RF PROTOCOL WITH VARIABLE PERIOD WAKEUP

Abstract

A remote wake-up assembly is provided including a remote device containing logic adapted to: generate a pre-amble signal comprising a plurality of pre-determined signal pulses sequentially varied throughout a pre-amble period; and generate a main message signal after a wake-up time-period. A receiver system is included containing logic adapted to: poll for the signal pulses, the receiver system polling comprising an on-state having a on-state length sufficient for receiving at least two of the sequentially varied signal pulses; determine the wake-up time-period using said at least two of the signal pulses; place the receiver system into a low-power sleep state during the remaining portion of said wake-up time-period; reactivate the receiver system at the end of the wake-up time-period; and receive the main message.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration of remote wake-up assembly in accordance with the present invention.

FIG. 2 is an illustration of the remote signal and receiver polling utilized by the remote wake-up assembly illustrated in FIG. 1.

Claims

1. A method of remotely activating an automotive system comprising: generating a pre-amble signal using a remote device, said pre-amble signal comprising a plurality of signal pulses sequentially varied throughout a pre-amble period;generating a main message signal after a wake-up time-period using said remote device;polling for said signal pulses using a receiver system, said polling comprising an on-state of said receiver system having a on-state length sufficient for receiving at least two of said sequentially varied signal pulses;determining said wake-up time-period using said at least two of said sequentially varied signal pulses;placing said receiver system into a low-power sleep state during the remaining portion of said wake-up time-period; andreactivating said receiver system at the end of said wake-up time-period; receiving said main message using said receiver system.

2. A method as described in claim 1, wherein said signal pulses comprise: a countdown sequence comprising a continuously diminishing pulse period.

3. A method as described in claim 1, wherein said on-state length is sufficient for receiving at least three of said signal pulses.

4. A method as described in claim 1, wherein said signal pulses comprise pulse on-widths of approximately 100 microseconds and pulse-off widths less than 1000 microseconds.

5. A method as described in claim 1, wherein preamble signal comprises a preamble length greater than 40,000 microseconds.

6. A method as described in claim 1, wherein said polling comprises an off-state length vs. on-state length ration greater than three to one.

7. A method as described in claim 1, wherein said polling comprises an off-state length of approximately 40 milliseconds and an on-state length of approximately 5 milliseconds.

8. A method as described in claim 1, wherein said receiver system draws less than 1 milliamp quiescent current during said wake-up time period.

9. A remote wake-up assembly comprising: a remote device containing logic adapted to: generate a pre-amble signal, said pre-amble signal comprising a plurality of pre-determined signal pulses sequentially varied throughout a pre-amble period; andgenerate a main message signal after a wake-up time-period; anda receiver system containing logic adapted to: poll for said signal pulses, said receiver system polling comprising an on-state having a on-state length sufficient for receiving at least two of said sequentially varied signal pulses;determine said wake-up time-period using said at least two of said sequentially varied signal pulses;place said receiver system into a low-power sleep state during the remaining portion of said wake-up time-period;

10. A remote wake-up assembly as described in claim 9, wherein said signal pulses comprise: a countdown sequence comprising a continuously diminishing pulse period.

11. A remote wake-up assembly as described in claim 9, wherein said on-state length is sufficient for receiving at least three of said signal pulses.

12. A remote wake-up assembly as described in claim 9, wherein said signal pulses comprise pulse on-widths of approximately 100 microseconds and pulse-off widths less than 1000 microseconds.

13. A remote wake-up assembly as described in claim 9, wherein said preamble signal comprises a preamble length greater than 40,000 microseconds.

14. A remote wake-up assembly as described in claim 9, wherein said poll for said signal pulses comprises an off-state length vs. on-state length ration greater than three to one.

15. A remote wake-up assembly as described in claim 9, wherein said poll for said signal pulses comprises an off-state length of approximately 40 milliseconds and an on-state length of approximately 5 milliseconds.

16. A remote wake-up assembly as described in claim 9, wherein said receiver system draws less than 1 milliamp quiescent current during said wake-up time-period.

17. A remote wake-up assembly comprising: a remote device containing logic adapted to: generate a pre-amble signal, said pre-amble signal comprising a countdown sequence comprised of a plurality of pre-determined signal pulses throughout a pre-amble period; andgenerate a main message signal after a wake-up time-period; anda receiver system containing logic adapted to: poll for said signal pulses, said receiver system polling comprising an on-state having a on-state length sufficient for receiving at least two of said signal pulses;determine said wake-up time-period using said at least two of said signal pulses;place said receiver system into a low-power sleep state during the remaining portion of said wake-up time-period;reactivate said receiver system at the end of said wake-up time-period; andreceive said main message.

18. A remote wake-up assembly as described in claim 17, wherein said receiver system polling comprises an on-state length to off-state length of less than 50%.

19. A remote wake-up assembly as described in claim 17, wherein said signal pulses comprise pulse on-widths less than one quarter of pulse-off widths.

20. A remote wake-up assembly as described in claim 17, wherein said pre-amble period is increased such that a receiver data frame length may be maximized.