Method, system and devices for positioning a receiver

• US 6,771,211 B2
• Filed: 11/13/2001
• Issued: 08/03/2004
• Est. Priority Date: 11/13/2001
• Status: Expired due to Term

• Current Assignee: RPX Corporation
• Original Assignee: Nokia Corporation
• Inventors: Kontola, Ilkka, Valio, Harri, Syrjarinne, Jari
• Primary Examiner(s): Blum, Theodore M.
• Application Number:
  US10/012,061
• Publication Number:
  US 20030090413A1
• Time in Patent Office: 994 Days
• Field of Search: 342/357.05, 342/357.15
• US Class Current: 342/357.65
• CPC Class Codes: G01S 19/13 Receivers
• CPC Class Codes: G01S 19/256 relating to timing, e.g. time of week, code phase, timing offset
• CPC Class Codes: G01S 19/258 relating to the satellite constellation, e.g. almanac, ephemeris data, lists of satellites in view
• CPC Class Codes: G01S 19/42 Determining position

Abstract

The invention relates to a method for positioning a receiver receiving code modulated signals transmitted by satellites and formed by an individual code for each satellite. In order to provide a reliable reference position for the receiver, it is proposed that in a first step, a reference position for said receiver is calculated based on frequency measurements of said code modulated signals. This reference position can then be employed in a second step for determining the accurate position of the receiver. The invention equally relates to such a receiver, to positioning means, to a computing server and to a positioning system comprising means for realizing the proposed method.

Claims

1. A method for positioning a receiver receiving code modulated signals transmitted by satellites and formed by an individual code for each satellite, wherein in a first step, a reference position for said receiver is calculated based on at least three frequency measurements of said code modulated signals, which reference position is employed in a second step for determining an accurate position of said receiver,

wherein at least three measurements enabling the calculation of pseudoranges are used in said second step.

2. The method according to claim 1, wherein said frequency measurements are Doppler frequency measurements.

3. The method according to claim 1, wherein said calculated reference position is employed in a time recovery method, which time recovery method provides assistance information for determining said accurate position of said receiver.

4. The method according to claim 1, wherein for calculating said reference position based on frequency measurements, the velocity of said receiver is assumed to be zero.

5. The method according to claim 1, wherein said reference position is determined in case there are signals from 4 to 6 satellites available at said receiver.

6. The method according to claim 1, wherein said satellites are GPS satellites and wherein said receiver is a GPS receiver.

7. Positioning means for positioning a receiver based on code modulated signals transmitted by satellites and formed by an individual code for each satellite, wherein results of frequency measurements on said code modulated signals are provided to said positioning means by receiving means of said receiver, and wherein said positioning means comprises:

means for calculating a reference position for said receiver based on said results of at least three of said frequency measurements; and

means for determining an exact position of said receiver based on said calculated reference position using at least three measurements enabling the calculation of pseudoranges.

8. The positioning means according to claim 7, wherein said positioning means are integrated in a GPS receiver.

9. The positioning means according to claim 7, wherein said positioning means are integrated in a computing server to which at least one GPS receiver has access.

10. Receiver comprising receiving means for receiving code modulated signals transmitted by satellites and formed by an individual code for each satellite, and comprising positioning means with:

means for carrying out at least three frequency measurements on the received code modulated signals;

means for calculating a reference position for said receiver based on said frequency measurements; and

means for determining an exact position of said receiver based on said calculated reference position using at least three measurements enabling the calculation of pseudoranges.

11. The receiver according to claim 10, wherein said receiver is a GPS receiver.

12. Computing server for positioning a receiver, comprising at least means for receiving via said receiver results of frequency measurements on code modulated signals transmitted by satellites and formed by an individual code for each satellite, and positioning means with:

means for calculating a reference position for said receiver based on at least three of said frequency measurements; and

means for determining an exact position of said receiver based on said calculated reference position using at least three measurements enabling the calculation of pseudoranges.

13. The computing server according to claim 12, wherein said computing server provides access for at least one GPS receiver.

14. Positioning system comprising at least one receiver with receiving means for receiving code modulated signals transmitted by satellites and formed by an individual code for each satellite and with means for performing frequency measurements on said received code modulated signals, and further comprising at least one computing server with positioning means including:

means for calculating a reference position for said receiver based on at least three of said frequency measurements; and

means for determining an exact position of said receiver based on said calculated reference position using at least three measurements enabling the calculation of pseudoranges.

15. The positioning system according to claim 14, wherein said at least one receiver is a GPS receiver receiving signals from GPS satellites.