SCHEDULING ALGORITHMS FOR COOPERATIVE BEAMFORMING BASED ON RESOURCE QUALITY INDICATION

• US 20100195527A1
• Filed: 02/01/2010
• Published: 08/05/2010
• Est. Priority Date: 02/02/2009
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Borran, Jaber M., Gorokhov, Alexei Y.
• Granted Patent: US 8,867,493 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04B 7/0632 Channel quality parameters, e.g. channel quality indicator [CQI]
• CPC Class Codes: H04B 7/0634 Antenna weights or vector/matrix coefficients

Abstract

Certain aspects of the present disclosure support techniques for cooperative beamforming based on inter-cell coordination. Signaling design allows coordinated downlink transmissions with reduced inter-cell interference.

Claims

1. A method for wireless communications, comprising:

transmitting a reference signal comprising an indication about a beam direction for data transmission;

transmitting, to a set of user terminals, a request to send at least one indication message about quality of one or more communication resources associated with the user terminals;

receiving, from one or more user terminals from the set, one or more of the indication messages generated at least in part based on the reference signal; and

scheduling, based on the received indication messages, transmission of data to at least one of the user terminals from the set, the data are to be transmitted using the beam direction.

2. The method of claim 1, wherein the reference signal further indicates a power for the data transmission.

3. The method of claim 1, wherein:

the reference signal comprises resource elements associated with a resource unit in every transmission subframe, and

the reference signal is used to measure signal and interference energy corresponding to the resource unit.

4. The method of claim 1, further comprising:

selecting, based on the received indications, modulation-coding scheme (MCS) for the data transmission; and

transmitting the data using the MCS and the beam direction.

5. An apparatus for wireless communications, comprising:

a transmitter configured to transmitting a reference signal comprising an indication about a beam direction for data transmission, wherein

the transmitter is also configured to transmit, to a set of user terminals, a request to send at least one indication message about quality of one or more communication resources associated with the user terminals;

a receiver configured to receive, from one or more user terminals from the set, one or more of the indication messages generated at least in part based on the reference signal; and

a scheduler configured to schedule, based on the received indication messages, transmission of data to at least one of the user terminals from the set, the data are to be transmitted using the beam direction.

6. The apparatus of claim 5, wherein the reference signal further indicates a power for the data transmission.

7. The apparatus of claim 5, wherein:

the reference signal comprises resource elements associated with a resource unit in every transmission subframe, and

the reference signal is used to measure signal and interference energy corresponding to the resource unit.

8. The apparatus of claim 5, further comprising:

a circuit configured to select, based on the received indications, modulation-coding scheme (MCS) for the data transmission, wherein

the transmitter is also configured to transmit the data using the MCS and the beam direction.

9. An apparatus for wireless communications, comprising:

means for transmitting a reference signal comprising an indication about a beam direction for data transmission;

means for transmitting, to a set of user terminals, a request to send at least one indication message about quality of one or more communication resources associated with the user terminals;

means for receiving, from one or more user terminals from the set, one or more of the indication messages generated at least in part based on the reference signal; and

means for scheduling, based on the received indication messages, transmission of data to at least one of the user terminals from the set, the data are to be transmitted using the beam direction.

10. The apparatus of claim 9, further comprising:

means for selecting, based on the received indications, modulation-coding scheme (MCS) for the data transmission; and

means for transmitting the data using the MCS and the beam direction.

11. A computer-program product for wireless communications, comprising a computer readable medium having instructions stored thereon, the instructions being executable by one or more processors and the instructions comprising:

instructions for transmitting a reference signal comprising an indication about a beam direction for data transmission;

instructions for transmitting, to a set of user terminals, a request to send at least one indication message about quality of one or more communication resources associated with the user terminals;

instructions for receiving, from one or more user terminals from the set, one or more of the indication messages generated at least in part based on the reference signal; and

instructions for scheduling, based on the received indication messages, transmission of data to at least one of the user terminals from the set, the data are to be transmitted using the beam direction.

12. The computer-program product of claim 11, further comprising:

instructions for selecting, based on the received indications, modulation-coding scheme (MCS) for the data transmission; and

instructions for transmitting the data using the MCS and the beam direction.

13. An apparatus for wireless communications, comprising:

at least one processor configured to

transmit a reference signal comprising an indication about a beam direction for data transmission,

transmit, to a set of user terminals, a request to send at least one indication message about quality of one or more communication resources associated with the user terminals,

receive, from one or more user terminals from the set, one or more of the indication messages generated at least in part based on the reference signal, and

schedule, based on the received indication messages, transmission of data to at least one of the user terminals from the set, the data are to be transmitted using the beam direction; and

a memory coupled to the at least one processor.

14. The apparatus of claim 13, wherein the processor is further configured to:

select, based on the received indications, modulation-coding scheme (MCS) for the data transmission; and

transmit the data using the MCS and the beam direction.

15. A method for wireless communications, comprising:

receiving, from a serving cell at a user terminal, a reference signal comprising an indication about a beam direction of the serving cell to be used for data transmission;

measuring quality of a channel indicated in the reference signal, the channel being observed by the user terminal;

receiving, from the serving cell, a request to transmit an indication about the measured channel quality; and

in response to the request, transmitting the indication to the serving cell.

16. The method of claim 15, wherein the reference signal further indicates a transmit power determined by the serving cell.

17. The method of claim 15, wherein:

the reference signal comprises resource elements associated with a resource unit in every transmission subframe, and

the reference signal is used to measure signal and interference energy corresponding to the resource unit.

18. The method of claim 15, further comprising:

transmitting the measured channel quality to the serving cell.

19. An apparatus for wireless communications, comprising:

a receiver configured to receive, from a serving cell, a reference signal comprising an indication about a beam direction of the serving cell to be used for data transmission;

a circuit configured to measure quality of a channel indicated in the reference signal, the channel being observed by the apparatus, wherein

the receiver is also configured to receive, from the serving cell, a request to transmit an indication about the measured channel quality; and

a transmitter configured to transmit the indication to the serving cell in response to the request.

20. The apparatus of claim 19, wherein the reference signal further indicates a transmit power determined by the serving cell.

21. The apparatus of claim 19, wherein:

the reference signal comprises resource elements associated with a resource unit in every transmission subframe, and

the reference signal is used to measure signal and interference energy corresponding to the resource unit.

22. The apparatus of claim 19, wherein

the transmitter is also configured to transmit the measured channel quality to the serving cell.

23. An apparatus for wireless communications, comprising:

means for receiving, from a serving cell, a reference signal comprising an indication about a beam direction of the serving cell to be used for data transmission;

means for measuring quality of a channel indicated in the reference signal, the channel being observed by the apparatus;

means for receiving, from the serving cell, a request to transmit an indication about the measured channel quality; and

means for transmitting the indication to the serving cell in response to the request.

24. The apparatus of claim 23, further comprising:

means for transmitting the measured channel quality to the serving cell.

25. A computer-program product for wireless communications, comprising a computer readable medium having instructions stored thereon, the instructions being executable by one or more processors and the instructions comprising:

instructions for receiving, from a serving cell at a user terminal, a reference signal comprising an indication about a beam direction of the serving cell to be used for data transmission;

instructions for measuring quality of a channel indicated in the reference signal, the channel being observed by the user terminal;

instructions for receiving, from the serving cell, a request to transmit an indication about the measured channel quality; and

instructions for transmitting the indication to the serving cell in response to the request.

26. The computer-program product of claim 25, wherein the instructions further comprise:

instructions for transmitting the measured channel quality to the serving cell.

27. An apparatus for wireless communications, comprising:

at least one processor configured to

receive, from a serving cell, a reference signal comprising an indication about a beam direction of the serving cell to be used for data transmission;

measure quality of a channel indicated in the reference signal, the channel being observed by the apparatus;

receive, from the serving cell, a request to transmit an indication about the measured channel quality, and

transmit the indication to the serving cell in response to the request; and

a memory coupled to the at least one processor.

28. The apparatus of claim 27, wherein the processor is further configured to transmit the measured channel quality to the serving cell.