Method and arrangement for improving the accuracy of positioning-related time measurements in radio system
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.
1. A 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;
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;
determining a 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,
wherein the method is used for improving the accuracy of time measurements related to positioning in a radio system.
2. The 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.
3. The method as claimed in claim 1 , wherein the receiver used in positioning is the receiver of a location measurement unit.
4. The method as claimed in claim 1 , wherein the receiver used in positioning is the receiver of the user equipment.
5. The method as claimed in claim 1 , comprising signaling the determined propagation delay to a controller of the radio system.
6. The method as claimed in claim 1 , comprising using the determined propagation delay in compensating delay.
7. The method as claimed in claim 1 , comprising using the determined propagation delay to adjust the delay of all receivers used in positioning to be the same.
8. The method as claimed in claim 1 , comprising using the determined propagation delay to calculate an absolute time.
9. The method as claimed in claim 1 , comprising using the transmission signal of a radio system transmitter in the receiver used in positioning as the test signal.
10. The method as claimed in claim 1 , comprising using the transmission signal of a radio system base transceiver station in the receiver used in positioning as the test signal.
11. The method as claimed in claim 1 , comprising using the common pilot channel of the radio system base transceiver station in the receiver used in positioning in determining the propagation delay.
12. The method as claimed in claim 11 , 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.
13. The method as claimed in claim 11 , comprising generating the common pilot channel signal of the transmitter in the receiver used in positioning and used as the test signal.
14. The method as claimed in claim 1 , comprising generating the test signal on different frequencies and determining the propagation delay on different frequencies.
15. The method as claimed in claim 1 , comprising using a separate test signal generated for the purpose as the test signal.
16. The method as claimed in claim 1 , comprising using a non-modulated sine wave as the test signal.
17. The method as claimed in claim 1 , comprising directing one finger of a RAKE receiver used in positioning to receive the test signal.
18. An arrangement, comprising:
a receiver to be used in positioning;
a generating unit configured to generate a test signal;
a directing unit configured to direct the test signal to pass through pre-selected radio frequency parts of the receiver used in positioning;
a unit configured to direct 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 to determine the propagation delay by means of a phase difference between the signals that traveled along the first and second routes;
a determining unit configured to determine the propagation delay of the test signal through the pre-selected radio frequency parts; and
a unit configured to use the determined propagation delay in improving the accuracy of the time measurements related to positioning,
wherein the arrangement is configured to improve 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.
19. The arrangement as claimed in claim 18 , comprising a storing unit configured to store 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.
20. The arrangement as claimed in claim 18 , wherein the receiver used in positioning is the receiver of a location measurement unit in the radio system.
21. The arrangement as claimed in claim 18 , wherein the receiver used in positioning is the receiver of the user equipment.
22. The arrangement as claimed in claim 18 , wherein the determined propagation delay is signaled to a controller in the radio system.
23. The arrangement as claimed in claim 18 , wherein the determined propagation delay is used in compensating delay.
24. The arrangement as claimed in claim 18 , wherein the determined propagation delay is used to adjust the delay of all receivers used in positioning to be the same.
25. The arrangement as claimed in claim 18 , wherein the determined propagation delay is used to calculate an absolute time.
26. The arrangement as claimed in claim 18 , wherein the transmission signal of a radio system base transceiver station in the receiver used in positioning is used as the test signal.
27. The arrangement as claimed in claim 18 , 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.
28. The arrangement as claimed in claim 27 , wherein the common pilot channel signal of the transmitter in the receiver used in positioning is generated and used as the test signal.
29. The arrangement as claimed in claim 27 , 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.
30. The arrangement as claimed in claim 18 , wherein the test signal can be generated on different frequencies and the propagation delay can be determined on different frequencies.
31. The arrangement as claimed in claim 18 , wherein a separate test signal generated for the purpose is used as the test signal.
32. The arrangement as claimed in claim 18 , wherein a non-modulated sine wave is used as the test signal.
33. The arrangement as claimed in claim 18 , wherein the arrangement comprises a RAKE receiver used in positioning and one finger of the RAKE receiver is directed to receive the test signal.
34. An apparatus, 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 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 to determine the propagation delay by means of a phase difference between the signals that traveled alone the first and second routes;
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,
wherein the arrangement is configured to improve 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.