Method for reporting channel state information in wireless communication system and apparatus therefor
Provided are a method and an apparatus for reporting channel state information (CSI) by a user equipment in a wireless communication system. According to the present invention, the user equipment may receive configuration information related with the CSI from a base station and measure the CSI based on the configuration information. Thereafter, the user equipment includes reporting the CSI to the base station and the CSI includes a rank indicator (RI), a channel quality indicator (CQI), and an indicator indicating the number of amplitude coefficients other than 0 and the second part includes a precoding matrix indicator (PMI).
1. A method of reporting, by a user equipment (UE), channel state information (CSI) in a wireless communication system, the method comprising:
receiving, from a base station (BS), configuration information related with the CSI;
measuring the CSI based on the configuration information; and
reporting, to the BS, the CSI,
wherein based on the CSI classified as Type I CSI:
the Type I CSI comprises a first part and a second part,
the first part of the Type I CSI 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 Type I CSI includes a precoding matrix indicator (PMI), and a second CQI for a second codeword, and
wherein based on the CSI classified as Type II CSI:
the Type II CSI comprises a first part and a second part,
the first part of the Type II CSI includes the rank indicator (RI), a CQI, and an indicator indicating a number of amplitude coefficients other than 0, and
the second part of the Type II CSI includes a precoding matrix indicator (PMI),
wherein the number of bits of the indicator indicating the number of amplitude coefficients other than 0 is configured for each layer based on the following equation, [log 2 2L−1], and
wherein L denotes a number of base vectors linearly combined by a linear combination based codebook.
2. The method of claim 1 , wherein a payload size of the second part is determined 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 indicating the number of amplitude coefficients other than 0.
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 number of bits of the first part increases.
5. The method of claim 1 , wherein the RI, the CQI, and the indicator indicating the number of amplitude coefficients other than 0 are each encoded through a same coding rate with separate field in the first part.
6. The method of claim 1 , wherein the indicator indicating the number of amplitude coefficients other than 0 is independently indicated 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 number of bits of the first part and the number of bits 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 channel state information (CSI) 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;
measure the CSI based on the configuration information; and
report, to the BS, the CSI,
wherein based on the CSI classified as Type I CSI:
the Type I CSI comprises a first part and a second part,
the first part of the Type I CSI 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 Type I CSI includes a precoding matrix indicator (PMI), and a second CQI for a second codeword, and
wherein based on the CSI classified as Type II CSI:
the Type II CSI comprises a first part and a second part,
the first part of the Type II CSI includes the rank indicator (RI), a CQI, and an indicator indicating a number of amplitude coefficients other than 0, and
the second part of the Type II CSI includes a precoding matrix indicator (PMI),
wherein the number of bits of the indicator indicating the number of amplitude coefficients other than 0 is configured for each layer based on the following equation, [log 2 2L−1], and
wherein L denotes a number of base vectors linearly combined by a linear combination based codebook.
13. A method of receiving, by a base station (BS), channel state information (CSI) in a wireless communication system, the method comprising:
transmitting, to a user equipment (UE), configuration information related with the CSI; and
receiving, from the UE, the CSI,
wherein based on the CSI classified as Type I CSI:
the Type I CSI comprises a first part and a second part,
the first part of the Type I CSI 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 Type I CSI includes a precoding matrix indicator (PMI), and a second CQI for a second codeword, and
wherein based on the CSI classified as Type II CSI:
the Type II CSI comprises a first part and a second part,
the first part of the Type II CSI includes the rank indicator (RI), a CQI, and an indicator indicating a number of amplitude coefficients other than 0, and
the second part of the Type II CSI includes a precoding matrix indicator (PMI),
wherein the number of bits of the indicator indicating the number of amplitude coefficients other than 0 is configured for each layer based on the following equation, [log 2 2L−1], and
wherein L denotes a number of base vectors linearly combined by a linear combination based codebook.
14. The method of claim 13 , wherein a payload size of the second part is determined by the first part.
15. The method of claim 14 , wherein a bitwidth of the PMI is determined based on the RI and the indicator indicating the number of amplitude coefficients other than 0.
16. The method of claim 13 , wherein the CSI is transmitted on a physical uplink shared channel (PUSCH), and
wherein transmission power of the CSI increases as the number of bits of the first part increases.
17. The method of claim 13 , wherein the RI, the CQI, and the indicator indicating the number of amplitude coefficients other than 0 are each encoded through a same coding rate with separate field in the first part.
18. The method of claim 13 , wherein the indicator indicating the number of amplitude coefficients other than 0 is independently indicated for each layer.
19. The method of claim 13 ,
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.
20. The method of claim 19 , 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.
21. The method of claim 13 , wherein the number of symbols to which the first part is mapped is determined based on the number of bits of the first part and the number of bits of the second part.
22. The method of claim 13 , wherein the first part and the second part are each separately encoded.
23. The method of claim 13 ,
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.
24. A base station (BS) for receiving channel state information (CSI) 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; and
receive, from the UE, the CSI,
wherein based on the CSI classified as Type I CSI:
the Type I CSI comprises a first part and a second part,
the first part of the Type I CSI 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 Type I CSI includes a precoding matrix indicator (PMI), and a second CQI for a second codeword, and
wherein based on the CSI classified as Type II CSI:
the Type II CSI comprises a first part and a second part,
the first part of the Type II CSI includes the rank indicator (RI), a CQI, and an indicator indicating a number of amplitude coefficients other than 0, and
the second part of the Type II CSI includes a precoding matrix indicator (PMI),
wherein the number of bits of the indicator indicating the number of amplitude coefficients other than 0 is configured for each layer based on the following equation, [log 2 2L−1], and
wherein L denotes a number of base vectors linearly combined by a linear combination based codebook.