Multiple rank CQI feedback for cellular networks

• US 9,124,532 B2
• Filed: 06/02/2014
• Issued: 09/01/2015
• Est. Priority Date: 08/07/2009
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Chen, Runhua, Onggosanusi, Eko Nugroho
• Primary Examiner(s): CHO, HONG SOL
• Application Number:
  US14/293,152
• Publication Number:
  US 20140269395A1
• Time in Patent Office: 456 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H04B 7/024 Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/0434 using multiple eigenmodes
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04B 7/0478 Special codebook structures directed to feedback optimisation
• CPC Class Codes: H04B 7/063 Parameters other than those covered in groups H04B7/0623 - H04B7/0634, e.g. channel matrix rank or transmit mode selection
• 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
• CPC Class Codes: H04B 7/0639 Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection
• CPC Class Codes: H04L 43/50 Testing arrangements

Abstract

Single user and multiuser MIMO transmission in a cellular network may be performed by a base station (eNB) transmitting either one, two, or more transmission layers. A user equipment (UE) receives a reference symbol from the base station. The UE processes the reference symbol with one or more of a plurality of precoding matrices to form a plurality of channel quality indices (CQI). The UE provides feedback to the eNB comprising one or more feedback CQI selected from the plurality of CQI and one or more precoding matrix indicators (PMI) identifying the one or more precoding matrices used to form each of the one or more feedback CQIs for two or more ranks.

Claims

1. A user equipment device, comprising:

circuitry for receiving a first demodulation reference signal at the user equipment (UE) from a first base station (eNB);

circuitry for computing a plurality of channel quality indicators (CQI) for each of two or more ranks derived from at least the first demodulation reference signal with one or more of a plurality of precoding matrices; and

circuitry for transmitting feedback from the UE to the eNB comprising one or more CQI reports selected from the plurality of CQI for each of the two or more ranks, and one or more precoding matrix indicators (PMI) identifying the one or more precoding matrices used to form each of the one or more CQI reports.

2. The device of claim 1, wherein the UE is a mobile handset.

3. A user equipment device, comprising:

circuitry for receiving a first reference signal at the user equipment (UE) from a first base station (eNB);

circuitry for computing a plurality of channel quality indicators (CQI) for each of two or more ranks derived from at least the first reference signal with one or more of a plurality of precoding matrices, wherein each of the plurality of CQI is formed using a different combination of two or more of the plurality of precoding matrices; and

circuitry for transmitting feedback from the UE to the eNB comprising one or more CQI reports selected from the plurality of CQI for each of the two or more ranks, and one or more precoding matrix indicators (PMI) identifying the one or more precoding matrices used to form each of the one or more CQI reports, wherein the feedback for each of the two or more ranks comprises two or more PMI identifying the combination of precoding matrices used to form each of the one or more feedback CQI.

4. The device of claim 3, wherein each of the plurality of CQI reports corresponds to a precoding matrix recommended for the UE for each of the two or more ranks.

5. The device of claim 3, wherein each of the plurality of CQI reports corresponds to a precoding matrix recommended for the UE for each of the two or more ranks.

6. The device of claim 3, wherein the UE is a mobile handset.

7. A user equipment device, comprising:

circuitry for receiving a first reference signal at the user equipment (UE) from a first base station (eNB);

circuitry for computing a plurality of channel quality indicators (CQI) for each of two or more ranks derived from at least the first reference signal with one or more of a plurality of precoding matrices, wherein each of the plurality of CQI is formed using a different combination of two or more of the plurality of precoding matrices;

circuitry for calculating a correlation between each combination of precoding matrices and selecting for feedback only combinations having a lower correlation, wherein only combinations having a correlation below a selected threshold are selected for feedback; and

circuitry for transmitting feedback from the UE to the eNB comprising one or more CQI reports selected from the plurality of CQI for each of the two or more ranks, and one or more precoding matrix indicators (PMI) identifying the one or more precoding matrices used to form each of the one or more CQI reports, wherein the feedback for each of the two or more ranks comprises two or more PMI identifying the combination of precoding matrices used to form each of the one or more feedback CQI.

8. The device of claim 7, wherein each of the plurality of CQI reports corresponds to a precoding matrix recommended for the UE for each of the two or more ranks.

9. The device of claim 7, wherein the UE is a mobile handset.

10. A user equipment device, comprising:

circuitry for receiving a first reference signal at the user equipment (UE) from a first base station (eNB);

circuitry for computing a plurality of channel quality indicators (CQI) for each of two or more ranks derived from at least the first reference signal with one or more of a plurality of precoding matrices;

circuitry for calculating a distance between each combination of preceding matrices and selecting for feedback only combinations having a larger distance; and

circuitry for transmitting feedback from the UE to the eNB comprising one or more CQI reports selected from the plurality of CQI for each of the two or more ranks, and one or more precoding matrix indicators (PMI) identifying the one or more precoding matrices used to form

11. The device of claim 10, wherein each of the plurality of CQI reports corresponds to a precoding matrix recommended for the UE for each of the two or more ranks.

12. The device of claim 10, wherein the UE is a mobile handset.

13. A user equipment device, comprising;

circuitry for receiving a first reference signal (RS) at the user equipment (UE) from a first base station (eNB);

circuitry for receiving a second reference symbol from a second eNB coincidently with receiving the first reference signal;

circuitry for computing a plurality of channel quality indicators (CQI) for each of two or more ranks derived from at least the first reference signal with one or more of a plurality of precoding matrices, wherein the computing comprises forming one or more CQI for each of the first RS and the second RS for each of the two or more ranks using one or more of a portion of the plurality of precoding matrices; and

circuitry for transmitting feedback from the UE to the eNB comprising one or more CQI reports selected from the plurality of CQI for each of the two or more ranks, and one or more precoding matrix indicators (PMI) identifying the one or more precoding matrices used to form each of the one or more CQI reports, wherein the feedback comprises one or more feedback CQI and PMI selected for the first RS and one or more feedback CQI and PMI selected for the second RS for each of the two or more ranks.

14. The device of claim 13, wherein each of the plurality of CQI reports corresponds to a precoding matrix recommended for the UE for each of the two or more ranks.

15. The device of claim 13, wherein the UE is a mobile handset.