Double search user group selection scheme with range reduction for FDD multiuser MIMO downlink transmission with finite-rate channel state information feedback

• US 20070066238A1
• Filed: 09/21/2005
• Published: 03/22/2007
• Est. Priority Date: 09/21/2005
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Zhang, Chengjin, Zheng, Jun, Rooyen, Pieter
• Granted Patent: US 7,636,553 B2
• Time in Patent Office: Days
• US Class Current: 455/69
• CPC Class Codes: H04B 7/0408 using two or more beams, i.e. beam diversity
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0626 Channel coefficients, e.g. channel state information [CSI]

Abstract

Aspects of a double search user group selection scheme with range reduction for FDD multiuser MIMO downlink transmission with finite-rate channel state information feedback are provided. The method may comprise maximizing system capacity using feedback information for a plurality of signals in a frequency division duplex system to reduce a search range within which a group of signals having maximum channel gain are located. The feedback information may comprise quantized gain for the signals. Quantized channel direction for the signals within the reduced search range may be requested and received by the transmitter. One or two signals from the reduced search range that maximizes system capacity may be selected. The receivers associated with these signals may then be selected as the user group.

Claims

1. A method for processing signals in a communication system, the method comprising maximizing system capacity using feedback information for a plurality of signals in a frequency division duplex system to reduce a search range within which a group of signals having maximum channel gain are located.

2. The method according to claim 1, wherein said feedback information comprises quantized gain for said plurality of signals.

3. The method according to claim 2, further comprising requesting quantized channel information for signals within said reduced search range.

4. The method according to claim 3, wherein said requested quantized channel information comprises quantized channel direction for said signals within said reduced search range.

5. The method according to claim 1, further comprising receiving quantized channel direction for said signals within said reduced search range.

6. The method according to claim 5, further comprising:

selecting, from a plurality of signals within said reduced search range, a first signal corresponding to a channel gain that is greater than a channel gain corresponding to a remaining portion of said plurality of signals within said reduced search range;

selecting, from said remaining portion of said plurality of signals within said reduced search range, a second signal corresponding to a channel gain that is greater than a channel gain corresponding to a remaining portion of said remaining portion of said plurality of signals within said reduced search range; and

maximizing said system capacity based on said selected first signal and said selected second signal.

7. The method according to claim 6, further comprising maximizing a first system capacity based on said channel gain corresponding to said selected first signal.

8. The method according to claim 7, further comprising selecting a first pair of receivers associated with said maximized first system capacity.

9. The method according to claim 6, further comprising maximizing a second system capacity based on said channel gain corresponding to said selected second signal.

10. The method according to claim 9, further comprising selecting a second pair of receivers associated with said maximized first system capacity.

11. The method according to claim 6, further comprising maximizing said system capacity based on a greater of a maximized first system capacity and a maximized second system capacity.

12. The method according to claim 11, further comprising selecting a pair of receivers that provide said maximized system capacity.

13. A system for processing signals in a communication system, the system comprising circuitry that maximizes system capacity using feedback information for a plurality of signals in a frequency division duplex system to reduce a search range within which a group of signals having maximum channel gain are located.

14. The system according to claim 13, wherein said feedback information comprises quantized gain for said plurality of signals.

15. The system according to claim 14, further comprising circuitry that requests quantized channel information for signals within said reduced search range.

16. The system according to claim 15, wherein said requested quantized channel information comprises quantized channel direction for said signals within said reduced search range.

17. The system according to claim 13, further comprising circuitry that receives quantized channel direction for said signals within said reduced search range.

18. The system according to claim 17, further comprising:

circuitry that selects, from a plurality of signals within said reduced search range, a first signal corresponding to a channel gain that is greater than a channel gain corresponding to a remaining portion of said plurality of signals within said reduced search range;

said circuitry selects, from said remaining portion of said plurality of signals within said reduced search range, a second signal corresponding to a channel gain that is greater than a channel gain corresponding to a remaining portion of said remaining portion of said plurality of signals within said reduced search range; and

said circuitry maximizes said system capacity based on said selected first signal and said selected second signal.

19. The system according to claim 18, wherein said circuitry maximizes a first system capacity based on said channel gain corresponding to said selected first signal.

20. The system according to claim 19, wherein said circuitry selects a first pair of receivers associated with said maximized first system capacity.

21. The system according to claim 18, wherein said circuitry maximizes a second system capacity based on said channel gain corresponding to said selected second signal.

22. The system according to claim 21, wherein said circuitry selects a second pair of receivers associated with said maximized first system capacity.

23. The system according to claim 18, wherein said circuitry maximizes said system capacity based on a greater of a maximized first system capacity and a maximized second system capacity.

24. The system according to claim 23, wherein said circuitry selects a pair of receivers that provide said maximized system capacity.

25. The system according to claim 23, wherein said circuitry comprises at least one of the following:

a scheduler and a processor.