HYBRID SATELLITE POSITIONING RECEIVER

• US 20110148697A1
• Filed: 12/16/2010
• Published: 06/23/2011
• Est. Priority Date: 12/17/2009
• Status: Active Grant

• Current Assignee: U-Blox AG (u-blox Holding AG)
• Original Assignee: U-Blox AG (u-blox Holding AG)
• Inventors: Ammann, Michael, Thiel, Andreas
• Granted Patent: US 9,348,030 B2
• Time in Patent Office: Days
• US Class Current: 342/357.26
• CPC Class Codes: G01S 19/24 Acquisition or tracking or demodulation of signals transmitted by the system synchronisation aspects of direct sequence spread spectrum modulation H04B1/7073
• CPC Class Codes: G01S 19/34 Power consumption

Abstract

A satellite positioning receiver. The receiver comprises: an RF front end, for receiving satellite positioning signals; an analogue to digital converter, for sampling the received signals to generate signal samples; a memory; and a processor, for processing the signal samples to derive code-phases and pseudo-ranges and to calculate a position fix. The processor has a first mode in which it is operable to process the samples as they are generated, to calculate the position fix. It also has a second mode in which it is operable to store the samples or the code-phases or pseudo-ranges in the memory for later processing.

Claims

1. A satellite positioning receiver comprising:

an RF front end, for receiving satellite positioning signals;

an analogue to digital converter, for sampling the received signals to generate signal samples;

a memory; and

a processor, for processing the signal samples to derive code-phases and pseudo-ranges and to calculate a position fix,

the processor having a first mode in which it is operable to process the samples as they are generated, to calculate the position fix and

a second mode in which it is operable to store the samples or the code-phases or pseudo-ranges in the memory for later processing.

2. A satellite positioning receiver according to claim 1, wherein the first mode is selected in response to connection of the receiver to an external power supply.

3. A satellite positioning receiver according to claim 1, wherein the processor is adapted to:

determine whether satellite trajectory information of predetermined quality is available at the receiver;

if such trajectory information is available, select the first mode, wherein the signal samples are processed to calculate a position fix; and

if such trajectory information is unavailable, select the second mode, wherein the samples are stored in the memory for later processing.

4. The satellite positioning receiver of claim 3, wherein the processor is further adapted to, when satellite trajectory information of predetermined quality becomes available after a period of unavailability:

retrieve stored samples from the memory; and

process the samples to calculate a position fix, based on the satellite trajectory information.

5. The satellite positioning receiver of claim 3, wherein:

the analogue to digital converter is operable to sample the received signals over a predetermined interval to generate a set of samples of predetermined size; and

the processor is adapted to process the set of samples exhaustively to calculate the position fix, before any further sets of samples are processed.

6. A satellite positioning receiver according to claim 1, wherein the processor is adapted to:

process the samples as they are generated, to derive code-phase or pseudo-range data;

determine whether satellite trajectory information of predetermined quality is available at the receiver;

if such trajectory information is available, select the first mode, wherein the code-phase or pseudo-range data is further processed to calculate a position fix; and

if such trajectory information is unavailable, store the derived code-phase or pseudo-range data in the memory for later processing.

7. The satellite positioning receiver of claim 6, wherein the processor is further adapted to, when satellite trajectory information of predetermined quality becomes available after a period of unavailability:

retrieve stored code-phase or pseudo-range data from the memory; and

process the code-phase or pseudo-range data to calculate a position fix, based on the satellite trajectory information.

8. The satellite positioning receiver of claim 6, wherein the processor is adapted to deactivate the RF front-end and/or analogue to digital converter while processing the samples to derive the code-phase or pseudo-range data.

9. The satellite positioning receiver of claim 6, wherein:

the analogue to digital converter is operable to sample the received signals over a predetermined interval to generate a set of samples of predetermined size; and

the processor is adapted to process the set of samples exhaustively to derive the code-phase or pseudo-range data, before any further sets of samples are processed.

10. The satellite positioning receiver of claim 4 or claim 7, wherein the processor is further adapted to retrieve from the memory and process the stored samples or code-phase or pseudo-range data only when an external power source is detected.

11. The satellite positioning receiver of claim 1, wherein the processor is further adapted to, in the second mode, store in the memory a time-stamp associated with the stored samples or code-phase or pseudo-range data.

12. The satellite positioning receiver of claim 1, wherein the processor is further adapted to:

after samples or code-phase or pseudo-range data have been processed to calculate a position fix, store them in the memory;

when satellite trajectory information of better quality becomes available, retrieve the stored samples or code-phase or pseudo-range data from the memory; and

re-process the stored samples or code-phase or pseudo-range data to calculate a revised position fix, based on the better quality satellite trajectory information.

13. A method for a satellite positioning receiver of processing satellite positioning signals received at the receiver and sampled to generate signal samples, the method comprising:

determining whether satellite trajectory information of predetermined quality is available at the receiver;

if such trajectory information is available, processing the signal samples as they are generated, to calculate a position fix; and

if such trajectory information is unavailable, storing the signal samples in a memory for later processing.

15. A computer program comprising computer program code means adapted to, if said program is run on a computer, cause the computer to perform all the steps of claim 13 or claim 14.

16. A computer program as claimed in claim 15 embodied on a computer readable medium.

14. A method for a satellite positioning receiver of processing satellite positioning signals received at the receiver and sampled to generate signal samples, the method comprising:

processing the samples as they are generated, to derive code-phase or pseudo-range data;

determining whether satellite trajectory information of sufficient quality is available at the receiver;

if such trajectory information is available, further processing the code-phase or pseudo-range data to calculate a position fix; and

if such trajectory information is unavailable, storing the code-phase or pseudo-range data in a memory for later processing.