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

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

receiving, from a base station (BS), configuration information related with the CSI report;

calculating at least one CSI parameter based on the configuration information; and

reporting, to the BS, the CSI report including the at least one CSI parameter,

wherein the CSI report is (a) one of (i) Type I CSI feedback and (ii) Type II CSI feedback and (b) comprises two parts including a first part and a second part,

wherein based on the CSI report being the Type I CSI feedback:

the first part of the CSI report includes a rank indicator (RI), a CSI-RS resource indicator (CRI), and a first channel quality indicator (CQI) for a first codeword, and

the second part of the CSI report includes a precoding matrix indicator (PMI), and a second CQI for a second codeword, and

wherein based on the CSI report being the Type II CSI feedback:

the first part of the CSI report includes the rank indicator (RI), a CQI, and an indicator for a number of non-zero wideband amplitude coefficients per layer, and

the second part of the CSI report includes a precoding matrix indicator (PMI),

wherein a bitwidth of the indicator for the number of non-zero amplitude coefficients is configured for each layer based on the following equation, ┌log 2 2L−1┐,

wherein L is number of beams, and

wherein L vectors are combined by a codebook.

2. The method of claim 1 , wherein a payload size of the second part is identified by the first part.

3. The method of claim 2 , wherein a bitwidth of the PMI is determined based on the RI and the indicator for the number of non-zero amplitude coefficients.

4. The method of claim 1 , wherein the CSI is transmitted on a physical uplink shared channel (PUSCH), and

wherein transmission power of the CSI increases as the bitwidth of the first part increases.

5. The method of claim 1 , wherein the RI, the CQI, and the indicator for the number of non-zero amplitude coefficients are each encoded through a same coding rate with separate field in the first part.

6. The method of claim 1 , wherein the indicator for the number of non-zero amplitude coefficients is independently configured for each layer.

7. The method of claim 1 ,

wherein the first part has a higher CSI priority than the second part, and

wherein the first part and the second part are mapped to a symbol next a symbol to which a demodulation reference signal (DMRS) is mapped according to the CSI priority.

8. The method of claim 7 , wherein the first part and the second part are sequentially mapped in a direction in which an index of the symbol to which the DMRS is mapped increases.

9. The method of claim 1 , wherein the number of symbols to which the first part is mapped is determined based on the bitwidth of the first part and the bitwidth of the second part.

10. The method of claim 1 , wherein the first part and the second part are each separately encoded.

11. The method of claim 1 ,

wherein the first part and the second part are transmitted through different transmission powers, and

wherein specific values of the first part and/or the second part are/is repeatedly transmitted.

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

one or more transceivers transmitting and receiving a radio signal; and

one or more processors controlling the one or more transceivers,

wherein the one or more processors are configured to:

receive, from a base station (BS), configuration information related with the CSI report;

calculate at least one CSI parameter based on the configuration information; and

report, to the BS, the CSI report including the at least one CSI parameter,

wherein the CSI report is (a) one of (i) Type I CSI feedback and (ii) Type II CSI feedback and (b) comprises two parts including a first part and a second part,

wherein based on the CSI report being the Type I CSI feedback:

the first part of the CSI report includes a rank indicator (RI), a CSI-RS resource indicator (CRI), and a first channel quality indicator (CQI) for a first codeword, and

the second part of the CSI report includes a precoding matrix indicator (PMI), and a second CQI for a second codeword, and

wherein based on the CSI report being the Type II CSI feedback:

the first part of the CSI report includes the rank indicator (RI), a CQI, and an indicator for a number of non-zero wideband amplitude coefficients per layer, and

the second part of the CSI report includes a precoding matrix indicator (PMI),

wherein a bitwidth of the indicator for the number of non-zero amplitude coefficients is configured for each layer based on the following equation, ┌log 2 2L−1┐, and

wherein L denotes a number of vectors combined by a codebook.

13. A method of receiving, by a base station (BS), a channel state information (CSI) report in a wireless communication system, the method comprising:

transmitting, to a user equipment(UE), configuration information related with the CSI report;

receiving, from the UE, the CSI report,

wherein the CSI report is (a) one of (i) Type I CSI feedback and (ii) Type II CSI feedback and (b) comprises two parts including a first part and a second part,

wherein based on the CSI report being the Type I CSI feedback:

the first part of the CSI report includes a rank indicator (RI), a CSI-RS resource indicator (CRI), and a first channel quality indicator (CQI) for a first codeword, and

the second part of the CSI report includes a precoding matrix indicator (PMI), and a second CQI for a second codeword, and

wherein based on the CSI report being the Type II CSI feedback:

the first part of the CSI report includes the rank indicator (RI), a CQI, and an indicator for a number of non-zero wideband amplitude coefficients per layer, and

the second part of the CSI report includes a precoding matrix indicator (PMI),

wherein a bitwidth of the indicator for the number of non-zero amplitude coefficients is configured for each layer based on the following equation, ┌log 2 2L−1┐,

wherein L is number of beams, and

wherein L vectors are combined by a codebook.

14. A base station (BS) for receiving a channel state information (CSI) report in a wireless communication system, the BS comprising:

one or more transceivers transmitting and receiving a radio signal; and

one or more processors controlling the one or more transceivers,

wherein the one or more processors are configured to:

transmit, to a user equipment(UE), configuration information related with the CSI report;

receive, from the UE, the CSI report,

wherein the CSI report is (a) one of (i) Type I CSI feedback and (ii) Type II CSI feedback and (b) comprises two parts including a first part and a second part,

wherein based on the CSI report being the Type I CSI feedback:

the first part of the CSI report includes a rank indicator (RI), a CSI-RS resource indicator (CRI), and a first channel quality indicator (CQI) for a first codeword, and

the second part of the CSI report includes a precoding matrix indicator (PMI), and a second CQI for a second codeword, and

wherein based on the CSI report being the Type II CSI feedback:

the first part of the CSI report includes the rank indicator (RI), a CQI, and an indicator for a number of non-zero wideband amplitude coefficients per layer, and

the second part of the CSI report includes a precoding matrix indicator (PMI),

wherein a bitwidth of the indicator for the number of non-zero amplitude coefficients is configured for each layer based on the following equation, ┌log 2 2L−1┐,

wherein L is number of beams, and

wherein L vectors are combined by a codebook.