SATELLITE NAVIGATION RECEIVER HAVING A CONFIGURABLE ACQUISITION ENGINE

• US 20110090112A1
• Filed: 03/15/2010
• Published: 04/21/2011
• Est. Priority Date: 06/27/2007
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm Atheros Incorporated (Qualcomm, Inc.)
• Inventors: YEH, Wen-Chang, SUN, Qinfang
• Granted Patent: US 8,018,378 B2
• Time in Patent Office: Days
• US Class Current: 342/357.25
• 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 19/30 code related G01S19/246 takes precedence
• CPC Class Codes: G01S 19/36 relating to the receiver frond end
• CPC Class Codes: G01S 19/37 Hardware or software details of the signal processing chain

Abstract

A satellite navigation receiver having a flexible acquisition and tracking engine architecture. The flexible acquisition engine has a reconfigurable delay line that can be used either as a single entity or divided into different sections. Consequently, it can be configured to search different satellite vehicles, a single Doppler frequency, and full CA code in parallel. When configuring the delay line into different sections, each section is used to search a partial CA code. In this configuration, multiple Doppler mode, multiple satellite vehicles, multiple Doppler frequencies, and partial CA code can be searched in parallel. Furthermore, the different sections of the CA code can be time-multiplexed into a correlator, which can then be over clocked to achieve full CA code correlation. The flexible tracking engine includes a number of parallel tracking channels, whereby each individual channel has a number of taps or fingers, which can be used to lock onto different delays. During tracking, one of the taps can be used to lock on to the center of the peak. This leaves the other taps free to be used to perform other functions, such as determining the shape of the peak, detecting earlier arrivals for line of sight component, and obtaining an estimate of the noise floor. The flexible tracking engine is configurable to help acquisition functions, such as fine acquisition, false trigger detection, and/or fast reacquisition.

Claims

1. A satellite navigation receiver comprising:

an analog section for performing analog signal processing on a received satellite navigation signal;

an acquisition engine coupled to the analog section that acquires the satellite navigation signal;

a delay line coupled to the acquisition engine, wherein the delay line can function as a single entity and full CA code is searched and wherein the delay line can be divided into sections with each section used to search a partial CA code; and

a processor coupled to the acquisition engine that processes data from the acquisition engine to provide location information.

2. The satellite navigation receiver of claim 1, wherein the acquisition engine searches different SV'"'"'s, a single Doppler frequency, and full CA code in parallel.

3. The satellite navigation receiver of claim 1, wherein the acquisition engine searches multiple SV'"'"'s, multiple Doppler frequencies, and partial CA code in parallel.

4. The satellite navigation receiver of claim 1, wherein the acquisition engine searches multiple SV'"'"'s, multiple Doppler frequencies, and full CA code in parallel.

5. The satellite navigation receiver of claim 4, wherein portions of the full CA code is time multiplexed into a correlator and the correlator is over-clocked.

6. The satellite navigation receiver of claim 1 further comprising:

a tracking engine coupled to the analog section that tracks the satellite navigation signal, wherein the tracking engine comprises a plurality of tracking channels, each tracking channel having a configurable plurality of taps that can be used to lock on to a plurality of different delays, wherein a spacing between the taps is determined by a desired search range, wherein the tracking engine is coupled to the processor, wherein the processor processes data from the tracking engine to provide location information.

7. The satellite navigation receiver of claim 6, wherein the tracking engine performs functions that can be used to perform at least one of fine acquisition, false trigger detection, and fast reacquisition.

8. A method of determining a location of a satellite navigation receiver comprising:

receiving a navigation signal from a satellite;

performing analog signal processing on the navigation signal;

correlating the navigation signal to either a full CA code or a partial CA code, wherein a single delay line is used to correlate the navigation signal to the full CA code and a section of the delay line is used to correlate the navigation signal to the partial CA code; and

generating location information based on a correlated navigation signal.

9. The method of claim 8 further comprising correlating the navigation signal to a plurality of partial CA codes by using a plurality of sections of the delay line.

10. The method of claim 8 further comprising searching a plurality of SV'"'"'s, a plurality of Doppler frequencies, and partial CA code in parallel.

11. The method of claim 8 further comprising searching a plurality of SV'"'"'s, a plurality of Doppler frequencies, and full CA code in parallel.

12. A Global Positioning System (GPS) receiver comprising:

a means for receiving a navigation signal from a satellite;

a means for performing analog signal processing on the navigation signal;

a means for correlating the navigation signal to either a full CA code or a partial CA code, wherein a single delay line is used to correlate the navigation signal to the full CA code and a section of the delay line is used to correlate the navigation signal to the partial CA code; and

a means for generating location information based on a correlated navigation signal.

13. The GPS receiver of claim 12, wherein the means for correlating the navigational signal further comprises correlating the navigation signal to a plurality of partial CA codes by using a plurality of sections of the delay line.

14. The GPS receiver of claim 12, wherein the means for correlating the navigational signal further comprises searching a plurality of SV'"'"'s, a plurality of Doppler frequencies, and partial CA code in parallel.

15. The GPS receiver of claim 12, wherein the means for correlating the navigational signal further comprises searching a plurality of SV'"'"'s, a plurality of Doppler frequencies, and full CA code in parallel.