Method and system for measuring and reporting received signal strength

• US 6,728,228 B1
• Filed: 12/30/1999
• Issued: 04/27/2004
• Est. Priority Date: 09/20/1999
• Status: Expired due to Fees

• Current Assignee: Unwired Planet LLC (JP Morgan Chase & Co)
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Östman, Thomas, Forde, Andrew, Hagerman, Bo
• Primary Examiner(s): HO, DUC CHI
• Application Number:
  US09/475,640
• Time in Patent Office: 1,580 Days
• Field of Search: 370/321, 370/331, 370/332, 370/333, 370/336, 370/347, 370/337, 370/431, 455/522, 455/507, 455/517, 455/509, 455/562, 455/63, 455/69, 455/127, 455/13.4, 455/226.1, 455/226.2, 455/437
• US Class Current: 370/332
• CPC Class Codes: H04B 17/24 with feedback of measurements to the transmitter
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04W 52/32 TPC of broadcast or control channels
• CPC Class Codes: H04W 52/54 Signalisation aspects of the TPC commands, e.g. frame structure

Abstract

In a Time Division Multiple Access based radio telecommunications system that employs downlink power control, received signal strength information is measured and reported. A downlink data signal is transmitted from a base station to a mobile station during a first timeslot. A control channel signal or a dedicated traffic channel signal having equivalent output power behavior as the control channel, is transmitted from the base station throughout a cell in which the mobile station is operating. At the mobile station, a received signal strength of the control channel signal or the dedicated traffic channel signal is measured. The received signal strength may be measured in period between when the mobile station transmits and receives or in a period between when the mobile station received and transmits. The received signal strength may be measured during the first timeslot or during a timeslot other than said first timeslot. The received signal strength may also be measured during a time period associated with Mobile Assisted Handover (MAHO) measurements, the MAHO list including the control channel and/or the dedicated traffic channel. The received signal strength as measured by the mobile station is reported to the base station. The measured received signal strength is compensated for to obtain signal strength information associated with the downlink data signal received by the mobile station during the first timeslot.

Claims

1. In a Time Division Multiple Access based radio telecommunications system that employs downlink power control, a method of measuring and reporting received signal strength information, said method comprising the steps of:

transmitting a downlink data signal from a base station to a mobile station during a first timeslot, said data signal being transmitted at a power level that is variable due to downlink power control;

transmitting a control channel signal from the base station throughout a cell in which the mobile station is operating, said control channel signal being transmitted at a power level that is constant;

at the mobile station, measuring a received signal strength of the control channel signal;

reporting the received signal strength of the control channel signal, as measured by the mobile station, to the base station; and

compensating for the measured received signal strength of the control channel signal to derive signal strength information associated with the downlink data signal received by the mobile station during the first timeslot.

2. The method of claim 1, wherein the downlink data signal is attenuated before being transmitted, and said step of compensating comprises subtracting the attenuation level associated with the downlink data signal from the received signal strength measurement associated with the control channel signal.

3. The method of claim 1, wherein said step of compensating comprises adding a difference between an output power level of the downlink data signal and an output power level of the control channel signal to the received signal strength measurement associated with the control channel signal.

4. The method of claim 1, wherein different antenna systems are used for transmitting the control channel signal and the downlink data signal, and the step of compensating compensates for the different antenna system gains.

5. The method of claim 1, wherein different frequency bands are used for transmitting the control channel signal and the downlink data signal, and the step of compensating compensates for different propagations at different frequencies.

6. The method of claim 1, wherein said step of measuring the received signal strength of the control channel comprises the step of:

measuring the received signal strength in a period between when the mobile station transmits and when the mobile station receives.

7. The method of claim 1, wherein said step of measuring the received signal strength of the control channel comprises the step of:

measuring the received signal strength in a period between when the mobile station receives and when the mobile station transmits.

8. The method of claim 1, wherein said step of measuring the received signal strength of the control channel signal comprises the step of:

measuring the received signal strength during the first timeslot.

9. The method of claim 1, wherein said step of measuring the received signal strength of the control channel signal comprises the step of:

measuring the received signal strength during a timeslot other than said first timeslot.

10. The method of claim 1, wherein said step of measuring the received signal strength of the control channel signal comprises the step of:

measuring the received signal strength during a time period associated with Mobile Assisted Handover (MAHO) measurements.

11. The method of claim 10, wherein MAHO measurements are performed for control channels contained in a MAHO list that includes the base station'"'"'s control channel.

12. The method of claim 1, wherein the step of measuring measures the received signal strength in a dedicated traffic channel having an equivalent output power behavior as the control channel.

13. The method of claim 12, wherein the downlink data signal is attenuated before being transmitted, and said step of compensating comprises subtracting the attenuation level associated with the downlink data signal from the received signal strength measurement associated with the dedicated traffic channel signal.

14. The method of claim 12, wherein said step of compensating comprises adding a difference between an output power level of the downlink data signal and an output power level of the dedicated traffic channel signal to the received signal strength measurement associated with the dedicated traffic channel signal.

15. The method of claim 12, wherein different antenna systems are used for transmitting the dedicated traffic channel signal and the downlink data signal, and the step of compensating compensates for the different antenna system gains.

16. The method of claim 12, wherein different frequency bands are used for transmitting the dedicated traffic channel signal and the downlink data signal, and the step of compensating compensates for different propagations at different frequencies.

17. The method of claim 12, wherein said step of measuring the received signal strength of the dedicated traffic channel signal comprises the step of:

measuring the received signal strength in a period between when the mobile station transmits and when the mobile station receives.

18. The method of claim 12, wherein said step of measuring the received signal strength of the dedicated traffic channel signal comprises the step of:

measuring the received signal strength in a period between when the mobile station receives and when the mobile station transmits.

19. The method of claim 12, wherein said step of measuring the received signal strength of the dedicated traffic channel signal comprises the step of:

measuring the received signal strength during the first timeslot.

20. The method of claim 12, wherein said step of measuring the received signal strength of the dedicated traffic channel signal comprises the step of:

measuring the received signal strength during a timeslot other than said first timeslot.

21. The method of claim 12, wherein said step of measuring the received signal strength of the dedicated traffic channel signal comprises the step of:

measuring the received signal strength during a time period associated with Mobile Assisted Handover (MAHO) measurements.

22. The method of claim 21, wherein MAHO measurements are performed for channels contained in a MAHO list that includes the a dedicated traffic channel.

23. In a Time Division Multiple Access based radio telecommunications system that employs downlink power control, a system for measuring and reporting received signal strength information, comprising:

means for transmitting a downlink data signal from a base station to a mobile station during a first timeslot at a power level that is variable due to downlink power control;

means for transmitting a control channel signal from the base station throughout a cell in which the mobile station is operating, said control channel signal being transmitted at a power level that is constant;

at the mobile station, means for measuring a received signal strength of the control channel signal;

means for reporting the received signal strength of the control channel signal, as measured by the mobile station, to the base station; and

means for compensating for the received signal strength of the control channel signal to obtain signal strength information associated with the downlink data signal received by the mobile station during the first timeslot.

24. The system of claim 23, wherein the downlink data signal is attenuated before being transmitted, and the compensating means comprises:

means for subtracting the attenuation level associated with the downlink data signal from the received signal strength measurement associated with the control channel signal.

25. The system of claim 23, wherein the compensating means adds a difference between an output power level of the downlink data signal and an output power level of the control channel signal to the received signal strength measurement associated with the control channel signal.

26. The system of claim 23, wherein different antenna systems are used for transmitting the control channel signal and the downlink data signal, and the compensating means compensates for the different antenna system gains.

27. The system of claim 23, wherein different frequency bands are used for transmitting the control channel signal and the downlink data signal, and the compensating means compensates for different propagations at different frequencies.

28. The system of claim 23, wherein the means for measuring the received signal strength of the control channel signal comprises:

means for measuring the received signal strength in a period between when the mobile station transmits and when the mobile station receives.

29. The system of claim 23, wherein the means for measuring the received signal strength of the control channel signal comprises:

means for measuring the received signal strength in a period between when the mobile station receives and when the mobile station transmits.

30. The system of claim 23, wherein the means for measuring the received signal strength of the control channel signal comprises:

means for measuring the received signal strength during the first timeslot.

31. The system of claim 23, wherein the means for measuring the received signal strength of the control channel signal comprises:

means for measuring the received signal strength during a timeslot other than said first timeslot.

32. The system of claim 23, wherein the means for measuring the received signal strength of the control channel signal comprises:

means for measuring the received signal strength during a time period associated with Mobile Assisted Handover (MAHO) measurements.

33. The system of claim 32, wherein MAHO measurements are performed for control channels contained in a MAHO list that includes the base station'"'"'s control channel.

34. The system of claim 23, wherein the measuring means measures the received signal strength in a dedicated traffic channel having an equivalent output power behavior as the control channel.

35. The system of claim 34, wherein the downlink data signal is attenuated before being transmitted, and the compensating means comprises:

means for subtracting the attenuation level associated with the downlink data signal from the received signal strength measurement associated with the dedicated traffic channel signal.

36. The system of claim 34, wherein the compensating means adds a difference between an output power level of the downlink date signal and an output power level of the control channel signal to the received signal strength measurement associated with the dedicated traffic channel signal.

37. The system of claim 34, wherein different antenna systems are used for transmitting the dedicated traffic channel signal and the downlink data signal, and the compensating means compensates for the different antenna system gains.

38. The system of claim 34, wherein different frequency bands are used for transmitting the dedicated traffic channel signal and the downlink data signal, and the compensating means compensates for different propagations at different frequencies.

39. The system of claim 34, wherein the means for measuring the received signal strength of the dedicated traffic channel signal comprises:

means for measuring the received signal strength in a period between when the mobile station transmits and when the mobile station receives.

40. The system of claim 34, wherein the means for measuring the received signal strength of the dedicated traffic channel signal comprises:

means for measuring the received signal strength in a period between when the mobile station receives and when the mobile station transmits.

41. The system of claim 34, wherein the means for measuring the received signal strength of the dedicated traffic channel signal comprises:

means for measuring the received signal strength during the first timeslot.

42. The system of claim 34, wherein the means for measuring the received signal strength of the dedicated traffic channel signal comprises:

means for measuring the received signal strength during a timeslot other than said first timeslot.

43. The system of claim 34, wherein the means for measuring the received signal strength of the dedicated traffic channel signal comprises:

means for measuring the received signal strength during a time period associated with Mobile Assisted Handoff (MAHO) measurements.

44. The system of claim 43, wherein MAHO measurements are performed for channels contained in a MAHO list that includes the dedicated traffic channel.