RANK AND PMI IN DOWNLOAD CONTROL SIGNALING FOR UPLINK SINGLE-USER MIMO (UL SU-MIMO)

• US 20090262695A1
• Filed: 04/15/2009
• Published: 10/22/2009
• Est. Priority Date: 04/22/2008
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Onggosanusi, Eko N., Chen, Runhua
• Granted Patent: US 8,811,353 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04L 1/0031 Multiple signaling transmission H04L1/1664, F15 take precedence
• CPC Class Codes: H04L 2025/03426 transmission using multiple-input and multiple-output channels
• CPC Class Codes: H04L 2025/03802 Signalling on the reverse channel
• CPC Class Codes: H04L 25/03343 Arrangements at the transmitter end
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04W 72/563 of the wireless resources

Abstract

A method of operating a user equipment device includes extracting at least one rank indicator (RI) from an uplink grant, and adapting a transmission rank in response to said RI. At least two transmit antennas are configured to transmit according to said transmission rank.

Claims

1. A method of operating a user equipment device, comprising:

extracting at least one rank indicator (RI) from an uplink grant;

adapting a transmission rank in response to said RI; and

configuring at least two transmit antennas to transmit according to said transmission rank.

2. The method of claim 1, further comprising extracting at least one pre-coding matrix indicator (PMI) from said uplink grant.

3. The method of claim 2, wherein said RI is jointly coded with said PMI.

4. The method of claim 2, wherein said at least one PMI is a single wideband PMI.

5. The method of claim 2, wherein said at least one PMI is at least two PMIs, wherein a first PMI is associated with a set of P sub-bands allocated by said grant, and a second PMI is associated with at least one sub-band of said set of P allocated sub-bands.

6. The method of claim 5, wherein said second PMI is associated with a selected subset of said set of P allocated sub-bands.

7. The method of claim 6, wherein said selected subset has a higher signal-to-interference plus noise ratio than a remaining subset of said sub-bands.

8. The method of claim 6, wherein said uplink grant includes a position indicator representing a position of said selected subset within said set of P allocated sub-bands.

9. The method of claim 5, wherein said second PMI is encoded differentially with respect to said first PMI using fewer bits than said first PMI.

10. The method of claim 9, wherein said second PMI is encoded using fewer bits than said first PMI.

11. A method of operating a base station having at least two receive antennas, comprising:

receiving a reference signal;

generating at least one rank indicator (RI) in response to said receiving; and

transmitting an uplink grant including said RI.

12. The method of claim 11, further comprising generating at least one pre-coding matrix indicator (PMI) and including said PMI in said uplink grant.

13. The method of claim 12, further comprising jointly encoding said RI and PMI.

14. The method of claim 12, wherein said at least one PMI is a single wideband PMI.

15. The method of claim 12, wherein said at least one PMI includes at least two PMIs, wherein a first PMI is associated with a set of P sub-bands allocated by said grant, and a second PMI is associated with at least one sub-band of said set of P allocated sub-bands.

16. The method of claim 15, wherein said second PMI is associated with a selected subset of said set of P allocated sub-bands.

17. The method of claim 16, wherein said selected subset has a higher signal-to-interference plus noise ratio than a remaining subset of said sub-bands.

18. The method of claim 16, wherein said uplink grant includes a position indicator representing a position of said selected subset within said set of P allocated sub-bands.

19. The method of claim 15, wherein said second PMI is encoded differentially with respect to said first PMI.

20. The method of claim 19, wherein said second PMI is encoded using fewer bits than said first PMI.