High sensitivity satellite positioning system receiver

• US 8,730,101 B2
• Filed: 05/13/2010
• Issued: 05/20/2014
• Est. Priority Date: 05/13/2010
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Shah, Mayur N., Riley, Wyatt Thomas, Farmer, Dominic Gerard
• Primary Examiner(s): LIU, HARRY K
• Application Number:
  US12/779,755
• Publication Number:
  US 20110279317A1
• Time in Patent Office: 1,468 Days
• Field of Search: 342/357.64
• US Class Current: 342/357.64
• CPC Class Codes: G01S 19/235 Calibration of receiver components
• CPC Class Codes: G01S 19/246 involving long acquisition integration times, extended snapshots of signals or methods specifically directed towards weak signal acquisition
• CPC Class Codes: G01S 19/26 involving a sensor measurement for aiding acquisition or tracking

Abstract

An attenuated satellite positioning system (SPS) signal is acquired using long integration over multiple navigation data bits. To produce a stable internal clock signal to perform the long integration, an external clock signal is received from a highly stable source, such as a wireless communication base station or a nearby femtocell. An internal oscillator is driven at a desired frequency that is aligned with the scaled frequency of the external clock signal to produce the stable internal clock signal. The SPS signal is received and integrated for an extended period using the internal clock signal. Predicted SPS data may be received from an external source and used to perform coherent integration. Alternatively, non-coherent integration may be performed. Additionally, a motion sensor may be used to determine if there is motion relative to the external clock source or to compensate for Doppler errors in the external clock signal due to motion.

Claims

1. A method of acquiring a satellite positioning system (SPS) signal with a substantially stationary or semi-stationary device, the method comprising:

receiving an external clock signal at the substantially stationary or semi-stationary device through a wired interface;

driving an oscillator to a desired frequency that is aligned with a scaled frequency of the external clock signal to generate an internal clock signal;

receiving an SPS signals;

receiving predicted SPS data comprising SPS sensitivity assistance data through the wired interface; and

integrating the received SPS signal over multiple navigation data bits using the internal clock signal to acquire the SPS signal, wherein the received SPS signal is coherently integrated using the received predicted SPS data.

2. The method of claim 1, wherein the received predicted SPS data includes a predicted value of navigation data bits in the SPS data, the method further comprising performing a data wipe-off of the received SPS signal using the predicted value of the navigation data bits.

3. The method of claim 1, wherein the predicted SPS data is received through an Ethernet backhaul.

4. A substantially stationary or semi-stationary device comprising:

a satellite positioning system (SPS) signal receiver that provides positioning data for the substantially stationary or semi-stationary device;

a wired interface that receives an external clock signal;

an internal clock;

a frequency controller coupled to the internal clock and the wired interface, the frequency controller driving the internal clock to a desired frequency that is aligned with a scaled frequency of the external clock signal;

a processor connected to the SPS signal receiver and the wired interface, and configured to receive a signal from the internal clock;

memory connected to the processor; and

software held in the memory and run in the processor to cause the processor to integrate a received SPS signal over multiple navigation data bits using the internal clock at the desired frequency, wherein predicted SPS data comprising SPS sensitivity assistance data is received by the wired interface that is coupled to the processor, the software further causes the processor to coherently integrate the received SPS signal using the predicted SPS data.

5. The device of claim 4, wherein the predicted SPS data includes a predicted value of navigation data bits in the SPS data, the software further causes the processor to perform a data wipe-off of the received SPS signal using the predicted value of the navigation data bits.

6. The device of claim 4, wherein the frequency controller is a phase-locked loop.

7. A substantially stationary or semi-stationary device comprising:

means for receiving an external clock signal at the substantially stationary or semi-stationary device through a wired interface;

means for driving an internal oscillator to a desired frequency that is aligned with a scaled frequency of the external clock signal to generate an internal clock signal;

means for receiving a satellite positioning system (SPS) signal;

means for receiving predicted SPS data comprising SPS sensitivity assistance data through the wired interface; and

means for integrating the received SPS signal over multiple navigation data bits using the internal clock signal to acquire the SPS signal, wherein the received SPS signal is coherently integrated using the received predicted SPS data.

8. The system of claim 7, further comprising means for performing a data wipe-off of the received SPS signal using the predicted SPS data.

9. A computer-readable storage medium including program code stored thereon, comprising:

program code to integrate a received SPS signal over multiple navigation data bits using an internal clock that is driven at a desired frequency based on an external clock signal received through a wired communication interface of a substantially stationary or semi-stationary device, wherein the received SPS signal is coherently integrated using received predicted SPS data comprising SPS sensitivity assistance data.

10. A method of acquiring a satellite positioning system (SPS) signal with a substantially stationary or semi-stationary device, the method comprising:

receiving an external clock signal with the substantially stationary or semi-stationary device via a wired communication interface;

using the external clock signal to generate an internal clock signal;

receiving an SPS signals;

receiving predicted SPS data comprising SPS sensitivity assistance data via the wired communication interface; and

integrating the received SPS signal over multiple navigation data bits using the internal clock signal to acquire the SPS signal, wherein the received SPS signal is coherently integrated using the received predicted SPS data.

11. The method of claim 10, wherein the received predicted SPS data includes a predicted value of navigation data bits in the SPS data, the method further comprising performing a data wipe-off of the received SPS signal using the predicted value of the navigation data bits.

12. The method of claim 10, wherein the external clock signal and the predicted SPS data are received through an Ethernet backhaul.

13. The method of claim 10, wherein the external clock signal is a NTP/PTP (network time protocol, precise time protocol) signal delivered over an Ethernet backhaul.

21. The method of claim 10, wherein using the external clock signal to generate the internal clock signal comprises driving an oscillator to a desired frequency that is aligned with a scaled frequency of the external clock signal to generate the internal clock signal.

14. A substantially stationary or semi-stationary device comprising:

a satellite positioning system (SPS) signal receiver that provides positioning data at the substantially stationary or semi-stationary device;

a wired communication interface that receives an external clock signal;

a controller coupled to the wired communication interface, the controller generating an internal clock signal based on the external clock signal;

a processor connected to the SPS signal receiver and the wired communication interface, and configured to receive the internal clock signal;

memory connected to the processor; and

software held in the memory and run in the processor to cause the processor to integrate a received SPS signal over multiple navigation data bits using the internal clock signal, wherein predicted SPS data comprising SPS sensitivity assistance data is received by the wired communication interface that is coupled to the processor, the software further causes the processor to coherently integrate the received SPS signal using the predicted SPS data.

15. The device of claim 14, wherein the predicted SPS data includes a predicted value of navigation data bits in the SPS data, the software further causes the processor to perform a data wipe-off of the received SPS signal using the predicted value of the navigation data bits.

16. The device of claim 14, wherein the controller comprises a frequency controller that is a phase-locked loop coupled to an internal clock, wherein the frequency controller drives the internal clock to a desired frequency that is aligned with a scaled frequency of the external clock signal to produce the internal clock signal.

17. The device of claim 14, wherein the external clock signal is a NTP/PTP (network time protocol, precise time protocol) signal delivered over an Ethernet backhaul.

18. A substantially stationary or semi-stationary device comprising:

means for receiving an external clock signal at the substantially stationary or semi-stationary device over an Ethernet backhaul;

means for using the external clock signal to generate an internal clock signal;

means for receiving a satellite positioning system (SPS) signal;

means for receiving predicted SPS data comprising SPS sensitivity assistance data over the Ethernet backhaul; and

means for integrating the received SPS signal over multiple navigation data bits using the internal clock signal to acquire the SPS signal, wherein the received SPS signal is coherently integrated using the received predicted SPS data.

19. The system of claim 18, further comprising means for performing a data wipe-off of the received SPS signal using the predicted SPS data.

20. A computer-readable storage medium including program code stored thereon, comprising:

program code to integrate a received SPS signal over multiple navigation data bits using an internal clock that is generated based on an external clock signal received over an Ethernet backhaul of a substantially stationary or semi-stationary device, wherein the received SPS signal is coherently integrated using received predicted SPS data comprising SPS sensitivity assistance data received over the Ethernet backhaul.