User equipment having channel quality indicator feedback mechanism

1. A user equipment (UE) comprising:

a transmitter for transmitting wireless data;

a receiver for receiving wireless data;

a processor coupled to the transmitter and the receiver and is configured for:

receiving via the receiver a signaling comprising a first information related to a channel quality indicator (CQI) threshold and a N×L precoding matrix having N rows and L columns with each of the N rows corresponding to an antenna port and each of the L columns corresponding to a user, wherein N and L are both integers greater than one;

obtaining from the first information the CQI threshold and the N×L precoding matrix;

performing a channel quality indicator (CQI) calculation for the L columns of the N×L precoding matrix;

determining from the CQI calculation for the L columns a preferred column that is above the CQI threshold; and

transmitting via the transmitter a second information indicating the preferred column.

2. The UE of claim 1 , wherein the processor is configured for transmitting via the transmitter the second information indicating the preferred column comprising:

transmitting via the transmitter the second information which comprises a bitmap indicating the preferred column which is higher than the CQI threshold.

3. The UE of claim 2 , wherein the bitmap is a L bits binary sequence representing the L columns sequentially with each bit of the L bits binary sequence representing a different column of the L columns.

4. The UE of claim 3 , wherein the each bit of the L bits binary sequence has a first state or a second state, and the first state indicates the preferred column that is above the CQI threshold.

5. A user equipment (UE) comprising:

a transmitter for transmitting wireless data;

a receiver for receiving wireless data;

a processor coupled to the transmitter and the receiver and is configured for:

receiving via the receiver a signaling comprising a first information related to a N×L precoding matrix having N rows and L columns with each of the N rows corresponding to an antenna port and each of the L columns corresponding to a user, wherein N and L are both integers greater than one;

obtaining from the first information the N×L precoding matrix;

performing a channel quality indicator (CQI) calculation for L columns of the N×L precoding matrix;

determining from the CQI calculation for the L column a preferred column which has the highest CQI;

calculating a hypothetical interference power by assuming the L columns except for the preferred column are used for transmission in order to generate an interference report; and

transmitting via the transmitter an index corresponding to the preferred column, the CQI using the preferred column, and the interference report.

6. The UE of claim 5 , wherein the index corresponding to the preferred column is represented by a binary value.

7. The UE of claim 5 , wherein the interference report comprises a (L−1) bits bitmap sequentially representing the L columns except for the preferred column with each bit of the (L−1) bits binary sequence representing a different column of the L columns other than the preferred column.

8. The UE of claim 7 , wherein each bit of the binary sequence has a first state and a second state, wherein the first state represents a column by which the lowest hypothetical interference power is calculated.

9. The UE of claim 7 , wherein each bit of the binary sequence has a first state and a second state, wherein the first state represents a column by which the highest hypothetical interference power is calculated.

10. The UE of claim 7 , wherein each bit of the binary sequence has a first state and a second state, wherein the first state represents a column by which the hypothetical interference power calculated is below a lower predefined threshold.

11. The UE of claim 7 , wherein each bit of the binary sequence has a first state and a second state, wherein the first state represents a column by which the hypothetical interference power calculated is above an upper predefined threshold.

12. A user equipment (UE) comprising:

a transmitter for transmitting wireless data;

a receiver for receiving wireless data;

a processor coupled to the transmitter and the receiver and is configured for:

receiving via the receiver a signaling comprising a first information related to a N×L precoding matrix having N rows and L columns with each of the N rows corresponding to an antenna port and each of the L columns corresponding to a user, wherein N and L are both integers greater than one;

obtaining from the first information the N×L precoding matrix;

selecting K of the L columns of the N×L precoding matrix, where 1<K≦L, and K is an integer and obtaining K CQIs corresponding to the selected K of the L columns; and

transmitting via the transmitter K indexes corresponding to K of the L columns and K CQIs corresponding to K of the L columns.

13. The UE of claim 12 , wherein the processor is configured for selecting K of the L columns of the N×L precoding matrix comprising:

selecting K of the L columns of the N×L precoding matrix having the best CQI by the UE.

14. The UE of claim 12 , wherein the processor is configured for selecting K of the L columns of the N×L precoding matrix comprising:

receiving information related to a configuration which determines K of the L columns over the receiver.

15. A user equipment (UE) comprising:

a transmitter for transmitting wireless data;

a receiver for receiving wireless data;

a processor coupled to the transmitter and the receiver and is configured for:

receiving via the receiver a signaling comprising a first information related to a N×L precoding matrix having N rows and L columns with each of the N rows corresponding to an antenna port and each of the L columns corresponding to a user, wherein N and L are both integers greater than one;

obtaining from the first information the N×L precoding matrix;

determining from the L columns a preferred column;

determining a first co-scheduling hypothesis comprising a first set of indexes of M of the L columns, where M is an integer and 1<M≦L, and the indexes of the M of the L columns represent columns to be concurrently used when the preferred column is used by the UE;

calculating a first CQI by using the preferred column and the first co-scheduling hypothesis; and

transmitting via the transmitter a second information indicating the preferred column, the first co-scheduling hypothesis, and the first CQI.

16. The UE of claim 15 , wherein before the processor is configured for receiving via the receiver the signaling comprising the first information related to the N×L precoding matrix, the processor is further configured for:

receiving from the receiver the indexes of M of the L columns for the first co-scheduling hypothesis.

17. The UE of claim 15 , wherein the processor is further configured for:

determining a second set of indexes of the M of the L columns represent columns to be concurrently used when the preferred column is used by the UE; and

calculating a second CQI by using the preferred column and the second co-scheduling hypothesis.

18. The UE of claim 15 , wherein an index corresponding to the preferred column is represented by a binary value.

19. The UE of claim 15 , wherein the first set of indexes of the M of the L columns is represented by a (L−1) bits bitmap sequentially representing the L columns except for the preferred column with each bit of the (L−1) bits binary sequence representing a different column of the L columns other than the preferred column.

20. The UE of claim 19 , wherein each of the (L−1) bits binary sequence has a first state and a second state, wherein the first state represents a column which is to be hypothetically assigned.