Method of determining the position of a mobile unit

• US 20030212487A1
• Filed: 06/13/2003
• Published: 11/13/2003
• Est. Priority Date: 09/20/2000
• Status: Active Grant

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Marshall, Christopher B., Yule, Andrew T., Dooley, Saul R.
• Granted Patent: US 7,089,112 B2
• Time in Patent Office: Days
• US Class Current: 701/213
• CPC Class Codes: G01S 19/34 Power consumption
• CPC Class Codes: G01S 19/41 Differential correction, e.g. DGPS [differential GPS]
• CPC Class Codes: G01S 19/46 the supplementary measurement being of a radio-wave signal type
• CPC Class Codes: G01S 19/51 Relative positioning
• CPC Class Codes: G01S 2205/008 using a mobile telephone network
• CPC Class Codes: G01S 5/0027 of actual mobile position, i.e. position determined on mobile
• CPC Class Codes: G01S 5/0063 of measured values, i.e. measurement on base station and position calculation on mobile

Abstract

A method of determining the position of a mobile unit (MS1) having a GPS receiver (24) is disclosed. The method comprising the steps of measuring mobile unit pseudoranges at the mobile unit (MS1) using the GPS receiver (24); providing reference pseudoranges corresponding to a reference location situated remote from the mobile unit (BS1); and determining the position of the mobile unit (MS1) relative to the reference location (BS1) as a function of both the reference pseudoranges and the mobile unit pseudoranges.

Claims

1. A method of determining the position of a mobile unit having a GPS receiver comprising the steps of measuring mobile unit pseudoranges at the mobile unit using the GPS receiver;

providing reference pseudoranges corresponding to a reference location situated remote from the mobile unit; and

determining the position of the mobile unit relative to the reference location as a function of both the reference pseudoranges and the mobile unit pseudoranges.

2. A method according to claim 1 further comprising the step of determining the absolute position of the mobile unit from both the reference location and the relative position of the mobile unit to the reference location.

3. A method according to claim 1 or claim 2 wherein the position of the mobile unit relative to the reference location is determined as a function of the difference between the reference pseudoranges and the mobile unit pseudoranges.

4. A method according to any of the preceding claims further comprising the step of providing GPS satellite position information relative to the reference location wherein the position of the mobile unit relative to the reference location is determined as a function of the GPS satellite position information.

5. A method according to claim 4 wherein the GPS satellite position information is provided in the form of normalised direction vectors of the GPS satellites relative to the reference location.

6. A method according to claim 5 wherein the position of the mobile unit (X_m, Y_m, Z_m) relative to the reference location (X_ref, Y_ref, Z_ref) is determined using the following approximation:

7. A method according to any of claims 4 to 6 wherein the GPS satellite position information is obtained from GPS satellite signals received by a GPS receiver located at the reference location.

8. A method according to any of the preceding claims wherein the reference pseudoranges are provided by measuring pseudoranges using a GPS receiver located at the reference location.

9. A method according to any of claims 4 to 6 wherein the GPS satellite position information is provided by calculation based on the reference location and GPS satellite signal information obtained from GPS satellite signals received by a GPS receiver located remote from the reference location.

10. A method according to any of claims 1 to 6 wherein the reference pseudoranges are provided by calculation based on the reference location and GPS satellite signal information obtained from a GPS receiver located remote from the reference location.

11. A method according to any of the preceding claims wherein the mobile unit pseudoranges are transmitted from the mobile unit to a communications base station, and wherein the position of the mobile unit relative to the reference location is determined remote from the mobile unit.

12. A method according to any of claims 1 to 10 wherein the reference pseudoranges are transmitted from a communications base station to the mobile unit, and wherein the position of the mobile unit relative to the reference location is determined at the mobile unit.

13. A method according to claim 12 further comprising the step of transmitting the position of the mobile unit relative to the reference location from the mobile unit to the communications base station.

14. A method according to claim 12 further comprising the step of transmitting the reference location from the communications base station to the mobile unit.

15. A method according to claim 14 further comprising the step of transmitting the absolute position of the mobile unit from the mobile unit to the communications base station.

16. A method according to any of claims 12 to 15 wherein the reference location geographically coincides with the location of the communications base station.

22. A mobile unit comprising a GPS receiver and able to determine its position using a method according to any of claims 12 to 21.

17. A method of determining the position of a mobile unit having a GPS receiver comprising the steps of measuring pseudoranges at the mobile unit;

determining the position of the mobile unit relative to a nearby reference location using the pseudoranges; and

determining the absolute position of the mobile unit from both the reference location and the relative position of the mobile unit to the reference location.

18. A method of determining the position of a mobile unit having a GPS receiver comprising the steps of measuring mobile unit pseudoranges at the mobile unit using the GPS receiver;

receiving GPS ephemeris data in the form of Keplerian parameters at a reference location located remote from the mobile unit;

calculating from the ephemeris data satellite vector information in Cartesian form describing either or both of the position or movement of GPS satellites;

providing the satellite vector information to the mobile unit; and

determining the position of the mobile unit as a function of the satellite vector information and the mobile unit pseudoranges.

19. A method according to claim 18 wherein the satellite vector information comprises position (x,y,z) and velocity ({dot over (x)},{dot over (y)},{dot over (z)}) vectors describing the position and movement of the GPS satellites respectively.

20. A method according to claim 18 or claim 19 wherein the satellite vector information comprises acceleration ({umlaut over (x)},ÿ

,{umlaut over (z)}) vectors describing the movement of the GPS satellites.

21. A method according to any of claims 18 to 20 wherein the satellite vector information comprises 4^th or higher order vectors describing the movement of the GPS satellites.

23. A mobile unit comprising a communications receiver for receiving reference pseudoranges corresponding to a reference location situated remote from the mobile unit;

a GPS receiver for measuring mobile unit pseudoranges; and

a GPS processor for determining the position of the mobile unit relative to the reference location as a function of both the reference pseudoranges and the mobile unit pseudoranges.

24. A mobile unit according to claim 23 wherein the GPS receiver is further configured to determine the absolute position of the mobile unit from both reference location and the relative position of the mobile unit to the reference location.

25. A mobile unit comprising a GPS receiver for measuring pseudoranges at the mobile unit;

and a GPS processor for determining the position of the mobile unit relative to a nearby reference location using the pseudoranges, and determining the absolute position of the mobile unit from both the reference location and the relative position of the mobile unit to the reference location.

26. A mobile unit comprising a communications receiver for receiving satellite vector information in Cartesian form describing either or both of the position or movement of GPS satellites;

a GPS receiver for measuring mobile unit pseudoranges from GPS satellite signals modulated by GPS ephemeris data in the form of Keplerian parameters; and

a GPS processor for determining the position of the mobile unit as a function of both the satellite vector information and the mobile unit pseudoranges.

27. A mobile unit according to claim 26 wherein the satellite vector information comprises position (x,y,z) and velocity ({dot over (x)},{dot over (y)},{dot over (z)}) vectors describing the position and movement of the GPS satellites respectively.

28. A mobile unit according to claim 26 or claim 27 wherein the satellite vector information comprises acceleration ({umlaut over (x)},ÿ

,{umlaut over (z)}) vectors describing the movement of the GPS satellites.

29. A mobile unit according to any of claims 26 to 28 wherein the satellite vector information comprises 4^th or higher order vectors describing the movement of the GPS satellites.

30. Positioning apparatus comprising a GPS receiver for measuring GPS pseudoranges;

and a transmitter for transmitting the pseudoranges to another GPS receiver located remote from the positioning apparatus.

31. Positioning apparatus according to claim 30 further adapted to transmit the its position to the other GPS receiver.

32. Positioning apparatus according to claim 31 wherein the position of the positioning apparatus provided to the other GPS receiver is not determined using the pseudorange measurements provided to that GPS receiver.

33. Positioning apparatus according to claim 32 wherein the position of the positioning apparatus provided to the other GPS receiver is not determined using the GPS receiver of positioning apparatus.

34. Positioning apparatus comprising a GPS receiver for receiving GPS ephemeris data in the form of Keplerian parameters;

a processor for calculating from the ephemeris data satellite vector information in Cartesian form describing either or both of the position or movement of GPS satellites; and

a transmitter for transmitting the satellite vector information to another GPS receiver located remote from the positioning apparatus.

35. Positioning apparatus according to claim 34 wherein the satellite vector information comprises position (x,y,z) and velocity ({dot over (x)},{dot over (y)},{dot over (z)}) vectors describing the position and movement of the GPS satellites respectively.

36. Positioning apparatus according to claim 34 or claim 35 wherein the satellite vector information comprises acceleration ({umlaut over (x)},ÿ

,{umlaut over (z)}) vectors describing the movement of the GPS satellites.

37. Positioning apparatus according to any of claims 34 to 36 wherein the satellite vector information comprises 4^th or higher order vectors describing the movement of the GPS satellites.