# US 10,122,481 B2 · 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 10,122,481 B2 - Document ID: US10122481B2 - Status: Granted - Kind: B2 - Application number: 14/782,561 - Filed: 2014-04-16 - Published: 2016-02-18 - Granted: 2018-11-06 - Earliest claimed: 2013-04-16 - Assignees: LG Electronics Inc. - Applicants: LG Electronics Inc. - Inventors: Inkwon Seo; Seungmin Lee; Hanbyul Seo - Web page: https://patentgrep.com/patent/US10122481B2 ## CPC - H04B 17/382: for resource allocation, admission control or handover - H04B 7/0626: {Channel coefficients, e.g. channel state information [CSI]} - H04L 5/0091: {Signalling for the administration of the divided path, e.g. signalling of configuration information} - H04W 24/10: Scheduling measurement reports {; Arrangements for measurement reports} - H04W 72/20: Control channels or signalling for resource management - H04W 72/23: in the downlink direction of a wireless link, i.e. towards a terminal - H04W 72/53: based on regulatory allocation policies - H04W 72/541: using the level of interference - H04L 5/0057: {Physical resource allocation for CQI} - H04L 5/0073: {Allocation arrangements that take into account other cell interferences} - H04L 5/1469: {using time-sharing} - H04B: TRANSMISSION - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract One embodiment of the present invention provides a method for reporting channel state information (CSI) of a terminal in a wireless communication system, comprising the steps of: receiving a downlink signal comprising an uplink grant; when a CSI request field contained in the downlink signal triggers a CSI report, deriving a CQI value on the basis of a PDSCH transmission block in a CSI reference resource; and carrying out a CSI report including the CQI value in subframe n, wherein the CSI reference resource is the last subframe that is not later than a subframe which is four subframes before subframe n. ## Claims ### Claim 1 A method for performing Channel State Information (CSI) reporting by a User Equipment (UE) in a wireless communication system, the method comprising: receiving a first uplink-downlink (UL-DL) configuration indicating whether each of a plurality of subframes is configured as a UL subframe or a DL subframe; receiving a second UL-DL configuration to reconfigure a UL subframe indicated by the first UL-DL configuration to a DL subframe indicated by the second UL-DL configuration; receiving, by the UE, a downlink signal including a Downlink Control Information (DCI) format including a CSI request field; determining, by the UE, a Channel Quality Indicator (CQI) value based on a Physical Downlink Shared Channel (PDSCH) transport block in a CSI reference resource when the CSI request field triggers CSI reporting; and performing, by the UE, CSI reporting including the CQI value in a subframe n, where n is an arbitrary identifier, wherein the CSI reference resource is a last valid subframe among subframes which precede the subframe n by four subframes, wherein the CSI reference resource is a DL subframe indicated by the first UL-DL configuration, and wherein the DL subframe indicated by the first UL-DL configuration and that is the CSI reference resource is not reconfigured by the second UL-DL configuration. ### Claim 2 (depends on 1) The method according to claim 1, wherein, if two or more subframe sets are configured for the UE, a subframe set related to CSI reporting is indicated by a CSI request field included in the downlink signal. ### Claim 3 (depends on 2) The method according to claim 2, wherein the last subframe is included in the subframe set related to CSI reporting. ### Claim 4 (depends on 3) The method according to claim 3, wherein at least one CSI process is configured for the UE. ### Claim 5 (depends on 4) The method according to claim 4, wherein the CSI process includes a CSI-Reference Signal (CSI-RS) resource for signal measurement and two CSI-Interference Measurement (IM) resources for interference measurement. ### Claim 6 (depends on 2) The method according to claim 2, wherein the CSI reference resource corresponds to a subframe set indicated by the CSI request field. ### Claim 7 (depends on 1) The method according to claim 1, wherein the UE has capabilities of receiving a downlink signal in a subframe different from a subframe used in an uplink-downlink configuration indicated by system information. ### Claim 8 (depends on 2) The method according to claim 2, wherein a relationship between a value of the CSI request field and the two or more subframe sets is indicated by a Radio Resource Control (RRC) signaling. ### Claim 9 (depends on 1) The method according to claim 1, wherein a transmission mode configured for the UE is one of transmission modes 1 to 10. ### Claim 10 (depends on 1) The method according to claim 1, wherein the DCI includes the uplink grant. ### Claim 11 (depends on 1) The method according to claim 1, wherein CSI reporting is transmitted over a Physical Uplink Shared Channel (PUSCH). ### Claim 12 A User Equipment (UE) for which a plurality of Channel State Information (CSI)-Reference Signal (RS) configurations is configured in a wireless communication system, the UE comprising: a reception module; and a processor, wherein the processor is configured to receive a first uplink-downlink (UL-DL) configuration indicating whether each of a plurality of subframes is configured as a UL subframe or a DL subframe, receive a second UL-DL configuration to reconfigure a UL subframe indicated by the first UL-DL configuration to a DL subframe indicated by the second UL-DL configuration, receive a downlink signal including a Downlink Control Information (DCI) format including a CSI request field, determine a Channel Quality Indicator (CQI) value based on a Physical Downlink Shared Channel (PDSCH) transport block in a CSI reference resource when the CSI request field triggers CSI reporting, and perform CSI reporting including the CQI value in a subframe n, where n is an arbitrary identifier, wherein the CSI reference resource is a last valid subframe among subframes which precede the subframe n by four subframes, wherein the CSI reference resource is a DL subframe indicated by the first UL-DL configuration, and wherein the DL subframe indicated by the first UL-DL configuration and that is the CSI reference resource is not reconfigured by the second UL-DL configuration.