Method and system for controlling power in a communication system

• US 20080159196A1
• Filed: 12/27/2007
• Published: 07/03/2008
• Est. Priority Date: 12/28/2006
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Tae-Young, Park, Jeong-Ho, Cho, Jae-Hee, Roh, Kwan-Hee, Koo, Jin-Kyu
• Granted Patent: US 8,300,572 B2
• Time in Patent Office: Days
• US Class Current: 370/311
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/245 taking into account received signal strength

Abstract

A method and system for controlling power in a communication system are provided, in which a base station calculates a power control value for an mobile station based on feedback information received from the mobile station, transmits power control information including the power control value to the mobile station, measures the strength of a signal received corresponding to the transmit power control information from the mobile station, determines the status of the mobile station using the signal strength and the power control value, and schedules the mobile station according to the determination.

Claims

1. A method for controlling power in a base station in a communication system, comprising:

calculating a power control value for a mobile station based on feedback information received from the mobile station;

transmitting power control information including the power control value to the mobile station;

measuring the strength of a signal received corresponding to the transmit power control information from the mobile station;

determining a status of the mobile station using the signal strength and the power control value; and

scheduling the mobile station according to the determination.

2. The method of claim 1, wherein the measurement comprises:

measuring a strength of a first signal received in a previous frame from the mobile station;

measuring a strength of a second signal received in a current frame from the mobile station; and

calculating a signal strength variation by calculating a difference between the first signal strength and the second signal strength.

3. The method of claim 2, wherein the signal strengths are measuring the signal-to-interference and noise ratios of the received signals from the mobile station.

4. The method of claim 2, wherein the status determination comprises:

calculating a racing metric value using the signal strength variation and the power control value; and

determining the status of the mobile station by comparing the racing metric value with a racing threshold.

5. The method of claim 4, wherein the status determination comprises:

accumulating calculated racing metric values repeatedly for a predetermined number of frames; and

determining the status of the mobile station by comparing the accumulated racing metric value with the racing threshold.

6. The method of claim 1, wherein the status determination comprises determining whether the mobile station is in an uplink power race.

7. The method of claim 6, wherein the scheduling comprises, if the mobile station is in an uplink power race, scheduling the mobile station in an uplink power race-avoiding manner so that the mobile station does not race in uplink power with a second mobile station within a cell neighboring to a cell covered by the base station.

8. The method of claim 7, wherein the scheduling of the mobile station in an uplink power race-avoiding manner comprises scheduling the mobile station so that the mobile station and the second mobile station within the neighbor cell transmit signals in different frequency bands.

9. The method of claim 7, wherein the scheduling of the mobile station in an uplink power race-avoiding manner comprises scheduling the mobile station so that the mobile station and the second mobile station within the neighbor cell transmit signals at different time points.

10. The method of claim 7, wherein the scheduling of the mobile station in an uplink power race-avoiding manner comprises scheduling the mobile station so as to reduce the number of subchannels allocated the mobile station and the second mobile station within the neighbor cell.

11. The method of claim 7, wherein the scheduling of the mobile station in an uplink power race-avoiding manner comprises scheduling the mobile station by changing modulation and coding scheme (MCS) levels of the mobile station and the second mobile station within the neighbor cell.

12. The method of claim 5, wherein the status determination comprises determining whether the mobile station is in an uplink power race.

13. The method of claim 12, wherein the scheduling comprises, if the mobile station is in an uplink power race, scheduling the mobile station in an uplink power race-avoiding manner so that the mobile station does not race in uplink power with a second mobile station within a cell neighboring to a cell covered by the base station.

14. The method of claim 13, wherein the scheduling of the mobile station in an uplink power race-avoiding manner comprises scheduling the mobile station so that the mobile station and the second mobile station within the neighbor cell transmit signals in different frequency bands.

15. The method of claim 13, wherein the scheduling of the mobile station in an uplink power race-avoiding manner comprises scheduling the mobile station so that the mobile station and the second mobile station within the neighbor cell transmit signals at different time points.

16. The method of claim 13, wherein the scheduling of the mobile station in an uplink power race-avoiding manner comprises scheduling the mobile station so as to reduce the number of subchannels allocated the mobile station and the second mobile station within the neighbor cell.

17. The method of claim 13, wherein the scheduling of the mobile station in an uplink power race-avoiding manner comprises scheduling the mobile station by changing modulation and coding scheme (MCS) levels of the mobile station and the second mobile station within the neighbor cell.

18. A system for controlling power in a communication system, comprising:

a base station for calculating a power control value for a mobile station based on feedback information received from the mobile station, transmitting power control information including the power control value to the mobile station, measuring the strength of a signal received corresponding to the transmit power control information from the mobile station, determining the status of the mobile station using the signal strength and the power control value, and scheduling the mobile station according to the determination.

19. The system of claim 18, wherein the base station measures a strength of a first signal received in a previous frame from the mobile station, measures a strength of a second signal received in a current frame from the mobile station, and calculates a signal strength variation by calculating a difference between the first signal strength and the second signal strength.

20. The system of claim 19, wherein the signal strengths are measuring the Signal-to-Interference and Noise Ratios (SINRs) of the received signals from the mobile station.

21. The system of claim 19, wherein the base station calculates a racing metric value using the signal strength variation and the power control value, and determines the status of the mobile station by comparing the racing metric value with a racing threshold.

22. The system of claim 21, wherein the base station accumulates calculated racing metric values repeatedly for a predetermined number of frames, and determines the status of the mobile station by comparing the accumulated racing metric value with the racing threshold.

23. The system of claim 18, wherein the base station determines whether the mobile station is in an uplink power race.

24. The system of claim 23, wherein if the mobile station is in an uplink power race, the base station schedules the mobile station in an uplink power race-avoiding manner so that the mobile station does not race in uplink power with a second mobile station within a cell neighboring to a cell covered by the base station.

25. The system of claim 24, wherein the base station schedules the mobile station so that the mobile station and the second mobile station within the neighbor cell transmit signals in different frequency bands.

26. The system of claim 24, wherein the base station schedules the mobile station so that the mobile station and the second mobile station within the neighbor cell transmit signals at different time points.

27. The system of claim 24, wherein the base station schedules the mobile station so as to reduce the number of subchannels allocated the mobile station and the second mobile station within the neighbor cell.

28. The system of claim 24, wherein the base station schedules the mobile station by changing modulation and coding scheme (MCS) levels of the mobile station and the second mobile station within the neighbor cell.

29. The system of claim 22, wherein the base station determines whether the mobile station is in an uplink power race.

30. The system of claim 29, wherein if the mobile station is in an uplink power race, the base station schedules the mobile station in an uplink power race-avoiding manner so that the mobile station does not race in uplink power with a second mobile station within a cell neighboring to a cell covered by the base station.

31. The system of claim 30, wherein the base station schedules the mobile station so that the mobile station and the second mobile station within the neighbor cell transmit signals in different frequency bands.

32. The system of claim 30, wherein the base station schedules the mobile station so that the mobile station and the second mobile station within the neighbor cell transmit signals at different time points.

33. The system of claim 30, wherein the base station schedules the mobile station so as to reduce the number of subchannels allocated the mobile station and the second mobile station within the neighbor cell.

34. The system of claim 30, wherein the base station schedules the mobile station by changing modulation and coding scheme (MCS) levels of the mobile station and the second mobile station within the neighbor cell.