Method for positioning of an electronic device, a system, and an electronic device

• US 20040012523A1
• Filed: 05/15/2003
• Published: 01/22/2004
• Est. Priority Date: 05/16/2002
• Status: Active Grant

• Current Assignee: RPX Corporation
• Original Assignee: Nokia Corporation
• Inventors: Valio, Harri, Pietila, Samuli
• Granted Patent: US 6,882,306 B2
• Time in Patent Office: Days
• US Class Current: 342/357.15
• CPC Class Codes: G01S 19/243 Demodulation of navigation message
• CPC Class Codes: G01S 19/252 Employing an initial estimate of location in generating assistance data
• CPC Class Codes: G01S 19/28 Satellite selection

Abstract

The position of an electronic device (1) is determined by means of satellites in a positioning system by determining satellite orbit data and a default position for the electronic device (1). At least the following steps are taken: a determination step for determining a first time data estimate by using said default position, a computing step for computing an estimate of the code phase of the satellite signal on the basis of said time data estimate, the default position and the satellite orbit data, and a searching step, in which a code-modulated signal transmitted by satellites of a positioning system is received for searching the signal of at least one satellite and for acquiring the signal by using said estimate of the code phase. The invention also relates to a system, in which the method is applied, as well as to an electronic device (1).

Claims

1. A method for determining the position of an electronic device by means of satellites in a positioning system, where satellite orbit data is determined and a default position is determined for the electronic device, wherein the method comprises at least:

a determination step for determining a first time data estimate by using said default position,

a computing step for computing an estimate of the code phase of the satellite signal on the basis of said time data estimate, the default position and the satellite orbit data, and

a searching step, in which a code-modulated signal transmitted by satellites of a positioning system is received for searching the signal of at least one satellite and for acquiring the signal by using said estimate of the code phase.

2. The method according to claim 1, comprising changing said time data estimate, if acquisition of the signal from at least one other satellite cannot be performed on the basis of said first time data estimate, wherein said computing step and searching step are iterated, and that during each iteration, an altered time data estimate is used in said computing step.

3. The method according to claim 1, wherein the electronic device is used to receive information from a communication network, wherein the data about said default position is received from the communication network.

4. The method according to claim 3, wherein said communication network used is a mobile communication network with base stations for communication between the communication network and the electronic device, and that said default position used is the position of the base station through which the communication between the mobile communication network and the electronic device is carried out.

5. The method according to claim 3, wherein said communication network used is a mobile communication network, in which the position of the electronic device is determined, and that said default position used is the position of the electronic device determined in the communication network.

6. The method according to claim 1, comprising receiving the signal of one satellite for determining said first time data estimate, and performing acquisition of this signal to be received.

7. The method according to claim 1, comprising transmitting said first time data estimate from the communication network to the electronic device.

8. A system with means for determining the position of an electronic device by means of code-modulated signals transmitted by satellites in a positioning system, in which positioning system satellite orbit data are determined, and which system comprises means for determining a default position for the electronic device, the electronic device comprising means for receiving code-modulated signals transmitted by satellites in the positioning system, wherein the system comprises:

means for determining a first time data estimate by using said default position,

means for computing an estimate of the code phase of the satellite signal on the basis of said time data estimate, the default position and the satellite orbit data, and means for searching the signal of at least one satellite and for acquiring the signal by using said estimate of the code phase.

9. The system according to claim 8, comprising means for changing said time data estimate, if acquisition of at least one other satellite signal has not been possible on the basis of said first time data estimate, means for computing an estimate of the code phase of the satellite signal and for iterating the searching of the satellite signal, and means for using a changed time data estimate for each iteration.

10. The system according to claim 8, in which the electronic device is used to receive information from a communication network, wherein the electronic device comprises means for receiving data about said default position from the communication network.

11. The system according to claim 10, wherein said communication network is a mobile communication network with base stations for communication between the mobile communication network and the electronic device, and that said default position used is arranged to be the position of the base station through which the communication between the mobile communication network and the electronic device is arranged to be carried out.

12. The system according to claim 10, wherein said communication network is a mobile communication network with means for determining the position of the electronic device, and that said default position used is arranged to be the position of the electronic device determined in the mobile communication network.

13. The system according to claim 8, wherein the means for determining said first time data estimate comprise means for receiving the signal of one satellite and means for acquisition of the received signal.

14. The system according to claim 8, comprising means for transmitting said first time data estimate from the communication network to the electronic device.

15. An electronic device comprising means for determining the position by means of code-modulated signals transmitted by satellites in a positioning system, in which positioning system satellite orbit data are determined, and which electronic device comprises means for determining a default position for the electronic device, and means for receiving code-modulated signals transmitted by satellites in the positioning system, wherein the electronic device comprises:

means for determining a first time data estimate by using said default position,

means for computing an estimate of the code phase of the satellite signal on the basis of said time data estimate, the default position and the satellite orbit data, and

means for searching the signal of at least one satellite and for acquiring the signal by using said estimate of the code phase.

16. The electronic device according to claim 15, comprising means for changing said time data estimate, if acquisition of at least one other satellite signal has not been possible on the basis of said first time data estimate, means for computing an estimate of the code phase of the satellite signal and for iterating the searching of the satellite signal, and means for using a changed time data estimate for each iteration.

17. The electronic device according to claim 15, comprising means for storing orbit data of said satellites.

18. The electronic device according to claim 15, comprising means for performing mobile station functions.