Validation of beacon signals

• US 7,064,708 B2
• Filed: 10/24/2003
• Issued: 06/20/2006
• Est. Priority Date: 10/24/2002
• Status: Expired due to Fees

• Current Assignee: Nokia Solutions and Networks US LLC (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Valio, Harri, Syrjarinne, Jari, Akopian, David, Pietila, Samuli
• Primary Examiner(s): PHAN, DAO LINDA
• Application Number:
  US10/693,332
• Publication Number:
  US 20040165689A1
• Time in Patent Office: 970 Days
• Field of Search: 342/357.06, 342/357.12, 342/357.15, 701/213, 701/215
• US Class Current: 342/357.58
• CPC Class Codes: G01S 19/20 Integrity monitoring, fault detection or fault isolation of space segment
• CPC Class Codes: G01S 5/02216 Timing or synchronisation of the receivers

Abstract

A method for validating detected code modulated signals transmitted by beacons of a positioning system and received by a receiver comprises as a first step performing measurements for the detected beacon signals. Then, at least one of the detected beacon signals is selected as a calibration signal. In a next step, at least one allowed range for results of measurements for detected beacon signals other than the calibration signal are determined based on measurements for the detected calibration signal and on an available reference position of the receiver. Finally, each detection of a beacon signal for which results of performed measurements are outside of an allowed range is rejected. The invention relates equally to a corresponding receiver, to an electronic device comprising such a receiver, to a device cooperating with such a receiver and to a corresponding positioning system.

Claims

1. A method for validating detected code modulated signals transmitted by beacons of a positioning system and received by a receiver of said positioning system, which beacon signals are detected based on a correlation procedure performed between a respective given code for a specific beacon and received beacon signals, said method comprising:

performing measurements for said detected beacon signals;

selecting at least one of said detected beacon signals as a calibration signal;

determining at least one allowed range for results of measurements for detected beacon signals other than said calibration signal based on measurements for said detected calibration signal and on an available reference position of said receiver; and

rejecting each detection of a beacon signal for which results of performed measurements are outside of an allowed range determined for said measurements.

2. A method according to claim 1, wherein at least the detected beacon signal with the strongest signal level is selected as calibration signal.

3. A method according to claim 1, wherein said ranges are determined based in addition on orbit parameters available for said beacons.

4. A method according to claim 1, wherein said measurements for which a range is determined comprise at least a measurement of the code phase of the detected beacon signals.

5. A method according to claim 4, wherein said code phase is determined based at least on an information on the time of transmission of a respective detected beacon signal, which information is comprised as data in said beacon signals.

6. A method according to claim 4, wherein said code phase is determined based at least on a sub component of the time of transmission of a respective detected beacon signal, which sub component is obtained by detecting regularities in said received beacon signals.

7. A method according to claim 4, wherein a range is determined for said code phase by predicting a code phase based on the code phase of said calibration signal, on an available reference position of said receiver and on available orbit parameters, and by adding and subtracting a possible error in said prediction.

8. A method according to claim 1, wherein said measurements for which a range is determined comprise a measurement indicating a frequency shift in received beacon signals due to the relative velocity between the respective beacon and said receiver.

9. A method according to claim 1, wherein said detected beacon signals are detected in a tracking process.

10. A receiver for use in a positioning system, comprising

receiving means for receiving and detecting code modulated signals transmitted by beacons of said positioning system;

and

processing means for carrying out the method according to claim 1.

11. A receiver according to claim 10, which receiver is a GPS (Global Positioning system) receiver or a Galileo receiver.

12. An electronic device comprising a receiver according to claim 10.

13. An electronic device according to claim 12, wherein said electronic device is a mobile terminal capable of connecting to a network.

14. A device for use with a positioning system, comprising

means for receiving from a receiver information on code modulated signals transmitted by beacons of a positioning system and received and detected by said receiver;

and

processing means for carrying out the method according to claim 1.

15. A device according to claim 14, which device is a network element of a network.

16. A positioning system for validating detected code modulated signals, comprising

a receiver comprising means for receiving code modulated signals transmitted by beacons, and means for providing information on received code modulated beacon signals;

and

a device according to claim 14.

17. A positioning system for validating detected code modulated signals, comprising

a receiver according to claim 10;

and

a device for providing assistance data to said receiver.

18. A positioning system according to claim 17, wherein said device is a network element of a network.