Data transmission and power control in a multihop relay communication system

• US 8,417,255 B2
• Filed: 03/05/2008
• Issued: 04/09/2013
• Est. Priority Date: 03/16/2007
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Dayal, Pranav, Ji, Tingfang
• Primary Examiner(s): FARAGALLA, MICHAEL A
• Application Number:
  US12/042,901
• Publication Number:
  US 20080227461A1
• Time in Patent Office: 1,861 Days
• Field of Search: 455/452.2, 455436-444, 455/453, 455/450, 455/518, 455/432.2, 370/328, 370/329, 370/338, 370/389, 370/311, 370/331
• 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:

a memory coupled to at least one processor;

the at least one processor configured to;

estimate link quality based on a transmission received from a first station;

generate first channel quality information (CQI) based on the estimated link quality;

send the first CQI to the first station;

receive second CQI from a second station, the second CQI being different from the first CQI;

receive data sent by the first station according to a first transmission schedule determined by the first station, the first transmission schedule comprising an allocation of radio resources based on the first CQI;

identify a second transmission schedule for transmissions to the second station based on the second CQI, the second transmission schedule comprising an allocation of radio resources to the second station based on the second CQI; and

send the data to the second station using the allocated radio resources based on the second transmission schedule based on the second CQI.

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 according to the first transmission schedule based on the first CQI, and wherein the at least one processor is configured to schedule transmission of the data to the second station according to the second transmission schedule 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.

26. The apparatus of claim 1, wherein the operation of identifying the second transmission schedule comprising an allocation of the radio resources to the second station comprises the at least one processor being further configured to:

analyze the second CQI; and

determine the second transmission schedule comprising the allocation of the radio resources for the second station based on the analysis of the second CQI.

27. The apparatus of claim 1, wherein the operation of identifying the second transmission schedule comprising an allocation of the radio resources to the second station comprises the at least one processor being further configured to:

transmit the second CQI to the first station; and

receive the second transmission schedule comprising the allocation of the radio resources for the second station from the first station.

7. A method for wireless communication, comprising:

estimating link quality based on a transmission received from a first station;

generating first channel quality information (CQI) based on the estimated link quality;

sending the first CQI to the first station;

receiving second CQI from a second station, the second CQI being different from the first CQI;

receiving data sent by the first station according to a first transmission schedule determined by the first station, the first transmission schedule comprising an allocation of radio resources based on the first CQI;

identifying a second transmission schedule for transmissions to the second station based on the second CQI, the second transmission schedule comprising an allocation of radio resources to the second station based on the second CQI; and

sending the data to the second station using the allocated radio resources based on the second transmission schedule 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 according to the second transmission schedule based on the second CQI.

28. The method of claim 7, wherein identifying the second transmission schedule comprising an allocation of the radio resources to the second station further comprises:

analyzing the second CQI; and

determining the second transmission schedule comprising the allocation of the radio resources for the second station based on the analysis of the second CQI.

29. The method of claim 7, wherein identifying the second transmission schedule comprising an allocation of the radio resources to the second station further comprises:

transmitting the second CQI to the first station; and

receiving the second transmission schedule comprising the allocation of the radio resources for the second station from the first station.

10. An apparatus for wireless communication, comprising:

means for estimating link quality based on a transmission received from a first station;

means for generating first channel quality information (CQI) based on the estimated link quality;

means for sending the first CQI to the first station;

means for receiving second CQI from a second station, the second CQI being different from the first CQI;

means for receiving data sent by the first station according to a first transmission schedule determined by the first station, the first transmission schedule comprising an allocation of radio resources based on the first CQI;

means for identifying a second transmission schedule for transmissions to the second station based on the second CQI, the second transmission schedule comprising an allocation of radio resources to the second station based on the second CQI; and

means for sending the data to the second station using the allocated radio resources based on the second transmission schedule 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 according to the second transmission schedule based on the second CQI.

13. A computer program product, comprising:

a non-transitory computer-readable storage medium comprising;

code for causing at least one computer to estimate link quality based on a transmission received from a first station;

code for causing the at least one computer to generate first channel quality information (CQI) based on the estimated link quality;

code for causing the at least one computer to send the first CQI to the first station;

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

code for causing at least one computer to receive data sent by the first station according to a first transmission schedule determined by the first station, the first transmission schedule comprising an allocation of radio resources based on the first CQI;

code for causing at least one computer to identify a second transmission schedule for transmissions to the second station based on the second CQI, the second transmission schedule comprising an allocation of radio resources to the second station based on the second CQI; and

code for causing the at least one computer to send the data to the second station using the allocated radio resources based on the second transmission schedule 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 according to the second transmission schedule based on the second CQI.

15. An apparatus for wireless communication, comprising:

a memory coupled to at least one processor;

the at least one processor configured to;

send a pilot to a relay station;

receive first channel quality information (CQI) generated by the relay station based on the pilot;

generate a first transmission schedule comprising an allocation of radio resources to the relay station based on the first CQI; and

send data to the relay station using the allocated radio resources based on the first CQI, the data being sent by the relay station to a subscriber station according to a second transmission schedule comprising an allocation of radio resources to the subscriber station based on second CQI sent by the subscriber station to the relay station.

16. An apparatus for wireless communication, comprising:

a memory coupled to at least one processor;

the at least one processor configured to;

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

receive second CQI from a second station, the second CQI being different from the first CQI;

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

receive data sent by the first station according to a first transmission schedule determined by the first station, the first transmission schedule comprising an allocation of radio resources based on the first CQI;

receive a second transmission schedule from and determined by the first station based on the second CQI, the second transmission schedule identifying a radio resource to allocate to the second station; and

send the data to the second station based on the second transmission schedule determined based on the second CQI.

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 according to the first transmission schedule based on the first CQI and generates the second transmission schedule based on the second CQI.

20. The apparatus of claim 16, wherein the second transmission schedule 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, the second CQI being different from the first CQI;

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

receiving data sent by the first station according to a first transmission schedule determined by the first station, the first transmission schedule comprising an allocation of radio resources based on the first CQI;

receiving a second transmission schedule from and determined by the first station based on the second CQI, the second transmission schedule identifying a radio resource to allocate to the second station; and

sending the data to the second station based on the second transmission schedule 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 according to the first transmission schedule based on the first CQI and the second transmission schedule is generated by the base station based on the second CQI.

25. An apparatus for wireless communication, comprising:

a memory coupled to the at least one processor;

the at least one processor configured to;

send a pilot to a relay station;

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, the second CQI being different from the first CQI;

determine a transmission schedule based on the second CQI, the transmission schedule comprising an allocation of radio resources to allocate to the subscriber station;

send data to the relay station based on the first CQI; and

send the transmission schedule to the relay station, the data being sent by the relay station to the subscriber station based on the transmission schedule.