# US 2021/0242914 A1 · Method and apparatus for reporting channel state information in wireless communication system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0242914 A1 - Document ID: US20210242914A1 - Status: Published application - Kind: A1 - Application number: 17/263,510 - Filed: 2019-07-29 - Published: 2021-08-05 - Earliest claimed: 2018-07-27 - Assignees: LG Electronics Inc. - Applicants: LG Electronics Inc. - Inventors: Haewook PARK; Hyungtae KIM; Jiwon KANG; Sangrim LEE - Web page: https://patentgrep.com/patent/US20210242914A1 ## CPC - H04B 7/0486: {taking channel rank into account} - H04B 7/063: {Parameters other than those covered in groups H04B7/0623 - H04B7/0634, e.g. channel matrix rank or transmit mode selection} - H04L 5/0048: {Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091)} - H04B 7/0469: {taking special antenna structures, e.g. cross polarized antennas into account} - H04B: TRANSMISSION - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract The present disclosure relates to a method, performed by a user equipment (UE), for reporting channel state information (CSI) in a wireless communication system and an apparatus therefor. According to the present disclosure, the UE receives a channel state information reference signal (CSI-RS) from a base station through a multiple antenna port; and reports the CSI to the base station, wherein the CSI includes a precoding matrix indicator for a codebook generated by linear combination, wherein the codebook is generated based on a specific parameter set, and wherein the specific parameter set is differently set/applied based on at least one of a rank value or at least one layer index of a specific rank. ## Claims ### Claim 1 A method for transmitting channel state information (CSI) by a user equipment (UE) in a wireless communication system, comprising: receiving a channel state information reference signal (CSI-RS) from a base station through a multiple antenna port; and reporting the CSI to the base station, wherein the CSI includes a precoding matrix indicator for a codebook generated by linear combination, wherein the codebook is generated based on a specific parameter set, and wherein the specific parameter set is differently set/applied based on a rank value. ### Claim 2 (depends on 1) The method of claim 1, further comprising: receiving, from the base station, information on the specific parameter set used for generating the codebook through higher layer signaling. ### Claim 3 (depends on 1) The method of claim 1, wherein the specific parameter set for a case where the rank value is 1 and the specific parameter set for a case where the rank value is 2 are identically set/applied. ### Claim 4 (depends on 3) The method of claim 3, wherein the specific parameter set for a case where the rank value is 3 and the specific parameter set for a case where the rank value is 4 are identically set/applied. ### Claim 5 (depends on 1) The method of claim 1, wherein the CSI consists of a first part and a second part, wherein the first part includes a rank indicator (RI), a channel quality indicator (CQI), and an indicator indicating the number of combining coefficients having an amplitude of a positive real value, and wherein the second part includes the PMI. ### Claim 6 (depends on 5) The method of claim 5, wherein the first part has a fixed payload size and is used to identify the number of information bits of the second part. ### Claim 7 (depends on 4) The method of claim 4, wherein the specific parameter set for (i) the case where the rank value is 1 and (ii) the case where the rank value is 2 are differently set/applied with the specific parameter set for (i) the case where the rank value is 3 and (ii) the case where the rank value is 4. ### Claim 8 (depends on 1) The method of claim 1, wherein the specific parameter set is identically set/applied to each layer. ### Claim 9 A method for receiving channel state information (CSI) by a base station in a wireless communication system, comprising: transmitting a channel state information reference signal (CSI-RS) to a terminal through a multi-antenna port; and receiving CSI from the terminal, wherein the CSI includes a precoding matrix indicator for a codebook generated by linear combination, wherein the codebook is generated based on a specific parameter set, and wherein the specific parameter set is differently set/applied based on a rank value. ### Claim 10 A user equipment (UE) for transmitting channel state information (CSI) in a wireless communication system, the UE comprising: RF (Radio Frequency) module for transmitting and receiving a radio signal; and a processor for controlling the RF module, wherein the processor, receiving a channel state information reference signal (CSI-RS) from a base station through a multiple antenna port; and reporting the CSI to the base station, wherein the CSI includes a precoding matrix indicator for a codebook generated by linear combination, wherein the codebook is generated based on a specific parameter set, and wherein the specific parameter set is differently set/applied based on a rank value. ### Claim 11 (depends on 10) The UE of claim 10, wherein the processor, receiving, from the base station, information on the specific parameter set used for generating the codebook through higher layer signaling. ### Claim 12 (depends on 10) The UE of claim 10, wherein the specific parameter set for a case where the rank value is 1 and the specific parameter set for a case where the rank value is 2 are identically set/applied. ### Claim 13 (depends on 12) The UE of claim 12, wherein the specific parameter set for a case where the rank value is 3 and the specific parameter set for a case where the rank value is 4 are identically set/applied. ### Claim 14 (depends on 10) The UE of claim 10, wherein the CSI consists of a first part and a second part, wherein the first part includes a rank indicator (RI), a channel quality indicator (CQI), and an indicator indicating the number of combining coefficients having an amplitude of a positive real value, and wherein the second part includes the PMI. ### Claim 15 (depends on 14) The UE of claim 14, wherein the first part has a fixed payload size and is used to identify the number of information bits of the second part. ### Claim 16 (depends on 13) The UE of claim 13, wherein the specific parameter set for (i) the case where the rank value is 1 and (ii) the case where the rank value is 2 are differently set/applied with the specific parameter set for (i) the case where the rank value is 3 and (ii) the case where the rank value is 4. ### Claim 17 (depends on 10) The UE of claim 10, wherein the specific parameter set is identically set/applied to each layer.