Method and apparatus for navigation systems

• US 8,717,235 B2
• Filed: 03/05/2012
• Issued: 05/06/2014
• Est. Priority Date: 02/28/2006
• Status: Active Grant

• Current Assignee: Nokia Corporation
• Original Assignee: Nokia Corporation
• Inventors: Alanen, Kimmo, Syrjarinne, Jari
• Primary Examiner(s): Issing, Gregory C
• Application Number:
  US13/412,186
• Publication Number:
  US 20120206298A1
• Time in Patent Office: 792 Days
• Field of Search: 342/357.58, 342/357.64, 342/357.72
• US Class Current: 342/357.58
• CPC Class Codes: G01S 19/05 providing aiding data
• CPC Class Codes: G01S 19/08 providing integrity information, e.g. health of satellites or quality of ephemeris data
• CPC Class Codes: G01S 19/20 Integrity monitoring, fault detection or fault isolation of space segment
• CPC Class Codes: G01S 19/25 involving aiding data received from a cooperating element, e.g. assisted GPS
• CPC Class Codes: G01S 19/32 Multimode operation in a single same satellite system, e.g. GPS L1/L2

Abstract

The invention relates to a network element comprising a controlling element for forming assistance data relating to two or more signals transmitted by a reference station of at least one navigation system; and a transmitter for transmitting the assistance data via a communications network to a device. The device comprises a positioning receiver for performing positioning on the basis of two or more signals transmitted by a reference station of the at least one satellite navigation system; a receiver for receiving the assistance data from the network element; and an examining element configured to examine the received assistance data to find out information relating to the status of the two or more signals. The information comprises indication on the reference station the signal relates to, and the status indicates the usability of the signal.

Claims

1. A device comprising:

a positioning receiver for performing positioning on the basis of two or more different satellite-positioning signals transmitted by a same reference station of at least one satellite navigation system, the different satellite-positioning signals being specifiable by different signal identities;

a receiver for receiving assistance data relating to said at least one navigation system; and

an examining element adapted to examine the received assistance data;

wherein said examining element is adapted to examine the assistance data to find out whether the assistance data includes information on usability of at least one of said two or more different satellite-positioning signals, wherein if the assistance data comprises information relating to the usability of at least one satellite-positioning signal, said examining element is further adapted to examine said information to find out an indication of the reference station to which said at least one satellite-positioning signal relates and the signal identity of said at least one satellite-positioning signal,

wherein the device is adapted not to use in the positioning such satellite-positioning signal which is indicated not to be usable.

2. A device according to claim 1, wherein said information relating to the usability is transmitted in a message comprising a Real-Time Integrity field, wherein said examining element is adapted to examine the Real-Time Integrity field to determine the number of satellite-positioning signals indicated not to be usable and the identity of satellite-positioning signals indicated not to be usable.

3. A device according to claim 2, wherein said Real-Time Integrity field comprises one Bad Signal Indication field for each non-usable satellite-positioning signal, wherein said examining element comprises a determining element adapted to examine the number of Bad Signal Indication fields in the Real-Time Integrity field to determine the number of satellite-positioning signals indicated not to be usable.

4. A device according to claim 3, wherein said Bad Signal Indication field comprises said indication on the reference station the non-usable satellite-positioning signal relates to.

5. A device according to claim 4, wherein said indication on the reference station the satellite-positioning signal relates to is assigned a predetermined value to indicate that all satellite-positioning signals of one reference station are not usable, wherein said Real-Time Integrity field comprises only one Bad Signal Indication field for such a reference station.

6. A device according to claim 3, wherein said determining element is adapted to determine that all satellite-positioning signals of the navigation system are usable when the examination indicates that there are none of the Bad Signal Indication fields in the Real-Time Integrity field.

7. A device according to claim 1, wherein the positioning receiver is adapted to receive satellite-positioning signals from at least two different navigation systems.

8. A device according to claim 1, wherein said information comprises an indication of the navigation system to which the assistance data relates, wherein the examining element is adapted to examine said indication of the navigation system.

9. A device according to claim 1, wherein the device is a mobile communication device.