DATA TRANSMISSION AND POWER CONTROL IN A MULTIHOP RELAY COMMUNICATION SYSTEM

• US 20080227461A1
• Filed: 03/05/2008
• Published: 09/18/2008
• Est. Priority Date: 03/16/2007
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Dayal, Pranav, Ji, Tingfang
• Granted Patent: US 8,417,255 B2
• Time in Patent Office: Days
• US Class Current: 455/452.2
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 2001/0092 Error control systems characterised by the topology of the transmission link
• CPC Class Codes: H04W 72/04 Wireless resource allocation

Abstract

Techniques for transmitting data with distributed and centralized scheduling in a multihop relay communication system are described. For distributed scheduling, a relay station may generate and send first channel quality information (CQI) to a base station and receive second CQI from a subscriber station. The relay station may receive data sent by the base station based on the first CQI and may resend the data to the subscriber station based on the second CQI. For centralized scheduling, the relay station may generate first CQI for the base station, receive second CQI from the subscriber station, and send both CQIs to the base station. The relay station may receive data sent by the base station based on the first CQI and may resend the data to the subscriber station based on a scheduling decision determined based on the second CQI. Techniques for distributed and centralized power control are also described.

Claims

1. An apparatus for wireless communication, comprising:

at least one processor configured to send first channel quality information (CQI) to a first station, to receive second CQI from a second station, to receive data sent by the first station based on the first CQI, and to resend the data to the second station based on the second CQI; and

a memory coupled to the at least one processor.

2. The apparatus of claim 1, wherein the at least one processor is configured to receive pilot from the first station, to estimate link quality for the first station based on the pilot, and to generate the first CQI based on the estimated link quality for the first station.

3. The apparatus of claim 1, wherein the at least one processor is configured to send pilot to the second station and to receive the second CQI generated by the second station based on the pilot.

4. The apparatus of claim 1, wherein the first station schedules transmission of the data from the first station based on the first CQI, and wherein the at least one processor is configured to schedule transmission of the data to the second station based on the second CQI.

5. The apparatus of claim 4, wherein the at least one processor is configured to perform at least one of assigning radio resources to the second station and selecting a modulation and coding scheme for the second station based on the second CQI to schedule transmission of the data to the second station.

6. The apparatus of claim 1, wherein the first station is a base station and the second station is a subscriber station.

7. A method for wireless communication, comprising:

sending first channel quality information (CQI) to a first station;

receiving second CQI from a second station;

receiving data sent by the first station based on the first CQI; and

resending the data to the second station based on the second CQI.

8. The method of claim 7, further comprising:

receiving a first pilot from the first station; and

sending a second pilot to the second station, and

wherein the first CQI is generated based on the first pilot and the second CQI is generated based on the second pilot.

9. The method of claim 7, further comprising:

scheduling transmission of the data to the second station based on the second CQI.

10. An apparatus for wireless communication, comprising:

means for sending first channel quality information (CQI) to a first station;

means for receiving second CQI from a second station;

means for receiving data sent by the first station based on the first CQI; and

means for resending the data to the second station based on the second CQI.

11. The apparatus of claim 10, further comprising:

means for receiving a first pilot from the first station; and

means for sending a second pilot to the second station, and

wherein the first CQI is generated based on the first pilot and the second CQI is generated based on the second pilot.

12. The apparatus of claim 10, further comprising:

means for scheduling transmission of the data to the second station based on the second CQI.

13. A computer program product, comprising:

a computer-readable medium comprising;

code for causing at least one computer to send first channel quality information (CQI) to a first station;

code for causing the at least one computer to receive second CQI from a second station;

code for causing at least one computer to receive data sent by the first station based on the first CQI; and

code for causing the at least one computer to resend the data to the second station based on the second CQI.

14. The computer program product of claim 13, wherein the computer-readable medium further comprises:

code for causing the at least one computer to schedule transmission of the data to the second station based on the second CQI.

15. An apparatus for wireless communication, comprising:

at least one processor configured to send a pilot to a relay station, to receive first channel quality information (CQI) generated by the relay station based on the pilot, and to send data to the relay station based on the first CQI, the data being resent by the relay station to a subscriber station based on second CQI sent by the subscriber station to the relay station; and

a memory coupled to the at least one processor.

16. An apparatus for wireless communication, comprising:

at least one processor configured to generate first channel quality information (CQI) for a first station, to receive second CQI from a second station, to send the first CQI and the second CQI to the first station, to receive data sent by the first station based on the first CQI, and to resend the data to the second station based on a scheduling decision determined based on the second CQI; and

a memory coupled to the at least one processor.

17. The apparatus of claim 16, wherein the at least one processor is configured to receive pilot from the first station, to estimate link quality for the first station based on the pilot, and to generate the first CQI based on the estimated link quality for the first station.

18. The apparatus of claim 16, wherein the at least one processor is configured to send pilot to the second station, and to receive the second CQI generated by the second station based on the pilot.

19. The apparatus of claim 16, wherein the first station schedules transmission of the data from the first station based on the first CQI and generates the scheduling decision based on the second CQI.

20. The apparatus of claim 16, wherein the scheduling decision comprises at least one of radio resources assigned to the second station and a modulation and coding scheme selected for the second station.

21. The apparatus of claim 16, wherein the first station is a base station and the second station is a subscriber station.

22. A method for wireless communication, comprising:

generating first channel quality information (CQI) for a first station;

receiving second CQI from a second station;

sending the first CQI and the second CQI to the first station;

receiving data sent by the first station based on the first CQI; and

resending the data to the second station based on a scheduling decision determined based on the second CQI.

23. The method of claim 22, further comprising:

receiving a first pilot from the first station; and

sending a second pilot to the second station, and

wherein the first CQI is generated based on the first pilot and the second CQI is generated based on the second pilot.

24. The method of claim 22, wherein transmission of the data from the first station is scheduled by a base station based on the first CQI and the scheduling decision is generated by the base station based on the second CQI.

25. An apparatus for wireless communication, comprising:

at least one processor configured to send a pilot to a relay station, to receive first channel quality information (CQI) and second CQI from the relay station, the first CQI being generated based on the pilot, and the second CQI being sent by a subscriber station to the relay station, to determine a scheduling decision based on the second CQI, to send data to the relay station based on the first CQI, and to send the scheduling decision to the relay station, the data being resent by the relay station to the subscriber station based on the scheduling decision; and

a memory coupled to the at least one processor.

26. An apparatus for wireless communication, comprising:

at least one processor configured to receive a first transmission from a first station, to generate a first power adjustment based on the first transmission, to send the first power adjustment to the first station, to send a second transmission to a second station, to receive a second power adjustment generated by the second station based on the second transmission, to receive data sent by the first station at transmit power determined based on the first power adjustment, and to resend the data to the second station at transmit power determined based on the second power adjustment; and

a memory coupled to the at least one processor.

27. The apparatus of claim 26, wherein the at least one processor is configured to estimate link quality for the first station based on the first transmission, and to generate the first power adjustment based on the estimated link quality for the first station.

28. The apparatus of claim 26, wherein the at least one processor is configured to receive the first transmission on a first channel quality information channel (CQICH) from the first station, and to send the second transmission on a second CQICH to the second station.

29. The apparatus of claim 26, wherein the first station is a subscriber station and the second station is a base station.

30. A method for wireless communication, comprising:

receiving a first transmission from a first station;

generating a first power adjustment based on the first transmission;

sending the first power adjustment to the first station;

sending a second transmission to a second station;

receiving a second power adjustment generated by the second station based on the second transmission;

receiving data sent by the first station at transmit power determined based on the first power adjustment; and

resending the data to the second station at transmit power determined based on the second power adjustment.

31. The method of claim 30, wherein the generating the first power adjustment comprises

estimating link quality for the first station based on the first transmission, and

generating the first power adjustment based on the estimated link quality for the first station.

32. The method of claim 30, wherein the receiving the first transmission comprises receiving the first transmission on a first channel quality information channel (CQICH) from the first station, and wherein the sending the second transmission comprises sending the second transmission on a second CQICH to the second station.

33. An apparatus for wireless communication, comprising:

at least one processor configured to receive a transmission from a relay station, to generate a power adjustment based on the received transmission, to send the power adjustment to the relay station, and to receive data from the relay station, the data being sent by a subscriber station to the relay station and resent by the relay station at transmit power determined based on the power adjustment; and

a memory coupled to the at least one processor.

34. An apparatus for wireless communication, comprising:

at least one processor configured to receive a first transmission from a first station, to estimate link quality for the first station based on the first transmission, to send the estimated link quality for the first station and a second transmission to a second station, to receive first and second power adjustments from the second station, the first power adjustment being generated based on the estimated link quality for the first station, and the second power adjustment being generated based on the second transmission, to send the first power adjustment to the first station, to receive data sent by the first station at transmit power determined based on the first power adjustment, and to resend the data to the second station at transmit power determined based on the second power adjustment; and

a memory coupled to the at least one processor.

35. The apparatus of claim 34, wherein the at least one processor is configured to receive the first transmission on a first channel quality information channel (CQICH) from the first station, and to send the second transmission on a second CQICH to the second station.

36. The apparatus of claim 34, wherein the at least one processor is configured to send the estimated link quality for the first station on a channel quality information channel (CQICH), on a feedback channel, or in a Medium Access Control (MAC) management message to the second station.

37. The apparatus of claim 34, wherein the first station is a subscriber station and the second station is a base station.

38. A method for wireless communication, comprising:

receiving a first transmission from a first station;

estimating link quality for the first station based on the first transmission;

sending the estimated link quality for the first station and a second transmission to a second station;

receiving first and second power adjustments from the second station, the first power adjustment being generated based on the estimated link quality for the first station, and the second power adjustment being generated based on the second transmission;

sending the first power adjustment to the first station;

receiving data sent by the first station at transmit power determined based on the first power adjustment; and

resending the data to the second station at transmit power determined based on the second power adjustment.

39. The method of claim 38, wherein the receiving the first transmission comprises receiving the first transmission on a first channel quality information channel (CQICH) from the first station, and wherein the sending the second transmission comprises sending the second transmission on a second CQICH to the second station.

40. An apparatus for wireless communication, comprising:

at least one processor configured to receive a transmission from a relay station, to receive estimated link quality for a subscriber station from the relay station, to generate a first power adjustment based on the estimated link quality for the subscriber station, to generate a second power adjustment based on the transmission received from the relay station, to send the first and second power adjustments to the relay station, and to receive data from the relay station, the data being sent by the subscriber station at transmit power determined based on the first power adjustment and resent by the relay station at transmit power determined based on the second power adjustment; and

a memory coupled to the at least one processor.