# US 12,184,361 B2 · Low overhead channel state information (CSI) feedback for multi-transmission point (TRP) transmission > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,184,361 B2 - Document ID: US12184361B2 - Status: Granted - Kind: B2 - Application number: 17/421,787 - Filed: 2020-01-08 - Published: 2022-03-24 - Granted: 2024-12-31 - Earliest claimed: 2019-01-11 - Assignees: Telefonaktiebolaget LM Ericsson (publ) - Applicants: Telefonaktiebolaget LM Ericsson (publ) - Inventors: Shiwei Gao; Sebastian Faxér; Mattias Frenne; Siva Muruganathan - Web page: https://patentgrep.com/patent/US12184361B2 ## CPC - H04B 7/0417: Feedback systems - H04L 1/0026: {Transmission of channel quality indication} - H04B 7/0486: {taking channel rank into account} - H04B 7/0626: {Channel coefficients, e.g. channel state information [CSI]} - H04B 7/0632: {Channel quality parameters, e.g. channel quality indicator [CQI]} - H04B 7/0639: {Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection} - H04B 7/0658: {Feedback reduction} - 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)} - H04L 5/0035: {Resource allocation in a cooperative multipoint environment} - H04L 5/0057: {Physical resource allocation for CQI} - H04L 5/0091: {Signalling for the administration of the divided path, e.g. signalling of configuration information} - H04B: TRANSMISSION - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract Methods and apparatuses are disclosed for low overhead CSI feedback for multi-trp transmissions. In one embodiment, a method implemented in a wireless device includes receiving a configuration of a channel state information, CSI, report setting for at least K>1 non-zero power channel state information reference signal, NZP CSI-RS, resources for channel measurement and a report quantity configuration, K being an integer; receiving a CSI feedback report request for CSI measurement and feedback based at least in part on the CSI report setting; measuring channels based at least in part on the NZP CSI-RS resources; and sending a channel state information, CSI, feedback report based at least in part on: the channel measurements; and the report quantity configuration; and the CSI feedback report comprising at least one of a first CSI feedback and a second CSI feedback. ## Claims ### Claim 1 A method implemented in a wireless device, the method comprising: receiving a configuration of a channel state information, CSI, report setting for at least K>1 non-zero power channel state information reference signal, NZP CSI-RS, resources for channel measurement and a report quantity configuration, K being an integer; receiving a CSI feedback report request for CSI measurement and feedback based at least in part on the CSI report setting; measuring channels based at least in part on the NZP CSI-RS resources; and sending a channel state information, CSI, feedback report based at least in part on: the channel measurements; and the report quantity configuration; and the CSI feedback report comprising a first CSI feedback and a second CSI feedback. ### Claim 2 (depends on 1) The method of claim 1, wherein the first CSI feedback comprises one CSI associated with each of the K NZP CSI-RS resources. ### Claim 3 (depends on 1) The method of claim 1, wherein the second CSI feedback comprises a CSI for one of non-coherent joint, NC-JT, transmission and Ultra Reliable Low Latency, URLL, transmission. ### Claim 4 (depends on 1) The method of claim 1, wherein the second CSI feedback comprises a first rank indicator and a first precoding matrix indicator associated with a first NZP CSI-RS resource, and a second rank indicator and a second precoding matrix indicator associated with a second NZP CSI-RS resource, and a joint channel quality indicator conditioned on the first and the second rank and precoding matrix indicators. ### Claim 5 (depends on 1) The method of claim 1, wherein the second CSI feedback comprises a first rank indicator and a first layer indicator associated with a first NZP CSI-RS resource, and a second rank indicator and a second layer indicator associated with a second NZP CSI-RS resource, and a joint channel quality indicator conditioned on the first and the second rank and layer indicators. ### Claim 6 (depends on 1) The method of claim 1, wherein the second CSI feedback further comprises identities of the first and the second NZP CSI-RS resources. ### Claim 7 (depends on 1) The method of claim 1, further comprising: determining whether to include the second CSI feedback in the CSI feedback report. ### Claim 8 (depends on 1) The method of claim 1, wherein the CSI feedback report further comprises an indicator indicating whether the second CSI feedback is present in the CSI feedback report. ### Claim 9 A method implemented in a network node, the method comprising: configuring a wireless device with a channel state information, CSI, report setting for at least K>1 non-zero power channel state information reference signal, NZP CSI-RS, resources for channel measurement and a report quantity configuration, K being an integer; sending a CSI feedback report request for CSI measurement and feedback based at least in part on the CSI report setting; and receiving a channel state information, CSI, feedback report, the CSI feedback report based at least in part on the CSI report setting; and the CSI feedback report comprising a first CSI feedback and a second CSI feedback. ### Claim 10 (depends on 9) The method of claim 9, wherein the first CSI feedback comprises one CSI associated with each of the K NZP CSI-RS resources. ### Claim 11 (depends on 9) The method of claim 9, wherein the second CSI feedback comprises a CSI for one of non-coherent joint, NC-JT, transmission and Ultra Reliable Low Latency, URLL, transmission. ### Claim 12 (depends on 9) The method of claim 9, wherein the second CSI feedback comprises a first rank indicator and a first precoding matrix indicator associated with a first NZP CSI-RS resource and a second rank indicator and a second precoding matrix indicator associated with a second NZP CSI-RS resource, and a joint channel quality indicator conditioned on the first and the second rank and precoding matrix indicators. ### Claim 13 (depends on 9) The method of claim 9, wherein the second CSI feedback comprises a first rank indicator and a first layer indicator associated with a first NZP CSI-RS resource, and a second rank indicator and a second layer indicator associated with a second NZP CSI-RS resource, and a joint channel quality indicator conditioned on the first and the second rank and layer indicators. ### Claim 14 (depends on 9) The method of claim 9, wherein the second CSI feedback further comprises identities of the first and the second NZP CSI-RS resources. ### Claim 15 A wireless device configured to communicate with a network node, the wireless device comprising processing circuitry configured to cause the wireless device to: receive a configuration of a channel state information, CSI, report setting for at least K>1 non-zero power channel state information reference signal, NZP CSI-RS, resources for channel measurement and a report quantity configuration, K being an integer; receive a CSI feedback report request for CSI measurement and feedback based at least in part on the CSI report setting; measure channels based at least in part on the NZP CSI-RS resources; and send a channel state information, CSI, feedback report based at least in part on: the channel measurements; and the report quantity configuration; and the CSI feedback report comprising a first CSI feedback and a second CSI feedback. ### Claim 16 (depends on 15) The wireless device of claim 15, wherein the first CSI feedback comprises one CSI for each of the K NZP CSI-RS resources. ### Claim 17 (depends on 15) The wireless device of claim 15, wherein the second CSI feedback comprises a CSI for one of non-coherent joint, NC-JT, transmission and Ultra Reliable Low Latency, URLL, transmission. ### Claim 18 (depends on 15) The wireless device of claim 15, wherein the second CSI feedback comprises a first rank indicator and a first precoding matrix indicator associated with a first NZP CSI-RS resource and a second rank indicator and a second precoding matrix indicator associated with a second NZP CSI-RS resource, and a joint channel quality indicator conditioned on the first and the second rank and precoding matrix indicators. ### Claim 19 (depends on 15) The wireless device of claim 15, wherein the second CSI feedback comprises a first rank indicator and a first layer indicator associated with a first NZP CSI-RS resource, and a second rank indicator and a second layer indicator associated with a second NZP CSI-RS resource, and a joint channel quality indicator conditioned on the first and the second rank and layer indicators. ### Claim 20 (depends on 15) The wireless device of claim 15, wherein the second CSI feedback further includes identities of the first and the second NZP CSI-RS resources.