Fast-sleep configuration for CDMA slotted mode

• US 6,937,578 B1
• Filed: 02/02/2000
• Issued: 08/30/2005
• Est. Priority Date: 02/02/2000
• Status: Expired due to Term

• Current Assignee: Beijing Xiaomi Mobile Software Co., Ltd. (Xiaomi Corp.)
• Original Assignee: DENSO Corporation
• Inventors: Hunzinger, Jason F.
• Primary Examiner(s): Patel, Ajit
• Application Number:
  US09/497,076
• Time in Patent Office: 2,036 Days
• Field of Search: 370/311, 370/335, 370/318, 370/328, 370/342, 370/332, 370/441, 455/574, 455/13.4, 455/522, 455/422, 340/7.32, 340/7.34, 340/7.36, 340/7.38
• US Class Current: 370/311
• CPC Class Codes: H04B 1/7075 with code phase acquisition

Abstract

A sleep timing system for a wireless mobile station includes a circuitry that enables the mobile station to enter a low-power mode immediately upon command. The circuitry transitions the mobile station into the low-power mode without waiting for a next pseudo-random noise (PN) sequence roll boundary. The timing system includes a counter, a wakeup time register, and a sleep timer. The counter receives a PN sequence and estimates a number of clock cycles to the next PN sequence roll boundary. The wakeup time register may be set with a sleep time value in terms of number of PN roll boundaries. The register is provided with a new sleep time value that includes the number of clock cycles to the next PN sequence roll boundary.

Claims

1. A timing system for a wireless mobile station, the system comprising:

a communication element operating to communicate with a remote station; and

a circuit that enables the mobile station to enter a low-power mode after a next timing boundary when a command is received;

wherein the circuit artificially slews local system time upon receipt of said command so that the next timing boundary occurs substantially immediately.

2. The system of claim 1, wherein said timing boundary is a pseudo-random noise sequence roll boundary, and said circuit includes a counter to receive a pseudo-random noise sequence, said counter estimating a number of clock cycles to a next pseudo-random noise sequence roll boundary.

3. The system of claim 2, wherein said circuit further includes a wakeup time register to receive a sleep time value in terms of a number of pseudo-random noise roll boundaries, said wakeup time register providing a new sleep time value that includes said number of clock cycles to said next pseudo-random noise sequence roll boundary.

4. The system of claim 3, wherein said wakeup time register includes a summing element that sums said received sleep time value with said number of clock cycles to said next pseudo random noise sequence roll boundary.

5. The system of claim 3, wherein said circuit further includes a sleep timer configured to issue a sleep command at the beginning of said low-power mode, and to keep internal time during said low-power mode, said sleep timer providing a wakeup signal when said internal time reaches said new sleep time value.

6. The system of claim 5, wherein said sleep timer includes a signal generator operating to generate said wakeup signal based on said internal time and said new sleep time value.

7. A method for managing sleep timing operations in a CDMA slotted-paging mode, comprising:

monitoring allotted slots or interrupts;

waking up at an appropriate time to service said slots or interrupts;

immediately entering a low-power mode when commanded;

slewing local system time before entering said low-power mode;

determining a difference between said slewed local system time and correct system time that corresponds to said allotted slots; and

incorporating said difference into the duration of said low-power mode.

8. The method of claim 7, wherein said timing operations include:

storing a calculated wakeup time including time to next pseudo-random noise sequence roll boundary, upon command to enter a low-power mode; and

transitioning into said low-power mode without waiting for said roll boundary.

9. The method of claim 8, further comprising:

receiving a wakeup time based only on a number of pseudo-random nose sequence roll boundaries;

estimating said time to next pseudo-random noise sequence roll boundary; and

providing said calculated wakeup time based on said time to next pseudo-random noise sequence roll boundary and said wakeup time based only on said number of pseudo-random noise roll boundaries.

10. The method of claim 8, further comprising:

providing an internal sleep time; and

transitioning out of said low-power mode when said sleep time reaches said calculated wakeup time.

11. A method for managing sleep timing operations in a wireless mobile device, comprising:

slewing a local time reference so that an artificial timing roll boundary occurs immediately upon a command to enter a low-power mode, wherein said artificial timing roll boundary occurs sooner than a next timing roll boundary;

storing a calculated wakeup time based in part on a time period to said next timing roll boundary, upon the command to enter said low-power mode; and

transitioning into said low-power mode in accordance with said local time reference without waiting for said next timing roll boundary.

12. A computer program on a computer-readable storage medium having executable instructions that enable a mobile station to enter a low-power mode substantially immediately upon command, said program enabling the computer to:

slew a local time reference so that an artificial timing roll boundary occurs immediately upon a command to enter a low-power mode, wherein said artificial timing roll boundary occurs sooner than a next timing roll boundary;

store a calculated wakeup time based in part on a time period to said next timing roll boundary, upon the command to enter said low-power mode; and

transition into said low-power mode in accordance with said local time reference without waiting for said next timing roll boundary.

13. A wireless telephone device, comprising:

a housing; and

a sleep timing system within the housing, said system enabling the device to enter a low-power mode after a next roll boundary when a command is received;

wherein the sleep timing system artificially slews local system time upon receipt of said command so that the next roll boundary occurs substantially immediately.

14. The device of claim 13, wherein said roll boundary is a pseudo-random noise sequence roll boundary.

15. The device of claim 14, wherein said sleep timing system includes:

a counter to receive a pseudo-random noise sequence, said counter estimating a number of clock cycles to said next pseudo-random noise sequence roll boundary;

a wakeup time register to receive a sleep time value in terms of number of pseudo-random noise roll boundaries, said wakeup time register providing a new sleep time value that includes said number of clock cycles to said next pseudo-random noise sequence roll boundary; and

a sleep timer configured to issue a sleep command at the beginning of said low-power mode, and to keep internal time during said low-power mode, said sleep timer providing a wakeup signal when said internal time reaches said new sleep time value.

16. A method for managing sleep timing operations in a wireless mobile device, comprising:

computing a time difference between a first system time that corresponds to a desired start time of sleep and a second system time that corresponds to a system time event;

slewing a local reference clock from a first time that is synchronized with system timing to a second time that is offset from the system timing by the time difference; and

entering sleep when the local reference clock reaches a local time event.

17. The method of claim 16, further comprising:

returning the local reference clock to the first time synchronized with the system timing after sleep.

18. The method of claims 16, wherein stewing the local reference clock comprises setting the local reference clock behind to indicate thereafter a time that is earlier than actual system time.

19. The method of claim 16, wherein stewing the local reference clock comprises setting the local reference clock ahead to indicate thereafter a time that is later than actual system time.

20. The method of claim 16, wherein the local reference clock includes a timing counter that maintains a time count.

21. The method of claim 20, wherein the system time event is a rollover of the time count that would occur in the future if the local system clock remained synchronized to system time, and

the local time event is a rollover of the time count of the slewed local reference clock that occurs earlier than the system time event.

22. The method of claim 16, further comprising:

determining a third time corresponding to a desired future time to wakeup from sleep;

computing a sleep duration based on the third time; and

exiting sleep when the sleep duration has expired.

23. The method of claim 16, wherein the sleep duration includes the time difference.

24. A timing system for a wireless mobile station that uses periodic timing boundaries to control a low-power mode, the timing system comprising:

a counter that determines a time interval to a next timing boundary upon receiving a command;

a calculating element that calculates a sleep time period based on the time interval; and

a signal generator that produces a sleep command signal after the calculating element calculates the sleep time period so that the wireless mobile station enters the low-power mode without waiting the next timing boundary, and produces a wakeup signal when the sleep time period has elapsed.

25. The timing system according to claim 24, wherein the calculating element has a summing element that adds the time interval to a normal sleep time to calculate the sleep time period, wherein the normal sleep time is defined by the timing boundaries.

26. The timing system according to claim 24, wherein the command is issued when user input is ended.