond the proximity of the primary NFC device based on the parameter change.

20. The non-transitory machine-readable medium of claim 19 , wherein the parameter change comprises a difference in value between the present parameter and the reference parameter, the parameter change representing at least one of a change in load seen at the antenna, a change in power of the emitted sensing signal, a change in phase of the emitted sensing signal, or a change in amplitude of the emitted sensing signal.

21. The non-transitory machine-readable medium of claim 20 , wherein determining whether the companion NFC device is beyond the proximity of the primary NFC comprises code for determining that the companion NFC device is beyond the proximity of the primary NFC device if the parameter change represents a decrease in the load of the antenna, an increase in the power of the emitted sensing signal, a change in the phase of the emitted sensing signal, or an increase in the amplitude of the emitted sensing signal.