NAVIGATION RECEIVER

• US 20090160704A1
• Filed: 12/20/2007
• Published: 06/25/2009
• Est. Priority Date: 12/20/2007
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Conflitti, Paul A., ZHAO, LIANG, Sheynblat, Leonid, Kohlmann, Michael, Rowitch, Douglas, Conroy, Cormac S., Brockenbrough, Roger
• Granted Patent: US 8,044,853 B2
• Time in Patent Office: Days
• US Class Current: 342/357.290
• CPC Class Codes: G01S 19/25 involving aiding data received from a cooperating element, e.g. assisted GPS
• CPC Class Codes: G01S 19/32 Multimode operation in a single same satellite system, e.g. GPS L1/L2
• CPC Class Codes: G01S 19/33 Multimode operation in different systems which transmit time stamped messages, e.g. GPS/GLONASS
• CPC Class Codes: G01S 19/36 relating to the receiver frond end

Abstract

The subject matter disclosed herein relates to a system and method for processing navigation signals received from multiple global navigation satellite systems (GNSS′). In a particular implementation, signals received from multiple GNSS′ may be processed in a single receiver channel.

Claims

1. A method comprising:

receiving two or more satellite positioning system (SPS) signals at a receiver at an associated two or more carrier frequencies; and

downconverting said two or more received SPS signals in a single receiver path according to a common local oscillator frequency.

2. The method of claim 1, wherein an image portion of a first down converted signal substantially overlaps a desired portion of a second downconverted signal.

3. The method of claim 1, wherein at least a first one of said SPS signals is transmitted from a first global navigation satellite system (GNSS) and a second one of said SPS signals is transmitted from a second GNSS.

4. The method of claim 3, wherein said first SPS signal is transmitted from a Glonass GNSS, and wherein said second SPS signal is transmitted from an SPS selected from the group consisting essentially of a GPS GNSS and a Galileo GNSS.

5. The method of claim 1, wherein said downconverting further comprises mixing said two or more received SPS signals with a local oscillator signal having said common local oscillator frequency, wherein said common local oscillator frequency is selected to be about midway between first and second carrier frequencies associated with two of said received SPS signals.

6. The method of claim 1, wherein said downconverting further comprises mixing said received SPS signals with a local oscillator to provide in-phase and quadrature components, and wherein the method further comprises:

digitally sampling said in-phase and quadrature components to provide sampled in-phase and quadrature components;

applying a first second-stage downconversion to said sampled in-phase and quadrature components to provide output samples for baseband processing according to a first Global Navigation Satellite System (GNSS); and

applying a second second-stage downconversion to said sampled in-phase and quadrature components to provide output samples for baseband processing according to said second GNSS.

7. The method of claim 1, wherein said downconverting further comprises mixing said received SPS signals with a local oscillator to provide in-phase and quadrature components, and wherein the method further comprises:

applying a first second-stage downconversion to said in-phase and quadrature components to provide first downconverted in-phase and quadrature components for processing according to a first Global Navigation Satellite System (GNSS);

applying a second second-stage downconversion to said in-phase and quadrature components to provide second downconverted in-phase and quadrature components for processing according to a second GNSS; and

digitally sampling said first and second downconverted in-phase and quadrature components to provide sampled in-phase and quadrature components for baseband processing.

8. The method of claim 1, wherein said two or more SPS signals are received through a single antenna and single bandpass filter adapted to receive SPS signals over a band including said carrier frequencies.

9. The method of claim 8, wherein said bandpass filter comprises a surface acoustic wave (SAW) filter.

10. The method of claim 8, wherein said first and second SPS signals are received through a single low noise amplifier (LNA).

13. The mobile station of claim 8, wherein said second receiver further comprises a bandpass filter adapted to receive said two or more SPS signals over a band including said carrier frequencies associated with said two or more SPS signals.

14. The mobile station of claim 13, wherein said bandpass filter comprises a single surface acoustic wave (SAW) filter.

11. A mobile station comprising:

a first receiver adapted to receive information over terrestrial wireless links, said receiver being further adapted to receive acquisition assistance (AA) information, and

a second receiver adapted to receive two or more satellite positioning system (SPS) signals at an associated two or more carrier frequencies, the second receiver comprising;

a circuit to downconvert said two or more received SPS signals in a single receiver path according to a common local oscillator frequency; and

a baseband processor to determine pseudorange measurements associated with said received SPS signals based, at least in part, on said downconverted signals and said AA information.

12. The mobile station of claim 11, wherein an image portion of a first downconverted signal substantially overlaps a desired portion of a second downconverted signal.

15. A complex mixing circuit adapted to downconvert first and second intermediate frequency (IF) signals to associated first and second baseband signals, the complex mixing circuit comprising:

four multipliers to combine said first and second IF signals with a local oscillator to provide an associated four multiplier output signals;

a first pair adders to provide said first baseband signal based, at least in part, on said four multiplier output signals; and

a second pair of adders to provide said second baseband signal based, at least in part, on said four multiplier output signals.

16. A receiver comprising:

a low noise amplifier adapted to simultaneously receive a plurality of SPS signals originating at a plurality of associated global navigation satellite systems (GNSS′

); and

a common complex signal path to process said simultaneously received SPS signals, said complex signal path comprising;

a mixer adapted to generate in-phase and quadrature signal paths based, at least in part, on said received SPS signals; and

one or more analog to digital conversion (ADC) circuits adapted to provide sampled in-phase and quadrature components based, at least in part, on signals processed in said in-phase and quadrature signal paths.

17. The receiver of claim 16, and further comprising a complex downconversion circuit adapted to generate a plurality of downconverted in-phase and quadrature signal paths for baseband processing according to said plurality of associated GNSS′

.

18. The receiver of claim 17, wherein said complex downconversion circuit is adapted to generate said downconverted in-phase and quadrature signal paths based, at least in part, on said sampled in-phase and quadrature components.

19. The receiver of claim 17, wherein said one or more ADC circuits are adapted to generate said sampled in-phase and quadrature components based, at least in part on signals in said plurality of downconverted in-phase and quadrature signal paths.

20. The receiver of claim 17, wherein said one or more ADC circuits comprise a first ADC circuit adapted to sample signals transmitted in said in-phase signal path and a second ADC adapted to sample signals transmitted in said quadrature signal path.

21. The receiver of claim 17, wherein said one or more ADC circuits comprise a single complex ADC circuit.

22. The receiver of claim 17, wherein said one or more ADC circuits comprise a single ADC circuit adapted to obtain time-multiplexed samples of signals in said in-phase and quadrature signal paths.

23. An apparatus comprising:

means for receiving two or more satellite positioning system (SPS) signals at a receiver at an associated two or more carrier frequencies, and

means for downconverting said two or more received SPS signals in a single receiver path according to a common local oscillator frequency.

24. The apparatus of claim 23, wherein said means for downconverting further comprises means for mixing said received SPS signals with a local oscillator to provide in-phase and quadrature components, and wherein the apparatus further comprises:

means for digitally sampling said in-phase and quadrature components to provide sampled in-phase and quadrature components;

means for applying a first second-stage downconversion to said sampled in-phase and quadrature components to provide output samples for baseband processing according to a first Global Navigation Satellite System (GNSS); and

means for applying a second second-stage downconversion to said sampled in-phase and quadrature components to provide output samples for baseband processing according to said second GNSS.

25. The apparatus of claim 23, wherein said means for downconverting further comprises means for mixing said received SPS signals with a local oscillator to provide in-phase and quadrature components, and wherein the apparatus further comprises:

means for applying a first second-stage downconversion to said in-phase and quadrature components to provide first downconverted in-phase and quadrature components for processing according to a first Global Navigation Satellite System (GNSS);

means for applying a second second-stage downconversion to said in-phase and quadrature components to provide second downconverted in-phase and quadrature components for processing according to a second GNSS; and

means for digitally sampling said first and second downconverted in-phase and quadrature components to provide sampled in-phase and quadrature components for baseband processing.

26. The apparatus of claim 23, wherein said means for downconverting further comprises means for mixing said two or more received SPS signals with a local oscillator signal having a said local oscillator frequency, wherein said local oscillator frequency is selected to be about midway between first and second carrier frequencies associated with two of said received SPS signals.

27. A mobile station comprising:

a first receiver adapted to receive information over terrestrial wireless links, said receiver being further adapted to receive acquisition assistance (AA) information; and

a second receiver comprising;

a low noise amplifier adapted to simultaneously receive a plurality of SPS signals originating at a plurality of associated global navigation satellite systems (GNSS′

);

a common complex signal path to process said simultaneously received SPS signals, said complex signal path comprising a mixer adapted to generate in-phase and quadrature signal paths based, at least in part, on said received SPS signals; and

one or more analog to digital conversion (ADC) circuits adapted to provide sampled in-phase and quadrature components based, at least in part, on signals processed in said in-phase and quadrature signal paths; and

a baseband processor to determine pseudorange measurements associated with said received SPS signals based, at least in part, on said downconverted signals and said AA information.