# US 2021/0344403 A1 · Methods and apparatus to facilitate cross-carrier beam association > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0344403 A1 - Document ID: US20210344403A1 - Status: Published application - Kind: A1 - Application number: 17/179,285 - Filed: 2021-02-18 - Published: 2021-11-04 - Earliest claimed: 2020-04-30 - Assignees: QUALCOMM Incorporated - Applicants: QUALCOMM Incorporated - Inventors: Sungwoo PARK; Wooseok NAM; Kiran VENUGOPAL; Tianyang BAI; Tao LUO - Web page: https://patentgrep.com/patent/US20210344403A1 ## CPC - H04B 7/088: {using beam selection} - H04B 7/06952: {Selecting one or more beams from a plurality of beams, e.g. beam training, management or sweeping} - H04W 24/10: Scheduling measurement reports {; Arrangements for measurement reports} - H04W 48/12: using downlink control channel - H04W 48/16: Discovering, processing access restriction or access information - H04W 56/001: {Synchronization between nodes} - H04W 76/27: Transitions between radio resource control [RRC] states - H04W 74/0833: Random access procedures, e.g. with 4-step access - H04B: TRANSMISSION - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract Apparatus, methods, and computer-readable media for facilitating cross-carrier beam association are disclosed herein. An example method for wireless communication at a UE includes receiving, from a base station, an indication of a cross-carrier beam association associated with a first carrier and a second carrier different than the first carrier. The example method also includes determining an association between a first set of beams of the first carrier and a second set of beams of the second carrier based on the indication of the cross-carrier beam association. Additionally, the example method includes receiving on the first set of beams and the second set of beams based on the determined cross-carrier beam association. ## Claims ### Claim 1 A method of wireless communication at a user equipment (UE), comprising: receiving, from a base station, an indication of a cross-carrier beam association associated with a first carrier and a second carrier different than the first carrier; determining an association between a first set of beams of the first carrier and a second set of beams of the second carrier based on the indication of the cross-carrier beam association; and receiving on the first set of beams and the second set of beams based on the determined cross-carrier beam association. ### Claim 2 (depends on 1) The method of claim 1, wherein the indication indicates that a synchronization signal block (SSB) of the first set of beams is associated with a random access channel (RACH) occasion (RO), the method further comprising: selecting a first subset of beams of the first set of beams based on measurements of an SSB received on the first carrier; determining a second subset of beams of the second set of beams, the second subset of beams corresponding to the first subset of beams based on the cross-carrier beam association; and transmitting, to the base station, a RACH message through the second subset of beams at the RO. ### Claim 3 (depends on 2) The method of claim 2, further comprising: measuring SSBs received through the second subset of beams; and refining beams in the second subset of beams based on the measured SSBs received through the second set of beams. ### Claim 4 (depends on 1) The method of claim 1, wherein the first set of beams comprises a first quantity of beams and the second set of beams comprises a second quantity of beams that is a same quantity as the first quantity of beams or that is a different quantity than the first quantity of beams. ### Claim 5 (depends on 1) The method of claim 1, wherein the first set of beams comprises N beams and the second set of beams comprises N*M beams. ### Claim 6 (depends on 1) The method of claim 1, wherein the first carrier and the second carrier are inter-band carriers. ### Claim 7 (depends on 6) The method of claim 6, wherein the first carrier is associated with a first frequency range and the second carrier is associated with a second frequency range that is a same frequency range as the first frequency range or that is a different frequency range than the second frequency range. ### Claim 8 (depends on 1) The method of claim 1, wherein the first carrier and the second carrier are intra-band carriers. ### Claim 9 (depends on 1) The method of claim 1, wherein the first set of beams are each associated with a first beam width, wherein the second set of beams are each associated with a second beam width, and wherein the second set of beams based on the second beam width overlap the first set of beams based on the first beam width. ### Claim 10 (depends on 9) The method of claim 9, wherein the second beam width is a same beam width as the first beam width or that is a different beam width than the first beam width. ### Claim 11 (depends on 9) The method of claim 9, wherein the second beam width is approximately equal to 1/M the first beam width. ### Claim 12 (depends on 1) The method of claim 1, wherein the cross-carrier beam association between the first carrier and the second carrier is determined based on a quasi co-location (QCL) relationship of the first set of beams and the second set of beams. ### Claim 13 (depends on 1) The method of claim 1, wherein the indication is received via system information (SI) or radio resource control (RRC) signaling. ### Claim 14 (depends on 1) The method of claim 1, further comprising: transmitting, to the base station, a capability indicating support of cross-carrier beam association, and wherein the indication is received in a radio resource control (RRC) message. ### Claim 15 An apparatus for wireless communication at a user equipment (UE), comprising: a memory; and at least one processor coupled to the memory and configured to: receive, from a base station, an indication of a cross-carrier beam association associated with a first carrier and a second carrier different than the first carrier; determine an association between a first set of beams of the first carrier and a second set of beams of the second carrier based on the indication of the cross-carrier beam association; and receive on the first set of beams and the second set of beams based on the determined cross-carrier beam association. ### Claim 16 (depends on 15) The apparatus of claim 15, wherein the indication indicates that a synchronization signal block (SSB) of the first set of beams is associated with a random access channel (RACH) occasion (RO), the at least one processor further configured to: select a first subset of beams of the first set of beams based on measurements of an SSB received on the first carrier; determine a second subset of beams of the second set of beams, the second subset of beams corresponding to the first subset of beams based on the cross-carrier beam association; and transmit, to the base station, a RACH message through the second subset of beams at the RO. ### Claim 17 A method of wireless communication at a base station, comprising: determining a cross-carrier beam association between a first set of beams of a first carrier and a second set of beams of a second carrier, the first carrier being different than the second carrier; transmitting, to a user equipment (UE), an indication of the cross-carrier beam association associated with the first carrier and the second carrier; and transmitting, to the UE, on the first set of beams and the second set of beams based on the determined cross-carrier beam association. ### Claim 18 (depends on 17) The method of claim 17, wherein the indication indicates that a synchronization signal block (SSB) of the first set of beams is associated with a random access channel (RACH) occasion (RO), the method further comprising: receiving, from the UE, a RACH message through a subset of beams of the second set of beams at the RO. ### Claim 19 (depends on 17) The method of claim 17, wherein the first set of beams comprises a first quantity of beams and the second set of beams comprises a second quantity of beams that is a same quantity as the first quantity of beams or that is a different quantity than the first quantity of beams. ### Claim 20 (depends on 17) The method of claim 17, wherein the first set of beams comprises N beams and the second set of beams comprises N*M beams. ### Claim 21 (depends on 17) The method of claim 17, wherein the first carrier and the second carrier are inter-band carriers. ### Claim 22 (depends on 21) The method of claim 21, wherein the first carrier is associated with a first frequency range and the second carrier is associated with a second frequency range that is a same frequency range as the first frequency range or that is a different frequency range than the second frequency range. ### Claim 23 (depends on 17) The method of claim 17, wherein the first carrier and the second carrier are intra-band carriers. ### Claim 24 (depends on 17) The method of claim 17, wherein the first set of beams are each associated with a first beam width, wherein the second set of beams are each associated with a second beam width, and wherein the second set of beams based on the second beam width overlap the first set of beams based on the first beam width. ### Claim 25 (depends on 24) The method of claim 24, wherein the second beam width is a same beam width as the first beam width or that is a different beam width than the first beam width. ### Claim 26 (depends on 24) The method of claim 24, wherein the second beam width is approximately equal to 1/M the first beam width. ### Claim 27 (depends on 17) The method of claim 17, wherein the cross-carrier beam association between the first carrier and the second carrier is determined based on a quasi co-location (QCL) relationship of the first set of beams and the second set of beams. ### Claim 28 (depends on 17) The method of claim 17, wherein the indication is transmitted via system information (SI) or radio resource control (RRC) signaling. ### Claim 29 (depends on 17) The method of claim 17, further comprising: receiving, from the UE, a capability indicating support of cross-carrier beam association, and wherein the indication is transmitted in a radio resource control (RRC) message. ### Claim 30 An apparatus for wireless communication at a base station, comprising: a memory; and at least one processor coupled to the memory and configured to: determine a cross-carrier beam association between a first set of beams of a first carrier and a second set of beams of a second carrier, the first carrier being different than the second carrier; transmit, to a user equipment (UE), an indication of the cross-carrier beam association associated with the first carrier and the second carrier; and transmit, to the UE, on the first set of beams and the second set of beams based on the determined cross-carrier beam association.