Method and Apparatus for a GPS Receiver Capable or Reception of GPS Signals and Binary Offset Carrier Signals

• US 20100134354A1
• Filed: 12/02/2008
• Published: 06/03/2010
• Est. Priority Date: 12/02/2008
• Status: Active Grant

• Current Assignee: CSR Technology Incorporated (Qualcomm, Inc.)
• Original Assignee: SIRF Technology Incorporated (Qualcomm, Inc.)
• Inventors: Lennen, Gary
• Granted Patent: US 7,994,977 B2
• Time in Patent Office: Days
• US Class Current: 342/357.730
• CPC Class Codes: G01S 19/33 Multimode operation in different systems which transmit time stamped messages, e.g. GPS/GLONASS

Abstract

A system and method capable of mitigating the migration from the current GPS system to the Galileo system and allow a single satellite system positioning receiver to process both GPS signals and Galileo signals.

Claims

1. A global positioning system (GPS) and Galileo system device, comprising:

an input sample memory for receipt of 4fo digital signal samples of a positioning signal in a first mode or 16fo digital signal samples from a digital mixer in a second mode;

a carrier generator for generation a 1023 chip spreading code when 4fo digital signal samples of a GPS signals are received and 4092 chip spreading code when 16fo digital signal samples of a Galileo signal are received;

a match filter configurable for at list a ½

chip and ¼

chip match filter that match the spreading code with the digital samples from the digital sample memory;

a coherent memory to store the filtered data from the match filter;

a non-coherent memory for storage of non-coherent data that results from application of a fast Fourier transform to the filtered data; and

a peak detector that detects data peaks by sorting the non-coherent data in the non-coherent memory and storing the detected peaks in a peak memory, where the peaks indicate the presence of a signal from a satellite vehicle.

2. The GPS and Galileo system device of claim 1, further comprising a binary offset carrier (BOC) signal as the positioning signal received at the digital mixer when the device is in the second mode.

3. The GPS and Galileo system device of claim 2, where the match filter as a ¼

chip match filter.

4. The GPS and Galileo system device of claim 2, where the coherent memory is larger in the second mode relative to the first mode.

5. The GPS and Galileo system device of claim 2, where the non-coherent memory is larger in the second mode relative to the first mode.

6. The GPS and Galileo system device of claim 2, where the satellite vehicle is a Galileo satellite.

7. The GPS and Galileo system device of claim 2, including:

a 3fo carrier mixed with the 16fo digital samples by the digital mixer resulting in a digital samples that are stored in the input sample memory;

a short code generator that generates a portion of a spreading code that is used by the ½

chip match filter to generate filtered data that is stored in the coherent memory during acquisition of a side lobe of a Galileo positioning signal.

8. The GPS and Galileo system device of claim 7, further including a 5fo carrier mixed with the 16fo digital samples by the digital mixer resulting both digital samples stored in a 3fo input sample memory and a 5fo input sample memory that is further processed by the matched filter resulting in filtered data stored in the coherent memory during acquisition of both side lobes of a Galileo position signal.

9. The GPS and Galileo system device of claim 2, including:

a 5fo carrier mixed with the 16fo digital samples by the digital mixer resulting in a digital samples that are stored in the input sample memory;

a short code generator that generates a portion of a spreading code that is used by the ½

chip match filter to generate filtered data that is stored in the coherent memory during acquisition of a side lobe of a Galileo positioning signal.

10. The GPS and Galileo system device of claim 9, further including a 3fo carrier mixed with the 16fo digital samples by the digital mixer resulting both digital samples stored in a 3fo input sample memory and a 5fo input sample memory that is further processed by the matched filter resulting in filtered data stored in the coherent memory during acquisition of both side lobes of a Galileo position signal.

11. The GPS and Galileo system device of claim 1, further including,

a start mode with the input sample memory adapted to store input samples from a GPS positioning signal that are processed by the match filter that employs a GPS dispreading code in determining if a GPS satellite vehicle has been acquired and the match filter being configured to process input samples from a BOC signal in response to acquisition of the GPS satellite.

12. A method for processing GPS and BOC positioning signals in a satellite positioning device, comprising:

configuring a match filter, input sample memory and code generator in the satellite positioning device for processing the GPS positioning signal;

determining if signal samples of the GPS positioning signals from the input sample memory match a dispreading code generated by the code generator with the match filter that results in filtered signal data;

storing the filtered data in a coherent memory;

transforming the filtered data from the coherent memory with a fast Fourier transform and saving the transformed data in a non-coherent memory; and

peak sorting the transformed data to detect if a GPS satellite has been acquired;

reconfiguring the match filter, input sample memory and code generator in the satellite positing device for processing both the GPS positioning signal and the BOC positioning signal.

13. The method of claim 12, where reconfiguring the input sample memory includes configuring the input sample memory to store 16fo samples of positioning samples.

14. The method of claim 12 where reconfiguring the match filter includes configuring the match filter as a ⅛

^th chip match filter.

15. The method of claim 12 where reconfiguring the code generate includes reconfiguring the code generator to generate BOC dispreading codes.

16. The method of claim 12 further includes increasing the size of a coherent memory when reconfiguring the positioning device for BOC positioning signals.

17. A computer readable medium having computer readable code means embodied therein for execution by a GPS device for processing GPS and BOC positioning signals, comprising:

code means for configuring a match filter, input sample memory and code generator in the satellite positioning device for processing the GPS positioning signal;

code means for determining if signal samples of the GPS positioning signals from the input sample memory match a dispreading code generated by the code generator with the match filter that results in filtered signal data;

code means for storing the filtered data in a coherent memory;

code means for transforming the filtered data from the coherent memory with a fast Fourier transform and saving the transformed data in a non-coherent memory; and

code means for peak sorting the transformed data to detect if a GPS satellite has been acquired;

code means for reconfiguring the match filter, input sample memory and code generator in the satellite positing device for processing both the GPS positioning signal and the BOC positioning signal.

18. The computer readable medium of claim 17, where the code means for reconfiguring the input sample memory includes code means for configuring the input sample memory to store 16fo samples of positioning samples.

19. The computer readable medium of claim 17 where code means for reconfiguring the match filter includes code means for configuring the match filter as a ⅛

^th chip match filter.

20. The computer readable medium of claim 17 where code means for reconfiguring the code generate includes code means for reconfiguring the code generator to generate BOC dispreading codes.

21. The computer readable medium of claim 17 further includes code means for increasing the size of a coherent memory when reconfiguring the positioning device for BOC positioning signals.