POWER SAVING METHOD ADAPTABLE IN GNSS DEVICE

• US 20100103038A1
• Filed: 10/27/2008
• Published: 04/29/2010
• Est. Priority Date: 10/27/2008
• Status: Active Grant

• Current Assignee: MediaTek, Inc.
• Original Assignee: MediaTek, Inc.
• Inventors: Lo, Chi Ya, Yeh, Hsin-Chung
• Granted Patent: US 8,836,576 B2
• Time in Patent Office: Days
• US Class Current: 342/357.740
• CPC Class Codes: G01S 19/30 code related G01S19/246 takes precedence
• CPC Class Codes: G01S 19/34 Power consumption
• CPC Class Codes: G01S 19/39 the satellite radio beacon positioning system transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
• CPC Class Codes: G01S 19/396 Determining accuracy or reliability of position or pseudorange measurements

Abstract

A method and system for navigation are provided to locate a GNSS device. The GNSS device comprises a RF front end receiving satellite signals of a plurality of satellites, and a GNSS device comprising a plurality of correlation channels each performing a correlation process to generate a correlation result from satellite signals corresponding to a satellite, a memory device for storage of the correlation results, and a processor performing acquisition and tracking based on the correlation results.

Claims

1. A power saving method for a GNSS device, comprising:

receiving satellite signals to perform a plurality of correlation processes each corresponding to a satellite;

enabling/disabling at least one correlation process based on a corresponding correlation schedule.

2. The power saving method as claimed in claim 1, further comprising:

estimating a dilution of precision based on distribution of the satellites;

acquiring position and dynamics of the GNSS device by the satellite signals; and

calculating fixed accuracy of the GNSS device based on its position.

3. The power saving method as claimed in claim 2, further comprising estimating signal qualities for each satellite.

4. The power saving method as claimed in claim 3, wherein each correlation schedule comprises a period, and a duty cycle defining how long a correlation process should be enabled within the period.

5. The power saving method as claimed in claim 4, further comprising adjusting a duty cycle of a correlation schedule based on signal quality of a corresponding satellite, dynamics of the GNSS device, the dilution of precision, and fixed accuracy of the GNSS device.

6. A GNSS device, for processing satellite signals obtained from a plurality of satellites, comprising:

a plurality of correlation channels, each performing a correlation process on the satellite signals to generate a correlation result corresponding to a satellite;

a memory device for storage of the correlation results;

a processor coupled to the memory device, performing acquisition and tracking based on the correlation results;

wherein each correlation channel is periodically turned on and turned off based on a corresponding correlation schedule.

7. The GNSS device as claimed in claim 6, wherein:

the processor estimates a dilution of precision based on distribution of the satellites;

the processor acquires position and dynamics of the GNSS device using the correlation results; and

the processor calculates fixed accuracy of the GNSS device based on the position.

8. The GNSS device as claimed in claim 7, the processor further estimates signal qualities of each satellite.

9. The GNSS device as claimed in claim 8, wherein each correlation schedule comprises a period, and a duty cycle defining how long a correlation process should be enabled within the period.

10. The GNSS device as claimed in claim 9, wherein the processor adjusts a duty cycle of a correlation schedule based on signal quality of a corresponding satellite, dynamics of the GNSS device, the dilution of precision, and fixed accuracy of the GNSS device.

11. A mobile device, comprising:

a GNSS device, for processing the satellite signals, comprising;

a plurality of correlation channels, each performing a correlation process on the satellite signals to generate a correlation result corresponding to a satellite;

a memory device for storage of the correlation results;

a processor coupled to the memory device, performing acquisition and tracking based on the correlation results;

wherein each correlation channel is periodically turned on and turned off based on a corresponding correlation schedule.

12. The mobile device as claimed in claim 11, wherein:

the processor estimates a dilution of precision based on distribution of the satellites;

the processor acquires position and dynamics of the GNSS device using the correlation results; and

the processor calculates fixed accuracy of the GNSS device based on the position.

13. The mobile device as claimed in claim 12, the processor further estimates signal qualities of each satellite.

14. The mobile device as claimed in claim 13, wherein each correlation schedule comprises a period, and a duty cycle defining how long a correlation process should be enabled within the period.

15. The mobile device as claimed in claim 14, wherein the processor adjusts a duty cycle of a correlation schedule based on signal quality of a corresponding satellite, dynamics of the GNSS device, the dilution of precision, and fixed accuracy of the GNSS device.