Method and apparatus for determining the geographic location of a device

• US 7,948,435 B2
• Filed: 03/04/2010
• Issued: 05/24/2011
• Est. Priority Date: 09/22/2006
• Status: Expired due to Fees

• Current Assignee: TeleCommunication Systems Inc (Comtech Telecommunications Corporation)
• Original Assignee: Andrew LLC (CommScope Holding Company, Inc.)
• Inventors: Nicholson, Peter, Harper, Neil
• Primary Examiner(s): Tarcza, Thomas H
• Assistant Examiner(s): LIU, HARRY K
• Application Number:
  US12/717,233
• Publication Number:
  US 20100156704A1
• Time in Patent Office: 446 Days
• Field of Search: 342/357.67, 342/357.43
• US Class Current: 342/357.67
• CPC Class Codes: G01S 19/20 Integrity monitoring, fault detection or fault isolation of space segment
• CPC Class Codes: G01S 19/23 Testing, monitoring, correcting or calibrating of receiver elements
• CPC Class Codes: G01S 19/40 Correcting position, velocity or attitude

Abstract

A method and apparatus for determining the location of a device from signals provided by a plurality of satellites. A device receives a first plurality of signals comprising one signal from each of a first plurality of satellites and determines a first location of the device as a function of the first plurality of signals. The device then determines a second location thereof as a function of a second plurality of signals if the first location is not within a predetermined threshold. The second plurality of signals is a first subset of the first plurality of signals.

Claims

1. A method for determining the location of a device comprising the steps of:

(a) receiving a plurality of signals from a plurality of satellites;

(b) generating estimates of a location of the device using each different combination of the plurality of signals while leaving out N signal from the received signals; and

(c) selecting an estimate as defined by a quality of each of the combinations,

wherein N is a positive integer.

2. The method of claim 1 wherein a cardinality of the plurality of signals is at least four.

3. The method of claim 1 wherein the satellites are part of a Global Navigation Satellite System (“

GNSS”

).

4. The method of claim 3 wherein the GNSS is selected from the group consisting of:

Global Positioning System (“

GPS”

), Galileo, GLONASS, and Quasi-Zenith Satellite System (“

QZSS”

).

5. The method of claim 1 wherein the quality is a function of a sum of the squared residuals.

6. The method of claim 1 wherein the device is a mobile unit.

7. The method of claim 6 wherein the mobile unit is selected from the group consisting of:

cellular telephone, text messaging device, computer, portable computer, vehicle locating device, vehicle security device, communication device, and wireless transceiver.

8. The method of claim 6 wherein the mobile unit receives signals from a cellular network.

9. The method of claim 8 wherein the estimate of a location of the device is a function of signals provided by the cellular network.