Method and apparatus for CSI reporting on PUCCH

1. A user equipment (UE) for channel state information (CSI) reporting in a wireless communication system, the UE comprising:

a transceiver configured to receive CSI reporting configuration information; and

at least one processor operably connected to the transceiver, the at least one processor configured to:

generate a CSI report comprising a precoding matrix indicator (PMI) and a CSI-RS resource indicator (CRI) based on the CSI reporting configuration information;

determine a CSI report set comprising a first subset and a second subset based on the CSI reporting configuration information that is used for the CSI report;

determine a number of bits of a payload included in the CSI report for the first subset and the second subset included in the CSI report set; and

if the payload is greater than an allowable number of bits, select a first uplink (UL) channel as a first physical uplink control channel (PUCCH) format for the first subset and select a second UL channel as a second PUCCH format for the second subset to transmit the CSI report,

wherein the first subset includes at least a first part of the PMI and the second subset includes at least a second part of the PMI, and

wherein the transceiver is further configured to transmit the first and second subset using the selected UL channels.

2. The UE of claim 1 , wherein the first UL channel comprises a PUCCH format 2 and the second UL channel comprises a PUCCH format 3.

3. The UE of claim 1 , wherein the allowable number of bits corresponds to a maximum number of bits included in the PUCCH format 1.

4. The UE of claim 1 , wherein, to transmit the first and second subset using the selected UL channels, the transceiver is further configured to:

transmit the first UL channel comprising the first subset or the second subset included in the CSI report set that includes the CRI, if the number of bits of the payload included in the CSI report is smaller than or equal to the allowable number of bits, wherein the first UL channel comprises the PUCCH format 1; and

transmit the second UL channel comprising the first subset or the second subset included in the CSI report set that includes the CRI, if the number of bits of the payload included in the CSI report is greater than the allowable number of bits, wherein the second UL channel comprises the PUCCH format 2.

5. The UE of claim 1 , wherein each of the first subset and the second subset included in the CSI report set is configured to be reported using either a same PUCCH Format including at least one of a PUCCH format 2 or PUCCH Format 3, or a different PUCCH Format including at least one of the PUCCH format 2 or the PUCCH Format 3.

6. The UE of claim 1 , wherein each of the first subset and the second subset included in the CSI report set comprises different CSI reports in accordance with the number of bits of the payload included in the CSI report.

7. The UE of claim 1 , wherein each of the first subset and the second subset included in the CSI report set is transmitted over different subframes, each of the different subframes comprising at least one subframe.

8. The UE of claim 1 , wherein:

the at least one processor is further configured to:

map the first subset to a first enhanced multi-input-multi-output (eMIMO)-Type and the second subset to a second eMIMO-Type; and

the transceiver is further configured to report each of the first subset associated with the first eMIMO-Type and the second subset associated with the second eMIMO-Type using a PUCCH format 2 if the payload is smaller than or equal to the allowable number of bits or a PUCCH format 3 if the payload is greater than the allowable number of bits.

9. The UE of claim 1 , wherein the first UL channel comprises the PUCCH format 1 and the second UL channel comprises a PUSCH format 2.

10. An eNodeB (eNB) for channel state information (CSI) reporting in a wireless communication system, the eNB comprising:

a transceiver configured to:

transmit CSI reporting configuration information; and

receive, from a user equipment (UE), a CSI report including a precoding matrix indicator (PMI) and a CSI resource indicator (CRI) based on the CSI reporting configuration information, wherein the CSI report comprises a CSI report set that includes a first subset and a second subset determined based on the transmitted CSI reporting configuration information; and

at least one processor operably connected to the transceiver, the at least one processor configured to determine a number of bits of a payload included in the CSI report for the first subset and the second subset included in the CSI report set,

wherein,

if the payload is greater than an allowable number of bits, the CSI report is received on a first uplink (UL) channel as a first physical uplink control channel (PUCCH) format for the first subset and a second UL channel as a second PUCCH format for the second subset,

wherein the first subset includes at least a first part of the PMI and the second subset includes at least a second part of the PMI.

11. The eNB of claim 10 , wherein the first UL channel comprises a PUCCH format 2 and the second UL channel comprises a PUCCH format 3, and wherein the allowable number of bits corresponds to a maximum number of bits included in the PUCCH.

12. The eNB of claim 10 , wherein the transceiver is further configured to:

receive the first UL channel comprising the first subset or the second subset included in the CSI report set that includes the CRI, if the number of bits of the payload include in the CSI report is smaller than or equal to the allowable number of bits, wherein the first UL channel comprises the PUCCH format 1; and

receive the second UL channel comprising the first subset or the second subset included in the CSI report set that includes the CRI, if the number of bits of the payload included in the CSI report is greater than the allowable number of bits, wherein the second UL channel comprises the PUCCH format 2.

13. The eNB of claim 10 , wherein:

the transceiver is further configured to receive each of a first subset associated with a first enhanced multi-input-multi-output (eMIMO)-Type and a second subset associated with a second eMIMO-Type using a PUCCH format 2 if the payload is smaller than or equal to the allowable number of bits, or a PUCCH format 3 if the payload is greater than the allowable number of bits respectively; and

the at least one processor is further configured to

map the first subset to the first eMIMO-Type and the second subset to the second eMIMO-Type.

14. The eNB of claim 10 , wherein the first UL channel comprises the PUCCH format 1 and the second UL channel comprises a PUSCH format 2.

15. A method of a user equipment (UE) for channel state information (CSI) reporting in a wireless communication system, the method comprising:

receiving CSI reporting configuration information;

generating a CSI report comprising a precoding matrix indicator (PMI) and a CSI-RS resource indicator (CRI) based on the CSI reporting configuration information;

determining a CSI report set comprising a first subset and a second subset based on the CSI reporting configuration information that is used for the CSI report;

determining a number of bits of a payload included in the CSI report for the first subset and the second subset included in the CSI report set;

if the payload is greater than an allowable number of bits, selecting a first uplink (UL) channel as a first physical uplink control channel (PUCCH) format for the first subset and selecting a second UL channel as a second PUCCH format for the second subset to transmit the CSI report, wherein the first subset includes at least a first part of the PMI and the second subset includes at least a second part of the PMI; and

transmitting the first and second subset using the selected UL channels.

16. The method of claim 15 , wherein the first UL channel comprises a PUCCH format 2 and the second UL channel comprises a PUCCH format 3.

17. The method of claim 15 , wherein the allowable number of bits corresponds to a maximum number of bits included in the PUCCH format 1.

18. The method of claim 15 , wherein transmitting the first and second subset using the selected UL channels comprises:

transmitting the first UL channel comprising the first subset or the second subset included in the CSI report set that includes the CRI, if the number of bits of the payload included in the CSI report is smaller than or equal to the allowable number of bits, wherein the first UL channel comprises the PUCCH format 1; and

transmitting the second UL channel comprising the first subset or the second subset included in the CSI report set that includes the CRI, if the number of bits of the payload included in the CSI report is greater than the allowable number of bits, wherein the second UL channel comprises a PUCCH format 2.

19. The method of claim 15 , wherein the first UL channel comprises the PUCCH format 1 and the second UL channel comprises a PUSCH format 2.