# US 12,003,994 B2 · CSI reporting > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,003,994 B2 - Document ID: US12003994B2 - Status: Granted - Kind: B2 - Application number: 17/306,774 - Filed: 2021-05-03 - Published: 2021-08-19 - Granted: 2024-06-04 - Earliest claimed: 2011-01-11 - Assignees: Texas Instruments Incorporated - Applicants: Texas Instruments Incorporated - Inventors: Vikram Chandrasekhar; Runhua Chen; Anthony Edet Ekpenyong - Web page: https://patentgrep.com/patent/US12003994B2 ## CPC - H04W 24/10: Scheduling measurement reports {; Arrangements for measurement reports} - H04B 7/0632: {Channel quality parameters, e.g. channel quality indicator [CQI]} - H04L 5/0057: {Physical resource allocation for CQI} - H04W 74/0841: {with collision treatment} - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04B: TRANSMISSION - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A method and user equipment for channel state information (CSI) reporting are described. The method receives a channel quality indicator request. The method determines a channel quality indicator based on a CSI reference resource. The method transmits a CSI report that includes the channel quality indicator via a Physical Uplink Control CHannel (PUCCH) on an uplink subframe. The CSI reference resource belongs to a subframe subset for which the CSI report is sent. The CSI reference resource includes overhead of Demodulation Reference Signals according to a corresponding rank report. ## Claims ### Claim 1 A method comprising: receiving a channel quality indicator request; determining a channel quality indicator based on a channel state information (CSI) reference resource; and transmitting a CSI report that includes the channel quality indicator via a Physical Uplink Control CHannel (PUCCH) on an uplink subframe, wherein the CSI reference resource belongs to a subframe subset for which the CSI report is sent, and wherein the CSI reference resource includes overhead of Demodulation Reference Signals according to a corresponding rank report. ### Claim 2 (depends on 1) The method of claim 1, wherein: a step of transmitting a channel quality indicator request is periodic with each transmission occurring on a subframe having a smallest value nCQI_ref greater than or equal to 4 that corresponds to a valid downlink subframe. ### Claim 3 (depends on 2) The method of claim 2, wherein: a valid downlink subframe is a subframe configured as a downlink subframe at a user equipment. ### Claim 4 (depends on 2) The method of claim 2, wherein: a valid downlink subframe is not a Multimedia Broadcast multicast service Single Frequency Network subframe. ### Claim 5 (depends on 2) The method of claim 2, further comprising: not transmitting a channel quality indicator request if there is no valid downlink subframe. ### Claim 6 (depends on 1) The method of claim 1, wherein: a step of transmitting a channel quality indicator request is aperiodic with each transmission occurring on a same subframe as a corresponding channel quality indicator request in an uplink Downlink Control Information format. ### Claim 7 (depends on 1) The method of claim 1, wherein: a step of transmitting a channel quality indicator request is aperiodic with each transmission occurring on a next valid downlink subframe following the channel quality indicator request that is a Random Access Response Grant subframe. ### Claim 8 (depends on 1) The method of claim 1, wherein: a user equipment is configured in transmission mode 9. ### Claim 9 (depends on 1) The method of claim 1, wherein: if a channel quality indicator reference index is a Cell-specific Channel State Information Reference Signal subframe the user equipment assumes the presence of Cell-specific Channel State Information Reference Signals in determining a channel quality indicator index. ### Claim 10 (depends on 1) The method of claim 1, wherein: each radio frame is divided into a first set of subframes and a second set of subframes; a step of transmitting a channel quality indicator request is periodic with a first periodicity for transmissions in said first set of subframes and a second periodicity for transmissions in said second set of subframes. ### Claim 11 (depends on 10) The method of claim 10, wherein: a channel quality indicator reference index must be a Cell-specific Channel State Information Reference Signal subframe; and if said first periodicity and said second periodicity causes conflict in transmitting a channel quality indicator response from a user equipment, the user equipment selects for periodic Channel State Information reporting a most recent valid Cell-specific Channel State Information Reference Signal subframe n−nCQI_ref, nCQI_ref≥4 which belongs to a subframe subset for which Channel State Information report is sent at n. ### Claim 12 (depends on 10) The method of claim 10, wherein: if said first periodicity and said second periodicity causes conflict in transmitting a channel quality indicator response from a user equipment, the user equipment selects a single Channel State Information reporting configuration of a predetermined offset and a predetermined periodicity. ### Claim 13 (depends on 10) The method of claim 10, wherein: if said first periodicity and said second periodicity causes conflict in transmitting a channel quality indicator response from a user equipment, the user equipment transmits neither channel quality indicator response. ### Claim 14 (depends on 10) The method of claim 10, wherein: if said first periodicity and said second periodicity causes conflict in transmitting a channel quality indicator response from a user equipment, the user equipment transmits both channel quality indicator responses in a same uplink subframe. ### Claim 15 (depends on 10) The method of claim 10, further comprising: transmitting via Radio Resource Control from the base station a predetermined priority between said first set of subframes and said second set of subframes; if said first periodicity and said second periodicity causes conflict in transmitting a channel quality indicator response from a user equipment, the user equipment transmits a response to the channel quality indicator request corresponding to a priority set of subframes. ### Claim 16 (depends on 10) The method of claim 10, wherein: if said first periodicity and said second periodicity causes conflict in transmitting a channel quality indicator response from a user equipment, the user equipment transmits a response to the channel quality indicator request lying closer to n where L = arg ⁢ max l = 1 , 2 ⁢ n CQI_ref , l . ### Claim 17 (depends on 10) The method of claim 10, wherein: if said first periodicity and said second periodicity causes conflict in transmitting a channel quality indicator response from a user equipment, the user equipment transmits a response to the channel quality indicator request lying further from n where L = arg ⁢ max l = 1 , 2 ⁢ n CQI_ref , l . ### Claim 18 A user equipment comprising: a transceiver configured to receive a channel quality indicator request; and a processor configured to determine a channel quality indicator based on a channel state information (CSI) reference resource, wherein the transceiver is configured to transmit a CSI report that includes the channel quality indicator via a Physical Uplink Control CHannel (PUCCH) on an uplink subframe, wherein the CSI reference resource belongs to a subframe subset for which the CSI report is sent, and wherein the CSI reference resource includes overhead of Demodulation Reference Signals according to a corresponding rank report.