Multiple rank CQI feedback for cellular networks

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.