Synchronizing wakeup operations in electronic devices

1. An electronic device, comprising:

a first receiver configured to receive a first wireless signal;

a first timing module configured to wake up the first receiver from a first sleep state and to generate a synchronization signal indicating a wakeup time of the first receiver;

a second receiver configured to receive a second wireless signal; and

a second timing module configured to:

receive the synchronization signal;

wake up the second receiver from a second sleep state based on the synchronization signal; and

predict a future wakeup time of the first receiver based on the synchronization signal and a time interval between wakeups of the first receiver.

2. The electronic device of claim 1 , wherein the first wireless signal comprises a cellular signal from a base station.

3. The electronic device of claim 2 , wherein the second wireless signal comprises a Bluetooth signal from a wireless device.

4. The electronic device of claim 1 , further comprising a processor configured to process a signal from the second receiver, wherein the second timing module is further configured to wake up the processor from a third sleep state based on the synchronization signal.

5. The electronic device of claim 4 , wherein the second wireless signal comprises a Bluetooth signal.

6. The electronic device of claim 1 , further comprising a processor configured to process a signal from the second receiver, wherein the second timing module is further configured to wake up the second receiver and the processor based on the synchronization signal to perform a page scan operation.

7. The electronic device of claim 1 , further comprising a processor configured to process a signal from the second receiver, wherein the second timing module is further configured to wake up the second receiver and the processor based on the synchronization signal to perform an inquiry scan operation.

8. The electronic device of claim 1 , further comprising a processor configured to process a signal from the second receiver, wherein the second timing module is further configured to wake up the second receiver and the processor based on the synchronization signal to perform a sniff mode operation.

9. The electronic device of claim 1 , wherein the second timing module is further configured to negotiate a sniff start time with a wireless device based on the synchronization signal.

10. The electronic device of claim 1 , wherein the second timing module is further configured to negotiate a sniff time interval with a wireless device based on the synchronization signal.

11. The electronic device of claim 1 , wherein the second timing module is further configured to negotiate a sniff start time with a wireless device based on the predicted wakeup time.

12. A method of synchronizing wakeup operations of an electronic device, comprising:

waking up a first receiver from a first sleep state to receive a first wireless signal;

generating a synchronization signal indicating a wakeup time of the first receiver;

waking up a second receiver from a second sleep state based on the synchronization signal to receive a second wireless signal; and

predicting a future wakeup time of the first receiver based on the synchronization signal and a time interval between wakeups of the first receiver.

13. The method of claim 12 , wherein the first wireless signal comprises a cellular signal.

14. The method of claim 13 , wherein the second wireless signal comprises a Bluetooth signal.

15. The method of claim 12 , further comprising waking up a processor from a third sleep state based on the synchronization signal to process a signal from the second receiver.

16. The method of claim 15 , wherein the second wireless signal comprises a Bluetooth signal.

17. The method of claim 12 , further comprising waking up the second receiver and a processor based on the synchronization signal to perform a page scan operation.

18. The method of claim 12 , further comprising waking up the second receiver and a processor based on the synchronization signal to perform an inquiry scan operation.

19. The method of claim 12 , further comprising waking up the second receiver and a processor based on the synchronization signal to perform a sniff mode operation.

20. The method of claim 12 , further comprising negotiating a sniff start time with a wireless device based on the synchronization signal.

21. The method of claim 12 , further comprising negotiating a sniff time interval with a wireless device based on the synchronization signal.

22. The method of claim 12 , further comprising:

negotiating a sniff start time with a wireless device based on the predicted wakeup time.

23. A system for synchronizing wakeup operations, comprising:

means for waking up a first receiver of an electronic device from a first sleep state to receive a first wireless signal;

means for generating a synchronization signal indicating a wakeup time of the first receiver;

means for waking up a second receiver of the electronic device from a second sleep state based on the synchronization signal to receive a second wireless signal; and

means for predicting a future wakeup time of the first receiver based on the synchronization signal and a time interval between wakeups of the first receiver.

24. The system of claim 23 , wherein the first signal comprises a cellular signal.

25. The system of claim 24 , wherein the second wireless signal comprises a Bluetooth signal.

26. The system of claim 23 , further comprising:

means for waking up a processor from a third sleep state based on the synchronization signal to process a signal from the second receiver.

27. The system of claim 26 , wherein the second wireless signal comprises a Bluetooth signal.

28. The system of claim 23 , further comprising:

means for waking up the second receiver and a processor based on the synchronization signal to perform a page scan operation.

29. The system of claim 23 , further comprising:

means for waking up the second receiver and a processor based on the synchronization signal to perform an inquiry scan operation.

30. The system of claim 23 , further comprising:

means for waking up the second receiver and a processor based on the synchronization signal to perform a sniff mode operation.

31. The method of claim 23 , further comprising:

means for negotiating a sniff start time with a wireless device based on the synchronization signal.

32. The method of claim 23 , further comprising:

means for negotiating a sniff time interval with a wireless device based on the synchronization signal.

33. The method of claim 23 , further comprising:

means for negotiating a sniff start time with a wireless device based on the predicted wakeup time.

34. A processing system, comprising:

an input port;

an output port; and

a processor configured to

receive a synchronization signal indicating a wakeup time of a first receiver of an electronic device;

wake up a second receiver of the electronic device from a sleep state based on the synchronization signal to receive a wireless signal; and

wake up a second processor from a second sleep state based on the synchronization signal, wherein the second processor is configured to process a signal from the second receiver.

35. The processing system of claim 34 , wherein the second processor is further configured to wakeup the first receiver and to generate the synchronization signal.

36. The processing system of claim 34 , wherein the first receiver is configured to receive a cellular signal.

37. The processing system of claim 36 , wherein the second receiver is configured to receive a Bluetooth signal.

38. The processing system of claim 34 , wherein the wireless signal comprises a Bluetooth signal.

39. The processing system of claim 34 , wherein the processor is configured to wake up the second receiver and the second processor based on the synchronization signal to perform a page scan operation.

40. The processing system of claim 34 , wherein the processor is further configured to wake up the second receiver and the second processor based on the synchronization signal to perform an inquiry scan operation.

41. The processing system of claim 34 , wherein the processor is further configured to wake up the second receiver and the second processor based on the synchronization signal to perform a sniff mode operation.

42. The processing system of claim 34 , wherein the processor is further configured negotiate a sniff start time with a wireless device based on the synchronization signal.

43. The processing system of claim 34 , wherein the processor is further configured negotiate a sniff time interval with a wireless device based on the synchronization signal.

44. The processing system of claim 34 , wherein the processor is further configured to:

predict a future wakeup time of the first receiver based on the synchronization signal and a time interval between wakeups of the first receiver; and

negotiate a sniff start time with a wireless device based on the predicted wakeup time.

45. A non-transitory computer readable medium comprising instructions executable by a processing system in an electronic device, the instructions comprising code for:

receiving a synchronization signal indicating a wakeup time of a first receiver;

waking up a second receiver from a sleep state based on the synchronization signal to receive a wireless signal; and

predicting a future wakeup time of the first receiver based on the synchronization signal and a time interval between wakeups of the first receiver.

46. The machine-readable medium of claim 45 , further comprising instructions for:

waking up the first receiver; and

generating the synchronization signal.

47. The machine-readable medium of claim 45 , wherein the first receiver is configured to receive a cellular signal.

48. The machine-readable medium of claim 45 , wherein the wireless signal comprises a Bluetooth signal.

49. The machine-readable medium of claim 45 , further comprising instructions for:

waking up a processor from a second sleep state based on the synchronization signal to process a signal from the second receiver.

50. The machine-readable medium of claim 49 , wherein the wireless signal comprises a Bluetooth signal.

51. The machine-readable medium of claim 45 , further comprising instructions for:

waking up the second receiver and a processor based on the synchronization signal to perform a page scan operation.

52. The machine-readable medium of claim 45 , further comprising instructions for:

waking up the second receiver and a processor based on the synchronization signal to perform an inquiry scan operation.

53. The machine-readable medium of claim 45 , further comprising instructions for:

waking up the second receiver and a processor based on the synchronization signal to perform a sniff mode operation.

54. The machine-readable medium of claim 45 , further comprising instructions for:

negotiating a sniff start time with a wireless device based on the synchronization signal.

55. The machine-readable medium of claim 45 , further comprising instructions for:

negotiating a sniff time interval with a wireless device based on the synchronization signal.

56. The machine-readable medium of claim 45 , further comprising instructions for:

negotiating a sniff start time with a wireless device based on the predicted wakeup time.