Method and apparatus for reducing power consumption of slotted mode mobile communication terminal

• US 20030148800A1
• Filed: 01/17/2003
• Published: 08/07/2003
• Est. Priority Date: 01/17/2002
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Ju-Bong
• Granted Patent: US 7,142,896 B2
• Time in Patent Office: Days
• US Class Current: 455/574
• CPC Class Codes: H04B 1/1615 Switching on; Switching off, e.g. remotely battery saving circuits associated with selective call operation H04W52/00; details of power consumption reduction in a PLL, H03L7/0802, H03L7/14, H03L2207/08, H03L2207/18; muting amplifiers by gain control see H03G3/34
• CPC Class Codes: H04W 52/0235 where the received signal is a power saving command
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A method and apparatus for reducing power consumption of a mobile communication terminal operated at a slotted mode in a spread spectrum communication system such as a CDMA cellular mobile communication system. The mobile communication terminal reduces a paging channel monitoring time by entering a sleep mode or a wake-up mode at an arbitrary timing instead of a PN code rollover period, resulting in the increment of a standby time of the terminal.

Claims

1. A method for increasing a sleep period of a communication circuitry in a mobile communication terminal, the communication circuitry being repeatedly and periodically woken up for monitoring a paging channel received from a mobile communication system in an allocated paging channel slot period that is periodically repeated, the communication circuitry sleeping in a non-allocated paging channel slot period, the method comprising the steps of:

a) setting up hardware parameters for powering off the communication circuitry when a sleep mode determination command is generated in the allocated paging channel slot period; and

b) when the hardware parameters setup is completed, immediately entering a sleep mode to power off the communication circuitry.

2. The method as set forth in claim 1, further comprising the steps of:

c) determining a time period for enabling the mobile communication terminal to establish synchronization re-acquisition with the mobile communication system after entering the sleep mode, and then being woken up at a time prior to an initiation timing of the next allocated paging channel slot period by the determined time period.

3. The method as set forth in claim 2, wherein the step c) comprises the sub-steps of:

calculating a first time period from the sleep mode determination command to an initiation timing of the next allocated paging channel slot period in units of a PN (Pseudo-random Noise) code rollover period, and determining the first time period as a reference sleep time period;

measuring a second time period to a powering-off timing of the communication circuitry since a sleep mode indication command to the communication circuitry is generated in response to the sleep mode determination command, and storing the second time period as a sleep time offset;

determining a wake-up time offset considering a time period needed for the mobile communication terminal to establish a synchronization re-acquisition with the mobile communication system;

after entering the sleep mode, summing up the reference sleep time period, the sleep time offset and the wake-up time offset, and driving a sleep mode timer having a duty cycle of a value where a predetermined maximum time delay value is subtracted from the summed result; and

when the sleep mode timer is expired, powering on the communication circuitry by entering a wake-up mode.

4. The method as set forth in claim 3, wherein the wake-up time offset is determined depending on a coding method of the paging channel, a frame length, and a search speed of the mobile communication terminal.

5. The method as set forth in claim 3, further comprising the sub-step of:

after powering on the communication circuitry, calculating and setting a PN state corresponding to the wake-up time offset.

6. An apparatus for reducing power consumption in a mobile communication terminal, comprising:

a communication circuitry that is repeatedly and periodically woken up for monitoring a paging channel received from a mobile communication system in an allocated paging channel slot period that is periodically repeated, and sleeps in a non-allocated paging channel slot period; and

a control unit that sets up hardware parameters for powering off the communication circuitry when a sleep mode determination command is generated in the allocated paging channel slot period, and enters a sleep mode to power off the communication circuitry immediately upon completing the hardware parameters set-up.

7. The apparatus as set forth in claim 6, wherein the control unit, after entering the sleep mode, determines a time period for enabling the mobile communication terminal to establish synchronization re-acquisition with the mobile communication system, and is then woken up at a time prior to an initiation timing of the next allocated paging channel slot period by the determined time period.