Arrangements for satellite-based navigation and methods therefor

• US 7,868,819 B2
• Filed: 09/05/2008
• Issued: 01/11/2011
• Est. Priority Date: 09/07/2007
• Status: Expired due to Fees

• Current Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.)
• Original Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.)
• Inventors: De Lorenzo, David, Enge, Per
• Primary Examiner(s): Tarcza; Thomas H
• Assistant Examiner(s): MCGUE, FRANK J
• Application Number:
  US12/205,521
• Publication Number:
  US 20090066574A1
• Time in Patent Office: 858 Days
• Field of Search: 342/357.12
• US Class Current: 342/357.68
• CPC Class Codes: G01S 19/21 Interference related issues ; Issues related to cross-correlation, spoofing or other methods of denial of service

Abstract

Various systems, methods and devices are implemented for processing received signals. Consistent with one such embodiment, a method is implemented for use in a signal-communication receiver having a carrier-tracking loop and a processor for operating adaptive algorithms. The method involves interpreting a received signal using space time adaptive processing (STAP). A convergence speed of the adaptive algorithms is set based on a noise bandwidth of a phase-locked loop (PLL) in the carrier-tracking loop. A carrier-phase de-rotation constraint is implemented into weight parameters of the STAP to preserve spatial and temporal degrees of freedom in the STAP.

Claims

1. For use in a signal-communication receiver having a carrier-tracking loop and a processor for operating adaptive algorithms, a method for interpreting a received signal using space time adaptive processing (STAP), the method comprising at least one of:

setting a convergence speed of the adaptive algorithms based on a noise bandwidth of a phase-locked loop (PLL) in the carrier-tracking loop; and

implementing a carrier-phase de-rotation constraint into weight parameters of the STAP to preserve spatial and temporal degrees of freedom in the STAP.

2. The method of claim 1, wherein the method further includes the other of the steps of setting and implementing and the received signal is a signal from a global positioning system (GPS) satellite.

3. The method of claim 1, wherein the carrier-phase de-rotation constraint is such that a weight parameter applied to a central time-tap on a master antenna element is constrained to zero degrees of phase.

4. The method of claim 1, wherein the convergence speed is set to provide an expected convergence speed of the STAP that is a function of a number of corrupted carrier-phase discriminator output values necessary to cause a cycle slip.

5. The method of claim 1, wherein the method incorporates adaptive antenna array processing using two separate feedback mechanisms that alter the phase difference between an incoming satellite signal and a carrier numeric controlled oscillator (NCO).

6. The method of claim 5, wherein the two separate feedback mechanisms include a carrier tracking loop and the complex coefficients of an antenna weight vector.

7. A signal-communication receiver having a carrier-tracking loop and a processor operating adaptive algorithms for interpreting a received signal using space time adaptive processing (STAP), the receiver comprising:

a processing block that performs at least one of;

implementing the adaptive algorithms using a convergence speed that is based on a noise bandwidth of a phase-locked loop (PLL) in the carrier-tracking loop and

implementing a carrier-phase de-rotation constraint into weight parameters of the STAP to preserve spatial and temporal degrees of freedom in the STAP.

8. The receiver of claim 7, wherein the processing block further performs the other of setting and implementing and the received signal is a signal from a global positioning system (GPS) satellite.

9. The receiver of claim 7, wherein the carrier-phase de-rotation constraint is such that the weight parameter, as applied to a central time-tap on a master antenna element, is constrained to zero degrees of phase.

10. The receiver of claim 7, wherein the convergence speed is set to provide an expected convergence speed of the STAP that is a function of a number of corrupted carrier-phase discriminator output values necessary to cause a cycle slip.

11. The receiver of claim 7, wherein the processing block incorporates adaptive antenna array processing using two separate feedback mechanisms that alter the phase difference between an incoming satellite signal and a carrier numeric controlled oscillator (NCO).

12. The receiver of claim 11, wherein the two separate feedback mechanisms include a carrier tracking loop and the complex coefficients of an antenna weight vector.

13. A computer-readable storage medium, for use in a signal-communication receiver having a carrier-tracking loop and a processor for operating adaptive algorithms, configured with software that when executed by a processor implements a method for interpreting a received signal using space time adaptive processing (STAP), the method comprising at least one of:

setting a convergence speed of the adaptive algorithms based on a noise bandwidth of a phase-locked loop (PLL) in the carrier-tracking loop; and

implementing a carrier-phase de-rotation constraint into weight parameters of the STAP to preserve spatial and temporal degrees of freedom in the STAP.

14. The storage medium of claim 13, wherein the received signal is a signal from a global positioning system (GPS) satellite.

15. The storage medium of claim 13, wherein the carrier-phase de-rotation constraint is such that the weight parameter, as applied to a central time-tap on a master antenna element, is constrained to zero degrees of phase.

16. The storage medium of claim 13, wherein the convergence speed is set to provide an expected convergence speed of the STAP that is a function of a number of corrupted carrier-phase discriminator output values necessary to cause a cycle slip.

17. The storage medium of claim 13, wherein the method incorporates adaptive antenna array processing using two separate feedback mechanisms that alter the phase difference between an incoming satellite signal and a carrier numeric controlled oscillator (NCO).

18. The storage medium of claim 17, wherein the two separate feedback mechanisms include a carrier tracking loop and the complex coefficients of an antenna weight vector.