Partial sleep system for power savings in CDMA wireless telephone devices

• US 6,356,538 B1
• Filed: 03/30/1998
• Issued: 03/12/2002
• Est. Priority Date: 03/30/1998
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: OKI Telecom, Inc. (OKI Electric Industry Company Limited)
• Inventors: Li, Kaiping
• Primary Examiner(s): Nguyen, Chau
• Assistant Examiner(s): TRINH, DUNG N
• Application Number:
  US09/050,777
• Time in Patent Office: 1,443 Days
• Field of Search: 370/311, 370/335, 370/342, 455/343, 455/574, 455/434, 455/515, 455/38.3, 455/701, 455/702, 455/703
• US Class Current: 370/311
• CPC Class Codes: H04W 52/0225 using monitoring of external events, e.g. the presence of a signal
• CPC Class Codes: H04W 52/0283 with sequential power up or power down of successive circuit blocks, e.g. switching on the local oscillator before RF or mixer stages
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A system for operating a wireless communications device in a manner that significantly reduces the power consumption of the device. In accordance with one aspect of the invention, a system is provided for operating a wireless communications device in a low power mode including the step of controlling the operation of circuit components to operate in either a low-power standby mode or an operating mode. The system includes detecting a first condition and, in response to the detection of the first condition, operating a first set of circuit components in a low-power standby mode while operating a second set of circuit components in the operating mode. The system further includes detecting a second condition and, in response to the detection of the second condition, operating substantially all the circuit components in the operating mode. In the preferred embodiment, the system further includes detecting a third condition and, in response to the detection of the third condition, operating a third set of circuit components in a low-power standby mode while operating a fourth set of circuit components in the operating mode.

Claims

1. A method for operating a wireless communications device in a low power mode wherein the wireless device contains circuit components and communicates in accordance with a Code Division Multiple Access (CDMA) standard, the method comprising the steps of:

controlling the operation of the circuit components to operate in either a low-power standby mode or an operating mode;

detecting a first condition wherein the first condition is a slotted mode of operation;

in response to the detection of the first condition, operating a first set of circuit components in a low-power standby mode and operating a second set of circuit components in the operating mode;

detecting a second condition wherein the second condition is a scanning mode of operation; and

in response to the detection of the second condition, operating a third set of circuit components in a low-power standby mode and operating a fourth set of circuit components in the operating mode, wherein the third set of circuit components differs from the first set of circuit components.

2. The method as defined in claim 1, wherein the first set of circuit components includes at least one from the group consisting of:

a pilot channel searching component, at least one data demodulating component, an automatic gain controller unit, an arithmetic unit, and a combiner unit.

3. The method as defined in claim 1, wherein the second set of circuit components includes at least one from the group consisting of:

memory, a plurality of registers, and a state machine that controls the operation of the second set of circuit components.

4. The method as defined in claim 1, wherein the circuit components are portions of an integrated circuit device, wherein the portions comprise, in part hardware and in part executable code.

5. The method as defined in claim 1, wherein the third set of circuit components includes at least one from the group consisting of:

at least one data demodulating component, an automatic gain controller unit, an arithmetic unit, and a combiner unit.

6. The method as defined in claim 1, wherein the fourth set of circuit components includes at least one from the group consisting of:

memory, a pilot channel searching component, an arithmetic unit, a plurality of registers, and a state machine that controls the operation of the fourth set of circuit components.

7. A method for operating a wireless telecommunications device communicating in accordance with a CDMA standard after device power-up and initialization, and as the device enters a slotted mode operation, the method comprising the steps of:

(a) placing the device into a sleep mode, wherein during the sleep mode a first set of circuit components is operated in a low-power mode;

(b) waiting a predetermined period of time;

(c) waking the device from the sleep mode;

(d) performing a scan of a base station pilot channel sequences to maintain synchrony with the CDMA system time, wherein while the scan is performed a second set of circuit components is operated in a low-power mode, the second set of circuit components differing from the first set of circuit components;

(e) monitoring a paging channel slot; and

(f) repeating steps (a) through (e).

8. The method as defined in claim 7, wherein the first set of circuit components include a plurality of components selected from the group consisting of:

a radio-frequency transmitter/receiver, an analog front end, a CDMA modem circuit, a central processing unit, a digital signal processor, a coder/decoder, and an interface controller.

9. The method as defined in claim 8, wherein the low-power mode is further defined by operating a plurality of components within the CDMA modem circuit in a standby mode, the plurality of components within the CDMA modem circuit includes at least one from the group consisting of:

a pilot channel searching component, at least one data demodulating component, an automatic gain controller unit, an arithmetic unit, and a combiner unit.

10. The method as defined in claim 7, wherein the predetermined period of time is defined so that the device wakes prior to an expected arrival of a paging channel slot, to ensure that the pilot channel scan is performed prior to the paging channel slot.

11. A method for operating a wireless telecommunications device communicating in accordance with a CDMA standard as the device enters a scanning mode whereby the device scans for alternate base stations in a different CDMA frequency mode of operation comprising the steps of:

saving the current state of the device;

placing the device into a sleep mode, wherein the sleep mode is defined by operating a first set of circuit components in a low-power mode;

performing a scanning operation, wherein during the scanning operation a second set of circuit components is operated in a low-power mode, the second set of circuit components differs from the first set of circuit components;

waking the device from the sleep mode; and

restoring the saved state of the device.

12. The method as defined in claim 11, wherein the first set of circuit components include a plurality of components selected from the group consisting of:

a radio-frequency transmitter/receiver, an analog front end, a CDMA modem circuit, a central processing unit, a digital signal processor, a coder/decoder, and an interface controller.

13. The method as defined in claim 12, wherein the low-power mode is further defined by operating a plurality of components within the CDMA modem circuit in a standby mode, the plurality of components within the CDMA modem circuit includes at least one from the group consisting of:

at least one data demodulating component, an automatic gain controller unit, and a combiner unit.

14. A low-power wireless telecommunications device for communicating in accordance with a CDMA standard comprising:

a plurality of circuit components, including a CDMA modem circuit;

a first mechanism configured to operate the plurality of circuit components in either a first low-power sleep mode wherein the first low-power sleep mode comprises operating a first set of circuit components in slotted mode, or a second low-power sleep mode wherein the second low-power sleep mode comprises operating a second set of circuit components in a scanning mode where the second set of circuit components differs from the first set of circuit components, the first mechanism operating the plurality of circuit components in one of the low-power sleep modes when the device is not in use in a phone call;

a second mechanism operative when the device is operating in one of the low-power sleep modes, the second mechanism periodically checking whether there is a demand for the device; and

a third mechanism responsive to the second mechanism for waking the device from the sleep mode.

15. The device as defined in claim 14, wherein the first sleep mode is defined by operating a set of circuit components within the CDMA modem circuit in a low-power mode, the set of circuit components including at least one from the group consisting of:

a pilot channel searching component, at least one data demodulating component, an automatic gain controller unit, an arithmetic unit, and a combiner unit.

16. The device as defined in claim 14, wherein the second sleep mode is defined by operating a set of circuit components within the CDMA modem circuit in a low-power mode, the set of circuit components including at least one from the group consisting of:

at least one data demodulating component, an automatic gain controller unit, and a combiner unit.

17. The device as defined in claim 14, wherein the first mechanism includes a processing component and executable program code for operating the processing component as a state machine.

18. A low-power wireless telecommunications device for communicating in accordance with a CDMA standard comprising:

a plurality of circuit components, including a CDMA modem circuit;

first means for operating the plurality of circuit components in either a first low-power sleep mode wherein the first low-power sleep mode comprises operating a first set of circuit components in slotted mode, or a second low-power sleep mode wherein the second low-power sleep mode comprises operating a second set of circuit components in scanning mode where the second set of circuit components differs from the first set of circuit components, the first means operating the plurality of circuit components in one of the low-power sleep modes when the device is not in use;

second means for periodically checking whether there is a demand for the device; and

third means responsive to the second means for waking the device from the low-power sleep mode.