Method and apparatus for reporting channel state information in a wireless communication system

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

receiving configuration information related to reporting of the CSI from a base station,

wherein the configuration information includes parameters related to omission of the CSI, and

wherein the CSI comprises (i) a first part used to identify a number of information bits of a second part of the CSI and (ii) the second part;

receiving downlink control information(DCI) including information regarding a coding rate of the CSI from the base station;

receiving a first reference signal for channel measurement;

measuring a channel based on the first reference signal; and

reporting the CSI of the measured channel through a physical uplink shared channel (PUSCH) to the base station,

wherein the second part of the CSI includes a wideband CSI and a subband CSI,

wherein the wideband CSI included in the second part of the CSI has a higher priority than the subband CSI included in the second part of the CSI,

wherein some or all of the second part of the CSI is omitted based on a coding rate of the second part being greater than a threshold value, and

wherein the threshold value is based on at least one of (i) the DCI or (ii) the parameters related to omission of the CSI.

2. The method of claim 1 , wherein the some or all of the second part is omitted until the threshold value and the coding rate of the second part of the CSI are the same as each other.

3. The method of claim 1 , wherein the subband CSI included in the second part of the CSI is constituted by a plurality of subbands,

wherein subbands in the plurality of subbands are omitted based on a priority of each of the plurality of subbands, and

wherein the some or all of the second part is omitted without omitting the first part of the CSI.

4. The method of claim 3 , wherein the subbands in the plurality of subbands are omitted according to an order of lower priority.

5. The method of claim 4 , wherein the DCI includes at least one of pattern information, omission rate information, or specific subband information related with an omitted subband among the plurality of subbands constituting the second part.

6. The method of claim 5 , wherein the pattern information includes an offset value and a Comb value representing a pattern of the omitted subband.

7. The method of claim 1 , wherein the first part includes a rank indicator (RI), a channel quality indicator (CQI), and an indicator indicating a number of beams having an amplitude other than 0, and

wherein the second part includes a precoding matrix indicator (PMI).

8. The method of claim 1 , further comprising:

transmitting, to the base station, additional information for restoring subband precoding matrix indicator(PMI)s corresponding to the omitted some of the second part of the CSI,

wherein the subband PMIs corresponding to the omitted some of the second part of the CST is restored based on the additional information and reported subband PMTs corresponding to reported some of the second part of the CSI other than the omitted some of the second part of the CSI.

9. The method of claim 1 , wherein an entirety of the first part is transmitted before the second part is transmitted.

10. The method of claim 1 , wherein the first part includes a rank indicator (RI) and a channel quality indicator (CQI), and

wherein the second part includes a precoding matrix indicator (PMI).

11. A method of receiving, by a base station, channel state information (CSI) from a user equipment in a wireless communication system, the method comprising:

transmitting configuration information related with reporting of the CSI to the user equipment,

wherein the configuration information includes parameters related to omission of the CSI, and

wherein the CSI comprises (i) a first part used to identify a number of information bits of a second part of the CSI and (ii) the second part;

transmitting downlink control information (DCI) including information regarding a coding rate of the CSI to the user equipment;

transmitting a first reference signal for measuring a channel to the user equipment; and

receiving the CSI of the measured channel through a physical uplink shared channel (PUSCH) from the user equipment,

wherein the second part of the CSI includes a wideband CSI and a subband CSI,

wherein the wideband CSI included in the second part of the CSI has a higher priority than the subband CSI included in the second part of the CSI,

wherein some or all of the second part of the CSI is omitted based on a coding rate of the second part being greater than a threshold value, and

wherein the threshold value is based on at least one of (i) the DCI or (ii) the parameters related to omission of the CSI.

12. The method of claim 11 , wherein the some or all of the second part is omitted until the threshold value and the coding rate of the second part of the CSI are the same as each other.

13. The method of claim 11 , wherein the second part is constituted by a plurality of subbands,

wherein subbands in the plurality of subbands are omitted based on a priority of each of the plurality of subbands, and

wherein the some or all of the second part is omitted without omitting the first part of the CSI.

14. The method of claim 13 , wherein the subbands in the plurality of subbands are omitted according to an order of lower priority.

15. The method of claim 14 , wherein the DCI includes at least one of pattern information, omission rate information, or specific subband information related with an omitted subband among the plurality of subbands constituting the second part.

16. The method of claim 15 , wherein the pattern information includes an offset value and a Comb value representing a pattern of the omitted subband.

17. The method of claim 11 , wherein the first part includes a rank indicator (RI) and a channel quality indicator (CQI), and

wherein the second part includes a precoding matrix indicator (PMI).

18. The method of claim 11 , further comprising:

receiving, from the user equipment, additional information for restoring subband precoding matrix indicator(PMI)s corresponding to the omitted some of the second part of the CSI,

wherein the subband PMIs corresponding to the omitted some of the second part of the CSI is restored based on the additional information and reported subband PMIs corresponding to reported some of the second part of the CSI other than the omitted some of the second part of the CSI.

19. The method of claim 11 , wherein an entirety of the first part is transmitted before the second part is transmitted.

20. A user equipment configured to report channel state information (CSI) in a wireless communication system, the user equipment comprising:

a radio frequency (RF) module;

at least one processor; and

at least one computer memory operably connectable to the at least one processor and storing instructions that, when executed by the at least one processor, perform operations comprising:

receiving configuration information related to reporting of the CSI from a base station,

wherein the configuration information includes parameters related to omission of the CSI, and

wherein the CSI comprises (i) a first part used to identify a number of information bits of a second part of the CSI and (ii) the second part;

receiving downlink control information (DCI) including information regarding a coding rate of the CSI from the base station;

receiving a first reference signal for channel measurement;

measuring a channel based on the first reference signal; and

reporting the CSI of the measured channel to the base station through a physical uplink shared channel (PUSCH),

wherein the second part of the CSI includes a wideband CSI and a subband CSI,

wherein the wideband CSI included in the second part of the CSI has a higher priority than the subband CSI included in the second part of the CSI,

wherein some or all of the second part of the CSI is omitted based on a coding rate of the second part being greater than a threshold value, and

wherein the threshold value is based on at least one of (i) the DCI or (ii) the parameters related to omission of the CSI.