# US 11,909,480 B2 · Method and apparatus for non-codebook based UL transmission > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,909,480 B2 - Document ID: US11909480B2 - Status: Granted - Kind: B2 - Application number: 17/040,605 - Filed: 2018-03-23 - Published: 2021-04-22 - Granted: 2024-02-20 - Earliest claimed: 2018-03-23 - Assignees: Lenovo (Beijing) Limited - Applicants: Lenovo (Beijing) Limited - Inventors: Chenxi Zhu; Bingchao Liu; Wei Ling; Yingying Li - Web page: https://patentgrep.com/patent/US11909480B2 ## CPC - H04B 7/0626: {Channel coefficients, e.g. channel state information [CSI]} - H04B 7/088: {using beam selection} - H04B 7/0639: {Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection} - H04B 7/06966: {using beam correspondence; using channel reciprocity, e.g. downlink beam training based on uplink sounding reference signal [SRS]} - H04L 1/0003: {by switching between different modulation schemes} - H04W 24/10: Scheduling measurement reports {; Arrangements for measurement reports} - H04W 52/16: Deriving transmission power values from another channel - H04W 52/223: {predicting future states of the transmission} - H04W 72/23: in the downlink direction of a wireless link, i.e. towards a terminal - 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 Method and apparatus for reduction of the signaling/resource overhead caused by SRS transmission in UL are disclosed. One method of a UE for the reduction of the signaling/resource overhead caused by SRS transmission in UL includes performing precoding on UL transmission with a precoding matrix corresponding to a CRI, in the case of a frequency of UL and DL being in a same band and Tx/Rx beam correspondence, wherein, the CRI corresponding to the precoding matrix is determined according to a measurement on DL channel quality; and transmitting a report of the measurement on DL channel quality to a base station. ## Claims ### Claim 1 An apparatus for wireless communication, the apparatus comprising: a transceiver; a processor; and a memory coupled to the processor, the processor configured to cause the apparatus to: receive a channel state information-reference signal (CSI-RS) resource identifier (CRI) that indicates a resource configuration for CSI-RS for downlink (DL) channel measurement; measure a layer 1 reference signal received power (L1-RSRP) on the CSI-RS; transmit a report of the L1-RSRP measurement to a base station; determine a precoding matrix for non-codebook (non-CB) uplink (UL) transmission based on the CRI and the L1-RSRP measurement in response to an UL frequency and a DL frequency being in a same band; and perform a non-CB UL transmission using the precoding matrix. ### Claim 2 (depends on 1) The apparatus according to claim 1, wherein; the processor calculates a power offset between uplink and downlink based on a difference between uplink transmission power and downlink channel state information-reference signal transmission power, as well as a difference between transmission antenna/circuit gain and receiving antenna/circuit gain; and the transceiver transmits the power offset between uplink and downlink. ### Claim 3 (depends on 2) The apparatus according to claim 2, wherein the channel state information-reference signal resource identifier corresponding to the precoding matrix is determined according to the measurement of the downlink channel quality and the power offset between uplink and downlink. ### Claim 4 (depends on 1) The apparatus according to claim 1, wherein the transceiver receives uplink grant, including modulation and Coding Scheme which is based on the report of the measurement of the downlink channel quality from the base station. ### Claim 5 (depends on 4) The apparatus according to claim 4, wherein the transceiver receives uplink grant, including modulation and coding scheme which is based on the report of the measurement of the downlink channel quality and the power offset between uplink and downlink from the base station. ### Claim 6 (depends on 1) The apparatus according to claim 1, wherein the processor, learns available uplink ports from the channel state information-reference signal resource identifier indicated by the base station. ### Claim 7 (depends on 1) The apparatus according to claim 1, wherein the processor, learns available uplink ports from a dummy sounding reference signal resource identifier indicated by the base station, wherein, resources for the dummy sounding reference signal are associated with resources for the channel state information-reference signal indicated by the base station. ### Claim 8 (depends on 6) The apparatus according to claim 6, wherein the transceiver transmits a maximum number of supported uplink ports corresponding to resources for the channel state information-reference signal, as well as sets of resources for the channel state information-reference signal which can be transmitted simultaneously, to the base station by a higher layer message. ### Claim 9 A method comprises: receiving a channel state information-reference signal (CSI-RS) resource identifier (CRI) that indicates a resource configuration for CSI-RS for downlink (DL) channel measurement; measuring a layer 1 reference signal received power (L1-RSRP) on the CSI-RS; transmitting a report of the L1-RSRP measurement to a base station; determining a precoding matrix for non-codebook (non-CB) uplink (UL) transmission based on the CRI and the L1-RSRP measurement in response to an UL frequency and a DL frequency being in a same band; and performing a non-CB UL transmission using the precoding matrix. ### Claim 10 (depends on 9) The method according to claim 9, further comprising: calculating a power offset between uplink and downlink based on a difference between uplink transmission power and downlink channel state information-reference signal transmission power, as well as a difference between transmission antenna/circuit gain and Receiving antenna/circuit gain; and transmitting the power offset between uplink and downlink. ### Claim 11 (depends on 10) The method according to claim 10, wherein, the channel state information-reference signal resource identifier corresponding to the precoding matrix is determined according to the measurement of the downlink channel quality and the power offset between uplink and downlink. ### Claim 12 (depends on 9) The method according to claim 9, further comprises receiving uplink grant, including modulation and coding scheme which is based on the report of the measurement of the downlink channel quality from the base station. ### Claim 13 (depends on 12) The method according to claim 12, further comprises receiving uplink grant, including modulation and coding scheme which is based on the report of the measurement of the downlink channel quality and the power offset between uplink and downlink from the base station. ### Claim 14 An apparatus for wireless communication, the apparatus comprising: a transceiver; a processor; and a memory coupled to the processor, the processor configured to cause the apparatus to: transmit a channel state information-reference signal (CSI-RS) resource identifier (CRI) that indicates a resource configuration for CSI-RS for downlink (DL) channel measurement; receive a report of a layer 1 reference signal received power (L1-RSRP) measurement on the CSI-RS; and receive a non-codebook (non-CB) uplink (UL) transmission using a precoding matrix, wherein the precoding matrix for the non-CB UL transmission based on the CRI and the L1-RSRP measurement in response to an UL frequency and a DL frequency being in a same band. ### Claim 15 (depends on 14) The apparatus according to claim 14, wherein; the transceiver receives a power offset between uplink and downlink from the user equipment, wherein the power offset between uplink and downlink is based on a difference between uplink transmission power and downlink channel state information-reference signal transmission power, as well as a difference between transmission antenna/circuit gain and receiving antenna/circuit gain of the user equipment; and the processor determines ports used for uplink transmission based on the report of the measurement of the downlink channel quality and the power offset between uplink and downlink. ### Claim 16 (depends on 14) The apparatus according to claim 14, wherein the transceiver transmits uplink grant, including modulation and coding scheme which is based on the report of the measurement of the downlink channel quality to the user equipment. ### Claim 17 (depends on 16) The apparatus according to claim 16, wherein the transceiver transmits uplink grant, including modulation and Coding Scheme which is based on the report of the measurement of the downlink channel quality and the power offset between uplink and downlink to the user equipment. ### Claim 18 (depends on 14) The apparatus according to claim 14, wherein the processor indicates available uplink ports in a channel state information-reference signal resource identifier to the user equipment, wherein each of resources for the channel state information-reference signal corresponding to the available uplink ports belongs to different sets of resources for the channel state information-reference signal. ### Claim 19 (depends on 14) The apparatus according to claim 14, wherein the processor indicates available uplink ports in a dummy sounding reference signal resource identifier to the user equipment, wherein resources for the dummy sounding reference signal are associated with resources for the channel state information-reference signal indicated to the user equipment. ### Claim 20 (depends on 18) The apparatus according to claim 18, wherein the transceiver receives a higher layer message including a maximum number of supported uplink ports corresponding to resource for the channel state information-reference signal, as well as sets of resources for the channel state information-reference signal which can be transmitted simultaneously from the user equipment.