# US 12,763,839 B2 · Method and apparatus for codebook subset restriction > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,763,839 B2 - Document ID: US12763839B2 - Status: Granted - Kind: B2 - Application number: 18/448,059 - Filed: 2023-08-10 - Published: 2024-02-15 - Granted: 2026-10-13 - Earliest claimed: 2022-08-12 - Assignees: Samsung Electronics Co., Ltd. - Applicants: Samsung Electronics Co., Ltd. - Inventors: Ameha Tsegaye Abebe; Younsun Kim; Seongmok Lim; Youngrok Jang; Kyungjun Choi - Web page: https://patentgrep.com/patent/US12763839B2 ## CPC - H04B 7/0663: {using vector or matrix manipulations} - H04B 7/0626: {Channel coefficients, e.g. channel state information [CSI]} - H04B 7/0639: {Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection} - H04L 5/0053: {Allocation of signalling, i.e. of overhead other than pilot signals} - H04B: TRANSMISSION - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A method performed by a UE in a wireless communication system includes receiving configuration information on a CSI report including information on a codebook subset restriction, the codebook subset restriction being configured to each TRP of a plurality of TRPs performing coherent joint transmission or to a subset of the plurality of TRPs based on the information, measuring CSI based on at least one CSI-RS resource, and transmitting the CSI based on the codebook subset restriction. ## Claims ### Claim 1 A method performed by a user equipment (UE) in a wireless communication system, the method comprising: receiving configuration information for a channel state information (CSI) report including information on a codebook subset restriction for coherent joint transmission (CJT) CSI; measuring CSI based on CSI-RS resources corresponding to a plurality of transmission reception points (TRPs) performing CJT; and transmitting the CSI based on the information on the codebook subset restriction, wherein the information on the codebook subset restriction for the CJT CSI comprises a plurality of bit sequences, each bit sequence corresponding to one of the plurality of TRPs, wherein whether the codebook subset restriction is applied to each TRP is determined based on one of the plurality of bit sequences corresponding to each TRP, and wherein each bit sequence is formed by concatenating a first bit sequence indicating vector groups of each TRP to which the codebook subset restriction is applied and a second bit sequence indicating a maximum average coefficient amplitude corresponding to the vector groups. ### Claim 2 (depends on 1) The method of claim 1, wherein the information on the codebook subset restriction for the CJT CSI includes restriction information associated with amplitude coefficients for the plurality of TRPs, and wherein the restriction information comprises a bit sequence indicating a maximum amplitude coefficient calculated based on an average value of maximum amplitude coefficients across the plurality of TRPs. ### Claim 3 (depends on 1) The method of claim 1, wherein the configuration information further includes information on a codebook subset restriction for time-correlated CSI, the time-correlated CSI being compressed either in a time domain or a Doppler domain, and wherein a maximum amplitude coefficient indicated by the information on the codebook subset restriction for time-correlated CSI is calculated based on an average value of maximum amplitude coefficients across basis vectors of the time domain or the Doppler domain. ### Claim 4 (depends on 1) The method of claim 1, wherein a number N of the plurality of bit sequences is identical to a number of the plurality of TRPs, and wherein r-th bit sequence of the plurality of bit sequences is for r-th TRP of the plurality of TRPs, where r∈{1, . . . , N}. ### Claim 5 A method performed by a base station in a wireless communication system, the method comprising: transmitting, to a user equipment (UE), configuration information for a channel state information (CSI) report including information on a codebook subset restriction for coherent joint transmission (CJT) CSI; transmitting, to the UE, a CSI-RS on CSI-RS resources corresponding to a plurality of transmission reception points (TRPs) performing CJT; and receiving, from the UE, CSI based on the information on the codebook subset restriction, wherein the CSI is derived based on the CSI-RS resources, wherein the information on the codebook subset restriction for the CJT CSI comprises a plurality of bit sequences, each bit sequence corresponding to one of the plurality of TRPs, wherein whether the codebook subset restriction is applied to each TRP is determined based on one of the plurality of bit sequences corresponding to each TRP, and wherein each bit sequence is formed by concatenating a first bit sequence indicating vector groups of each TRP to which the codebook subset restriction is applied and a second bit sequence indicating a maximum average coefficient amplitude corresponding to the vector groups. ### Claim 6 (depends on 5) The method of claim 5, wherein the information on the codebook subset restriction for the CJT CSI includes restriction information associated with amplitude coefficients for the plurality of TRPs, and wherein the restriction information comprises a bit sequence indicating a maximum amplitude coefficient calculated based on an average value of maximum amplitude coefficients across the plurality of TRPs. ### Claim 7 (depends on 5) The method of claim 5, wherein the configuration information further includes information on a codebook subset restriction for time-correlated CSI, the time-correlated CSI being compressed either in a time domain or a Doppler domain, and wherein a maximum amplitude coefficient indicated by the information on the codebook subset restriction for time-correlated CSI is calculated based on an average value of maximum amplitude coefficients across basis vectors of the time domain or the Doppler domain. ### Claim 8 A user equipment (UE) in a wireless communication system, the UE comprising: a transceiver; and a controller coupled with the transceiver and configured to: receive configuration information for a channel state information (CSI) report including information on a codebook subset restriction for coherent joint transmission (CJT) CSI, measure CSI based on CSI-RS resources corresponding to a plurality of transmission reception points (TRPs) performing CJT, and transmit the CSI based on the information on the codebook subset restriction, wherein the information on the codebook subset restriction for the CJT CSI comprises a plurality of bit sequences, each bit sequence corresponding to one of the plurality of TRPs, wherein whether the codebook subset restriction is applied to each TRP is determined based on one of the plurality of bit sequences corresponding to each TRP, and wherein each bit sequence is formed by concatenating a first bit sequence indicating vector groups of each TRP to which the codebook subset restriction is applied and a second bit sequence indicating a maximum average coefficient amplitude corresponding to the vector groups. ### Claim 9 (depends on 8) The UE of claim 8, wherein the information on the codebook subset restriction for the CJT CSI includes restriction information associated with amplitude coefficients for the plurality of TRPs, and wherein the restriction information comprises a bit sequence indicating a maximum amplitude coefficient calculated based on an average value of maximum amplitude coefficients across the plurality of TRPs. ### Claim 10 (depends on 8) The UE of claim 8, wherein the configuration information further includes information on a codebook subset restriction for time-correlated CSI, the time-correlated CSI being compressed either in a time domain or a Doppler domain, and wherein a maximum amplitude coefficient indicated by the information on the codebook subset restriction for time-correlated CSI is calculated based on an average value of maximum amplitude coefficients across basis vectors of the time domain or the Doppler domain. ### Claim 11 A base station in a wireless communication system, the base station comprising: a transceiver; and a controller coupled with the transceiver and configured to: transmit, to a user equipment (UE), configuration information for a channel state information (CSI) report including information on a codebook subset restriction for coherent joint transmission (CJT) CSI, transmit, to the UE, a CSI-RS on CSI-RS resources corresponding to a plurality of transmission reception points (TRPs) performing CJT, and receive, from the UE, CSI based on the information on the codebook subset restriction, wherein the CSI is derived based on the CSI-RS resources, wherein the information on the codebook subset restriction for the CJT CSI comprises a plurality of bit sequences, each bit sequence corresponding to one of the plurality of TRPs, wherein whether the codebook subset restriction is applied to each TRP is determined based on one of the plurality of bit sequences corresponding to each TRP, and wherein each bit sequence is formed by concatenating a first bit sequence indicating vector groups of each TRP to which the codebook subset restriction is applied and a second bit sequence indicating a maximum average coefficient amplitude corresponding to the vector groups. ### Claim 12 (depends on 11) The base station of claim 11, wherein the information on the codebook subset restriction for the CJT CSI includes restriction information associated with amplitude coefficients for the plurality of TRPs, and wherein the restriction information comprises a bit sequence indicating a maximum amplitude coefficient calculated based on an average value of maximum amplitude coefficients across the plurality of TRPs.