Method for detecting navigation beacon signals using two antennas or equivalent thereof

• US 7,859,461 B2
• Filed: 04/04/2008
• Issued: 12/28/2010
• Est. Priority Date: 05/11/2005
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Jalali, Ahmad, Wengler, Michael James
• Primary Examiner(s): PHAN, DAO LINDA
• Application Number:
  US12/098,323
• Publication Number:
  US 20080186230A1
• Time in Patent Office: 998 Days
• Field of Search: 342/378, 342/382, 342/383, 342/434
• US Class Current: 342/378
• CPC Class Codes: G01S 19/21 Interference related issues ; Issues related to cross-correlation, spoofing or other methods of denial of service
• CPC Class Codes: G01S 19/36 relating to the receiver frond end
• CPC Class Codes: G01S 2013/466 by Trilateration, i.e. two antennas or two sensors determine separately the distance to a target, whereby with the knowledge of the baseline length, i.e. the distance between the antennas or sensors, the position data of the target is determined
• CPC Class Codes: G01S 5/0215 Interference
• CPC Class Codes: H04B 7/0854 using error minimizing algorithms, e.g. minimum mean squared error [MMSE], "cross-correlation" or matrix inversion

Abstract

A method for detecting a plurality of navigation beacon signals by using either two antennas or a synthetic aperture antenna for receiving a plurality of distinct measurements, and combining the plurality of distinct measurements using a plurality of antenna weight components to form an interference cancellation beam. In one embodiment, the plurality of antenna weight components is determined by eigenvalue processing. In another embodiment, the plurality of antenna weight components is determined by simplified processing. In another aspect, a single antenna is used for receiving an originally received measurement. A copy of the originally received measurement is made and processed to achieve the proper time delay to emulate spatial diversity. The originally received measurement and the processed copy are combined to form an interference cancellation beam.

Claims

1. A method for detecting a plurality of navigation beacon signals, the method comprising:

receiving, at a mobile receiver, a first navigation beacon signal measurement from a base station;

receiving, at the mobile receiver, a distinct second navigation beacon signal measurement from the base station; and

combining the first navigation beacon signal measurement with the distinct second navigation beacon signal measurement based on two antenna weight components to form an interference cancellation beam.

2. The method of claim 1 wherein the two antenna weight components are determined by eigenvalue processing.

3. The method of claim 1 wherein the two antenna weight components are determined by simplified processing.

4. The method of claim 3 wherein each of the two antenna weight components comprises a complex voltage of a strongest navigation beacon signal.

5. The method of claim 3 wherein each of the two antenna weight components comprises the sum of complex voltages of a plurality of strongest navigation beacon signals.

6. The method of claim 1 wherein the first navigation beacon signal measurement is determined from a first signal received at a first antenna, and the distinct second navigation beacon signal measurement is determined from a distinct second signal received at a spatially diverse second antenna.

7. The method of claim 1 wherein the first navigation beacon signal measurement is determined from a first signal received at an antenna during a first time period, and the distinct second navigation beacon signal measurement is determined from a distinct second signal received at the antenna during a distinct second time period.

8. The method of claim 1 wherein the first navigation beacon signal measurement is determined from a copy of a previously received navigation beacon signal.

9. The method of claim 8 wherein the previously received navigation beacon signal comprises a previously received strongest navigation beacon signal.

10. The method of claim 1 wherein the first navigation beacon signal measurement comprises a base station pilot signal measurement.

11. A mobile wireless communication apparatus configured to detect a plurality of navigation beacon signals, the apparatus comprising:

an antenna system;

a transceiver system coupled to the antenna system and configured to receive, via the antenna system, a first navigation beacon signal measurement from a base station, and a distinct second navigation beacon signal measurement from the base station; and

a processor configured to combine the first navigation beacon signal measurement with the distinct second navigation beacon signal measurement based on two antenna weight components to form an interference cancellation beam;

wherein the antenna system is contained within the mobile wireless communication apparatus.

12. The apparatus of claim 11, wherein the antenna system comprises:

a first antenna configured to provide a first navigation beacon signal to the transceiver system; and

a spatially diverse second antenna configured to provide a second navigation beacon signal to the transceiver system.

13. The apparatus of claim 11, wherein the antenna system comprises a synthetic aperture antenna, and wherein the transceiver system is configured to receive, from the synthetic aperture antenna, the first navigation signal measurement at a time distinct from a time that the transceiver system receives the distinct second navigation beacon signal measurement.

14. The apparatus of claim 11, wherein the transceiver system is configured to receive, as the first navigation signal measurement, a pilot signal measurement from the base station.

15. The apparatus of claim 11, wherein the transceiver system comprises a mobile user transceiver system.

16. The apparatus of claim 11, wherein the processor is configured to determine the two antenna weight components based on eigenvalue processing.

17. The apparatus of claim 11, wherein the processor is configured to determine the two antenna weight components to cancel a strongest navigation beacon signal.

18. The apparatus of claim 11, wherein the processor is configured to determine a complex weight for each of the two antenna weight components.

19. An apparatus configured to detect a plurality of navigation beacon signals, the apparatus comprising:

means for receiving, at a mobile receiver, a first navigation beacon signal measurement from a base station;

means for receiving, at the mobile receiver, a distinct second navigation beacon signal measurement from the base station; and

means for combining the first navigation beacon signal measurement with the distinct second navigation beacon signal measurement based on two antenna weight components to form an interference cancellation beam.

20. A computer readable medium in a mobile wireless communication device, the computer readable medium being encoded with computer executable instructions for:

determining a first antenna weight component;

determining a second antenna weight component; and

combining a first navigation beacon signal measurement received from a base station with a distinct second navigation beacon signal measurement received from the base station based on the first and second antenna weight components to form an interference cancellation beam.