# US 10,374,678 B2 · Channel state information feedback method and apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,374,678 B2 - Document ID: US10374678B2 - Status: Granted - Kind: B2 - Application number: 15/752,106 - Filed: 2016-08-12 - Published: 2018-08-23 - Granted: 2019-08-06 - Earliest claimed: 2015-08-13 - Assignees: Samsung Electronics Co., Ltd. - Applicants: Samsung Electronics Co., Ltd. - Inventors: Keon-Kook Lee; Young-Han Nam; Tae-Young Kim; Jee-Hwan Noh; Hyun-Il Yoo; Su-Ryong Jeong - Web page: https://patentgrep.com/patent/US10374678B2 ## CPC - H04B 7/0626: {Channel coefficients, e.g. channel state information [CSI]} - H04B 7/0417: Feedback systems - H04B 7/06: at the transmitting station - H04B 7/0617: {for beam forming} - H04B 7/063: {Parameters other than those covered in groups H04B7/0623 - H04B7/0634, e.g. channel matrix rank or transmit mode selection} - H04B 7/0632: {Channel quality parameters, e.g. channel quality indicator [CQI]} - 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 7/0413: MIMO systems - H04L 5/005: {of common pilots, i.e. pilots destined for multiple users or terminals} - 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 5G or pre-5G communication system for supporting a higher data transfer rate beyond a 4G communication system such as LTE. A method and an apparatus for transmitting and receiving channel state information are disclosed. The method comprises: a step of transmitting, to a terminal, a signaling message including first information indicating at least one precoding matrix which is applicable to a symbol vector to be transmitted; a step of transmitting, to the terminal, a channel status information-reference signal (CSI-RS) for the terminal; and a step of receiving channel state information including a channel quality indicator (CQI) which is calculated using the selected precoding matrix on the basis of second information from the terminal. ## Claims ### Claim 1 A method for receiving channel state information, the method comprising: transmitting, to a user equipment (UE), a signaling message comprising information indicating whether the UE is configured without a precoding matrix indicator (PMI) reporting or not; transmitting, to the UE, a channel status information-reference signal (CSI-RS) for the UE; and receiving channel state information comprising a channel quality indicator (CQI) that is calculated based on a codebook which is provided to the UE through a higher-layer signaling, if the information indicates that the UE is configured without the PMI reporting, wherein the codebook is based on a number of layers and a number of ports used for CSI reporting. ### Claim 2 (depends on 1) The method of claim 1, wherein the channel state information comprises a rank indicator and the CQI without a precoding matrix indicator. ### Claim 3 (depends on 1) The method of claim 1, wherein the CSI-RS is beamformed based on an uplink signal received from the UE. ### Claim 4 (depends on 1) The method of claim 1, wherein the CQI included in the channel state information is calculated based on a precoding matrix selected for each rank by a codebook subset restriction function and a unitary matrix of the selected precoding matrix. ### Claim 5 A method for transmitting channel state information, the method comprising: receiving, from an evolved node B (eNB), a signaling message comprising information indicating whether a user equipment (UE) is configured without a precoding matrix indicator (PMI) reporting or not; receiving, from the eNB, a channel status information-reference signal (CSI-RS) for the UE; and transmitting, to the eNB, channel state information comprising a channel quality indicator (CQI) that is calculated based on a codebook which is provided to the UE through a higher-layer signaling, if the information indicates that the UE is configured without the PMI reporting, wherein the codebook is based on a number of layers and a number of ports used for CSI reporting. ### Claim 6 (depends on 5) The method of claim 5, wherein the channel state information comprises a rank indicator and the CQI without a precoding matrix indicator. ### Claim 7 (depends on 5) The method of claim 5, wherein the CSI-RS is beamformed based on an uplink signal received from the UE. ### Claim 8 (depends on 5) The method of claim 5, wherein the CQI included in the channel state information is calculated based on a precoding matrix selected for each rank by a codebook subset restriction function of the eNB and a unitary matrix of the selected precoding matrix. ### Claim 9 An apparatus in an evolved node B (eNB) for receiving channel state information, the apparatus comprising: a controller configured to: transmit, to a user equipment (UE), a signaling message comprising information indicating whether the UE is configured without a precoding matrix indicator (PMI) reporting or not, transmit, to the UE, a channel status information-reference signal (CSI-RS) for the UE, and receive channel state information comprising a channel quality indicator (CQI) that is calculated based on a codebook which is provided to the UE through a higher-layer signaling, if the information indicates that the UE is configured without the PMI reporting, wherein the codebook is based on a number of layers and a number of ports used for CSI reporting; and a transceiver configured to receive, from the UE, the channel state information under control of the controller. ### Claim 10 (depends on 9) The apparatus of claim 9, wherein the channel state information comprises a rank indicator and the CQI without a precoding matrix indicator. ### Claim 11 (depends on 9) The apparatus of claim 9, wherein the CSI-RS is beamformed based on an uplink signal received from the UE. ### Claim 12 (depends on 9) The apparatus of claim 9, wherein the CQI included in the channel state information is calculated based on a precoding matrix selected for each rank by a codebook subset restriction function and a unitary matrix of the selected precoding matrix. ### Claim 13 An apparatus in a user equipment (UE) for transmitting channel state information, the apparatus comprising: a controller configured to: receive, from an evolved node B (eNB), a signaling message comprising information indicating whether the UE is configured without a precoding matrix indicator (PMI) reporting or not, receive, from the eNB, a channel status information-reference signal (CSI-RS) for the UE, and transmit, to the eNB, channel state information comprising a channel quality indicator (CQI) that is calculated based on a codebook which is provided to the UE through a higher-layer signaling, if the information indicates that the UE is configured without the PMI reporting, wherein the codebook is based on a number of layers and a number of ports used for CSI reporting; and a transceiver configured to: transmit, to the eNB, the channel state information under control of the controller.