Method and arrangement for improving the accuracy of positioning-related time measurements in radio system

• US 20040073392A1
• Filed: 07/01/2003
• Published: 04/15/2004
• Est. Priority Date: 07/01/2002
• Status: Active Grant

• Current Assignee: Nokia Corporation
• Original Assignee: Nokia Corporation
• Inventors: Immonen, Ari, Toljamo, Petri
• Granted Patent: US 7,187,905 B2
• Time in Patent Office: Days
• US Class Current: 702/89
• CPC Class Codes: G01S 5/021 Calibration, monitoring or correction G01S5/0252 takes precedence

Abstract

The invention relates to a method and arrangement for improving the accuracy of time measurements related to positioning in a radio system. In the method, a test signal is generated; the test signal is directed to travel through pre-selected radio frequency parts of a receiver used in positioning in the radio system; the propagation delay of the test signal through the pre-selected radio frequency parts is determined; and the determined propagation delay is used to improve the accuracy of time measurement related to positioning.

Claims

1. A method for improving the accuracy of time measurements related to positioning in a radio system,

the method comprising:

generating a test signal,

directing the test signal to pass through pre-selected radio frequency parts of a receiver used by the radio system in positioning,

determining the propagation delay of the test signal through the pre-selected radio frequency parts, and

using the determined propagation delay in improving the accuracy of the time measurements related to positioning.

2. A method as claimed in claim 1, comprising directing the test signal to travel along two routes, of which the first route goes through the pre-selected radio frequency parts, and the second route past them, and determining the propagation delay by means of a phase difference between the signals that traveled along the first and second routes.

3. A method as claimed in claim 1, comprising storing the time instants, when the test signal starts and ends its travel through the pre-selected radio frequency parts, and determining the propagation delay by using the stored time instants.

4. A method as claimed in claim 1, wherein the receiver used in positioning is the receiver of a location measurement unit.

5. A method as claimed in claim 1, wherein the receiver used in positioning is the receiver of the user equipment.

6. A method as claimed in claim 1, wherein the determined propagation delay is signaled to a controller of the radio system.

7. A method as claimed in claim 1, wherein the determined propagation delay is used in compensating delay.

8. A method as claimed in claim 1, wherein the determined propagation delay is used to adjust the delay of all receivers used in positioning to be the same.

9. A method as claimed in claim 1, wherein the determined propagation delay is used to calculate an absolute time.

10. A method as claimed in claim 1, wherein the transmission signal of a radio system transmitter in the receiver used in positioning is used as the test signal.

11. A method as claimed in claim 1, wherein the transmission signal of a radio system base transceiver station in the receiver used in positioning is used as the test signal.

12. A method as claimed in claim 1, wherein the common pilot channel of the radio system base transceiver station in the receiver used in positioning is used in determining the propagation delay.

13. A method as claimed in claim 12, wherein the test signal is the common pilot channel signal with the pilot channel code sequence of the transmitter in the receiver used in positioning added to its radio frame during its idle period.

14. A method as claimed in claim 12, wherein the common pilot channel signal of the transmitter in the receiver used in positioning is generated and used as the test signal.

15. A method as claimed in claim 1, wherein the test signal can be generated on different frequencies and the propagation delay can be determined on different frequencies.

16. A method as claimed in claim 1, wherein a separate test signal generated for the purpose is used as the test signal.

17. A method as claimed in claim 1, wherein a non-modulated sine wave is used as the test signal.

18. A method as claimed in claim 1, wherein one finger of a RAKE receiver used in positioning is directed to receive the test signal.

19. An arrangement for improving the accuracy of time measurements related to positioning in a radio system, comprising at least one user equipment to be positioned, and at least three base transceiver stations having known locations and used in positioning, of which base transceiver stations one acts as a serving base transceiver station to the user equipment,

the arrangement further comprising:

a receiver to be used in positioning,

means for generating a test signal,

means for directing the test signal to pass through pre-selected radio frequency parts of the receiver used in positioning,

means for determining the propagation delay of the test signal through the pre-selected radio frequency parts, and

means for using the determined propagation delay in improving the accuracy of the time measurements related to positioning.

20. An arrangement as claimed in claim 19, comprising directing the test signal to travel along two routes, of which the first route goes through the pre-selected radio frequency parts, and the second route past them, and determining the propagation delay by means of a phase difference between the signals that traveled along the first and second routes.

21. An arrangement as claimed in claim 19, comprising means for storing the time instants, when the test signal starts and ends its travel through the pre-selected radio frequency part, and determining the propagation delay by using the stored time instants.

22. An arrangement as claimed in claim 19, wherein the receiver used in positioning is the receiver of a location measurement unit in the radio system.

23. An arrangement as claimed in claim 19, wherein the receiver used in positioning is the receiver of the user equipment.

24. An arrangement as claimed in claim 19, wherein the determined propagation delay is signaled to a controller in the radio system.

25. An arrangement as claimed in claim 19, wherein the determined propagation delay is used in compensating delay.

26. An arrangement as claimed in claim 19, wherein the determined propagation delay is used to adjust the delay of all receivers used in positioning to be the same.

27. An arrangement as claimed in claim 19, wherein the determined propagation delay is used to calculate an absolute time.

28. An arrangement as claimed in claim 19, wherein the transmission signal of a radio system base transceiver station in the receiver used in positioning is used as the test signal.

29. An arrangement as claimed in claim 19, wherein the common pilot channel of the radio system base transceiver station in the receiver used in positioning is used in determining the propagation delay.

30. An arrangement as claimed in claim 29, wherein the test signal is the common pilot channel signal with the pilot channel code sequence of the transmitter in the receiver used in positioning added to its radio frame during its idle period.

31. An arrangement as claimed in claim 29, wherein the common pilot channel signal of the transmitter in the receiver used in positioning is generated and used as the test signal.

32. An arrangement as claimed in claim 19, wherein the test signal can be generated on different frequencies and the propagation delay can be determined on different frequencies.

33. An arrangement as claimed in claim 19, wherein a separate test signal generated for the purpose is used as the test signal.

34. An arrangement as claimed in claim 19, wherein a nonmodulated sine wave is used as the test signal.

35. An arrangement as claimed in claim 19, wherein the arrangement comprises a RAKE receiver used in positioning and one finger of the RAKE receiver is directed to receive the test signal.