Estimating signal strength measurements in a telecommunications system

• US 20050032520A1
• Filed: 02/04/2002
• Published: 02/10/2005
• Est. Priority Date: 02/16/2001
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Muller, Walter
• Granted Patent: US 7,171,211 B2
• Time in Patent Office: Days
• US Class Current: 455/448
• CPC Class Codes: H04B 17/327 Received signal code power [RSCP]
• CPC Class Codes: H04W 72/54 based on quality criteria

Abstract

The number of measurements being performed in a telecommunications system can be reduced by performing a predetermined measurement in Cell A and in co-located Cell B, step 1, for example a received signal code power (RSCP) measurement. The difference between the two signals is determined, and stored for future reference, step 3. Once the difference value has been established, the mobile station no longer needs to perform measurements on both Cell A and Cell B. Instead, if a subsequent measurement is made on Cell A, step 5, the network can estimate the measurement for Cell B based on the difference signal previously determined, step 7.

Claims

1. A method of estimating a signal measurement in a telecommunications system, the method comprising the steps of:

performing a first measurement in first and second co-located cells of the telecommunications system;

determining a difference value between the measurements; and

using the difference value to estimate a second measurement for the second cell, based on a second measurement being made in the first cell.

2. A method as claimed in claim 1, wherein the second measurement is the same type of measurement as the first measurement.

3. A method as claimed in claim 1, wherein the second measurement is a different type of measurement to the first measurement, but having a predetermined relationship to the first measurement.

4. A method as claimed in claim 3, wherein the second measurement is a CPICH Ec/No measurement.

5. A method as claimed in any one of claims 1 to 4, wherein the first measurement is a received signal code power (RSCP) measurement.

6. A method as claimed in any one of the preceding claims, wherein the measurements are performed at a mobile station in the telecommunications system and the difference value stored at a network side of the telecommunications system.

7. A method as claimed in any one of the preceding claims, wherein the method of estimating a measurement is used to evaluate which cells should belong to an active set on a frequency other than the frequency being used.

8. A method of handover in a cellular telecommunications system, the method of handover using a method of estimating a signal strength measurement as defined in any one of claims 1 to 7.

9. A telecommunications system in which signal strength measurements are performed in two or more co-located cells, the system comprising:

means for measuring a first measurement in first and second co-located cells of the telecommunications system;

means for determining a difference value between the measurements; and

means for estimating a second measurement for the second cell, based on a second measurement being made in the first cell and the previously determined difference value.

10. A system as claimed in claim 9, wherein the second measurement is the same type of measurement as the first measurement.

11. A system as claimed in claim 9, wherein the second measurement is a different type of measurement to the first measurement, but having a predetermined relationship to the first measurement.

12. A system as claimed in claim 11, wherein the second measurement is a CPICH Ec/No measurement.

13. A system as claimed in any one of claims 9 to 12, wherein the first measurement is a received signal code power (RSCP) measurement.

14. A system as claimed in any one of claims 9 to 13, wherein the measurements are performed at a mobile station in the telecommunications system and the difference value stored at a network side of the telecommunications system.

15. A system as claimed in any one of claims 9 to 14, having means for evaluating which cells should belong to an active set on a frequency other than the frequency being used.

30. A mobile communications terminal for use in a telecommunications system as described in any one of claims 9 to 15.

16. A method of estimating a signal measurement substantially as hereinbefore described, with reference to, and as shown in FIG. 1 or 2 of the accompanying drawings.

17. A telecommunications system substantially as hereinbefore described, with reference to, and as shown in FIG. 1 or 2 of the accompanying drawings.

18. A communications node for a telecommunications system in which signal strength measurements are performed in two or more co-located cells, the communications node comprising:

means for receiving a first measurement from first and second co-located cells of the telecommunications system;

means for determining a difference value between the measurements; and

means for estimating a second measurement for the second cell, based on a second measurement being made in the first cell and the previously determined difference value.

19. A communications node as claimed in claim 18, wherein the second measurement is the same type of measurement as the first measurement.

20. A communications node as claimed in claim 18, wherein the second measurement is a different type of measurement to the first measurement, but having a predetermined relationship to the first measurement.

21. A communications node as claimed in claim 20, wherein the second measurement is a CPICH Ec/No measurement.

22. A communications node as claimed in any one of claims 18 to 21, wherein the first measurement is a received signal code power (RSCP) measurement.

23. A communications node substantially as hereinbefore described, with reference to, and as shown in FIG. 1 or 2 of the accompanying drawings.

24. A method of estimating a signal measurement in a communications node of a telecommunications system, the method comprising the steps of:

receiving a first measurement from first and second co-located cells of the telecommunications system;

determining a difference value between the measurements; and

using the difference value to estimate a second measurement for the second cell, based on a second measurement being made in the first cell.

25. A method as claimed in claim 24, wherein the second measurement is the same type of measurement as the first measurement.

26. A method as claimed in claim 24, wherein the second measurement is a different type of measurement to the first measurement, but having a predetermined relationship to the first measurement.

27. A method as claimed in claim 26, wherein the second measurement is a CPICH Ec/No measurement.

28. A method as claimed in any one of claims 24 to 27, wherein the first measurement is a received signal code power (RSCP) measurement.

29. A method of estimating a signal measurement in a communications node of a telecommunications system, the method being substantially as hereinbefore described, with reference to, and as shown in FIG. 1 or 2 of the accompanying drawings.