# US 2022/0046624 A1 · Beam-based initial transmissions, re-transmissions, and search spaces > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2022/0046624 A1 - Document ID: US20220046624A1 - Status: Published application - Kind: A1 - Application number: 17/444,306 - Filed: 2021-08-03 - Published: 2022-02-10 - Earliest claimed: 2020-08-06 - Assignees: QUALCOMM Incorporated - Applicants: QUALCOMM Incorporated - Inventors: Kazuki TAKEDA; Alberto RICO ALVARINO; Le LIU; Xipeng ZHU; Prasad Reddy KADIRI; Umesh PHUYAL - Web page: https://patentgrep.com/patent/US20220046624A1 ## CPC - H04B 7/06966: {using beam correspondence; using channel reciprocity, e.g. downlink beam training based on uplink sounding reference signal [SRS]} - H04L 1/1845: {Combining techniques, e.g. code combining} - H04L 1/1887: {Scheduling and prioritising arrangements} - H04L 1/189: {Transmission or retransmission of more than one copy of a message} - H04L 5/0053: {Allocation of signalling, i.e. of overhead other than pilot signals} - H04L 5/0094: {Indication of how sub-channels of the path are allocated} - H04W 72/046: {the resource being in the space domain, e.g. beams} - H04W 72/23: in the downlink direction of a wireless link, i.e. towards a terminal - H04W 72/54: based on quality criteria - H04L 5/0023: {Time-frequency-space} - 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 Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, from a base station, an indication of a first search space for control messages from the base station, an indication of a first downlink beam for the first search space, an indication of a second search space for control messages from the base station, and an indication of a second downlink beam for the second search space. The UE may monitor the first search space, using a spatial filter based at least in part on the first downlink beam, for an initial transmission of data from the base station. Additionally, the UE may monitor the second search space, using a spatial filter based at least in part on the second downlink beam, for re-transmission of the data from the base station. Numerous other aspects are provided. ## Claims ### Claim 1 An apparatus for wireless communication at a user equipment (UE), comprising: a memory; and one or more processors, coupled to the memory, configured to: receive, from a base station, an indication of a first search space for control messages from the base station and an indication of a first downlink beam for the first search space; receive, from the base station, an indication of a second search space for control messages from the base station and an indication of a second downlink beam for the second search space; monitor the first search space, using a spatial filter based at least in part on the first downlink beam, for an initial transmission of data from the base station; and monitor the second search space, using a spatial filter based at least in part on the second downlink beam, for a re-transmission of the data from the base station. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the first downlink beam is associated with a first transmission configuration indicator (TCI) state, and the second downlink beam is associated with a second TCI state. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein the first search space is associated with a first control resource set (CORESET), and the second search space is associated with a second CORESET. ### Claim 4 (depends on 1) The apparatus of claim 1, wherein the first search space is monitored for downlink control information (DCI) scrambled with a group identifier associated with a group of UEs including the UE. ### Claim 5 (depends on 1) The apparatus of claim 1, wherein the second search space is monitored for downlink control information (DCI) scrambled with a group identifier associated with a group of UEs including the UE or for DCI scrambled with a specific identifier associated with the UE. ### Claim 6 (depends on 1) The apparatus of claim 1, wherein the one or more processors are further configured to: detect an error when attempting to decode a message that was received while monitoring the first search space, wherein monitoring the second search space is based at least in part on detecting the decoding error. ### Claim 7 (depends on 1) The apparatus of claim 1, wherein the one or more processors are further configured to: receive, from the base station, information activating the second search space, wherein monitoring the second search space is based at least in part on the information activating the second search space. ### Claim 8 (depends on 7) The apparatus of claim 7, wherein the one or more processors are further configured to: detect an error when attempting to decode a message that was received while monitoring the first search space; and transmit, to the base station, a signal indicating the decoding error, wherein the information activating the second search space is received based at least in part on the signal indicating the decoding error. ### Claim 9 (depends on 1) The apparatus of claim 1, wherein the one or more processors are further configured to: determine that the second downlink beam is preferred to one or more additional downlink beams, wherein the second search space is monitored based at least in part on the second downlink beam being determined to be preferred to the one or more additional downlink beams. ### Claim 10 (depends on 9) The apparatus of claim 9, wherein the second downlink beam is determined to be preferred to the one or more additional downlink beams based at least in part on a signal strength of the second downlink beam, an interference strength of the second downlink beam, or a quality indicator associated with the second downlink beam. ### Claim 11 (depends on 9) The apparatus of claim 9, wherein the one or more processors are further configured to: detect an error when attempting to decode a message that was received while monitoring the first search space; and transmit, to the base station, information related to a strength of the second downlink beam, wherein the second search space is monitored in connection with the information, related to the strength of the second downlink beam, being transmitted. ### Claim 12 (depends on 1) The apparatus of claim 1, wherein the indication of the first search space comprises a data structure that includes a list of associated transmission configuration indicator (TCI) states that include a TCI state for the first downlink beam. ### Claim 13 (depends on 1) The apparatus of claim 1, wherein the indication of the first search space comprises a data structure that includes an identifier, wherein the identifier is associated with one or more transmission configuration indicator (TCI) states that include a TCI state for the first downlink beam. ### Claim 14 (depends on 1) The apparatus of claim 1, wherein the one or more processors are further configured to: decode a message from the base station by soft-combining a signal scheduled by downlink control information (DCI) received in the first search space with an additional signal scheduled by DCI received in the second search space. ### Claim 15 (depends on 1) The apparatus of claim 1, wherein the one or more processors are further configured to: receive, from the base station, an indication of a third search space for control messages from the base station and an indication of a third downlink beam for the third search space; monitor the third search space, using a spatial filter based at least in part on the third downlink beam, for a re-transmission of the data from the base station; and decoding a message from the base station by soft-combining a signal scheduled by downlink control information (DCI) received in the second search space with an additional signal scheduled by DCI received in the third search space. ### Claim 16 (depends on 1) The apparatus of claim 1, wherein the one or more processors are further configured to: detect an error when attempting to decode a message that was received while monitoring the second search space; and transmit, to the base station, a signal indicating the decoding error, wherein the signal indicating the decoding error is transmitted on an uplink resource associated with the second search space. ### Claim 17 (depends on 1) The apparatus of claim 1, wherein the one or more processors are further configured to: receive, from the base station, an indication of a third search space for control messages from the base station and an indication of a third downlink beam for the third search space; detect an error when attempting to decode a message that was received while monitoring the second search space; and transmit, to the base station, a signal indicating the decoding error, wherein the signal indicating the decoding error is transmitted on an uplink resource associated with the third search space. ### Claim 18 An apparatus for wireless communication at a base station, comprising: a memory; and one or more processors, coupled to the memory, configured to: transmit, to a user equipment (UE), an indication of a first search space for control messages from the base station and an indication of a first downlink beam for the first search space; transmit, to the UE, an indication of a second search space for control messages from the base station and an indication of a second downlink beam for the second search space; send an initial transmission of data within the first search space and using the first downlink beam; and send a re-transmission of the data within the second search space and using the second downlink beam. ### Claim 19 An apparatus for wireless communication at a user equipment (UE), comprising: a memory; and one or more processors, coupled to the memory, configured to: receive, from a base station, an indication of a change from a first transmission configuration indicator (TCI) state to a second TCI state, wherein the first TCI state is associated with one or more first control channel monitoring occasions, and the second TCI state is associated with one or more second control channel monitoring occasions different than the one or more first control channel monitoring occasions; monitor for messages from the base station within the one or more second control channel monitoring occasions based at least in part on the indication of the change from the first TCI state to the second TCI state; and receive, from the base station, a control message based at least in part on the one or more second control channel monitoring occasions being monitored. ### Claim 20 (depends on 19) The apparatus of claim 19, wherein a first search space that provides configurations for identifying the one or more first control channel monitoring occasions is associated with a first control resource set (CORESET), and a second search space that provides configurations for identifying the one or more second control channel monitoring occasions is associated with a second CORESET. ### Claim 21 (depends on 20) The apparatus of claim 20, wherein the first search space and the second search space are defined in a data structure that associates an identifier of the first TCI state with the first search space and an identifier of the second TCI state with the second search space. ### Claim 22 (depends on 20) The apparatus of claim 20, wherein the first TCI state and the second TCI state are defined in a data structure that associates an identifier of the first search space with the first TCI state and an identifier of the second search space with the second TCI state. ### Claim 23 (depends on 19) The apparatus of claim 19, wherein the one or more processors are further configured to: receive, from the base station, an indication of an additional search space; and monitor for messages from the base station within the additional search space, wherein the messages within the additional search space are unicast messages, and the messages within the one or more second control channel monitoring occasions are multicast messages. ### Claim 24 (depends on 23) The apparatus of claim 23, wherein the additional search space and the one or more second control channel monitoring occasions share a source reference signal, and both the one or more second control channel monitoring occasions and the additional search space are monitored. ### Claim 25 (depends on 19) The apparatus of claim 19, wherein the one or more processors, to monitor for messages from the base station within the one or more second control channel monitoring occasions, ae configured to monitor for messages from the base station within a portion of candidates that are included in the one or more second control channel monitoring occasions. ### Claim 26 (depends on 25) The apparatus of claim 25, wherein the portion of candidates included in the one or more second control channel monitoring occasions that are monitored are selected based at least in part on candidates that are included in all search spaces across all possible TCI states. ### Claim 27 (depends on 25) The apparatus of claim 25, wherein the portion of candidates included in the one or more second control channel monitoring occasions that are monitored are selected based at least in part on candidates that are included in all search spaces associated with the second TCI state. ### Claim 28 (depends on 25) The apparatus of claim 25, wherein the portion of candidates included in the one or more second control channel monitoring occasions that are monitored are selected based at least in part on a largest number of candidates that are included in a span and that are largest amongst all possible TCI states associated with the span. ### Claim 29 (depends on 19) The apparatus of claim 19, wherein the one or more processors are further configured to: monitor for messages from the base station within the one or more first control channel monitoring occasions before receiving the indication of the change from the first TCI state to the second TCI state, wherein the one or more second control channel monitoring occasions are monitored in connection with a threshold time duration, after receiving the indication of the change from the first TCI state to the second TCI state, being satisfied. ### Claim 30 An apparatus for wireless communication at a base station, comprising: a memory; and one or more processors, coupled to the memory, configured to: transmit, to a user equipment (UE), an indication of a change from a first transmission configuration indicator (TCI) state to a second TCI state, wherein the first TCI state is associated with one or more first control channel monitoring occasions, and the second TCI state is associated with one or more second control channel monitoring occasions different than the one or more first control channel monitoring occasions; and transmit, to the UE, a control message within the one or more second control channel monitoring occasions based at least in part on the indication of the change from the first TCI state to the second TCI state.