# US 2019/0357252 A1 · Listen before talk techniques in shared millimeter wave radio frequency spectrum > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0357252 A1 - Document ID: US20190357252A1 - Status: Published application - Kind: A1 - Application number: 16/372,365 - Filed: 2019-04-01 - Published: 2019-11-21 - Earliest claimed: 2018-05-21 - Assignees: QUALCOMM Incorporated - Applicants: QUALCOMM Incorporated - Inventors: Jing Sun; Xiaoxia Zhang; Arumugam Chendamarai Kannan; Tamer Kadous; Yongbin Wei; Aleksandar Damnjanovic - Web page: https://patentgrep.com/patent/US20190357252A1 ## CPC - H04W 74/0808: using carrier sensing, e.g. carrier sense multiple access [CSMA] - H04W 72/23: in the downlink direction of a wireless link, i.e. towards a terminal - H04W 72/046: {the resource being in the space domain, e.g. beams} - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract Methods, systems, and devices for wireless communications are described in which base stations and user equipment (UEs) may transmit using identified wireless resources in millimeter wave (mmW) radio frequency spectrum. A UE may receive an uplink grant from a base station that indicates uplink resources for transmission of uplink data from the UE to the base station in a shared mmW radio frequency spectrum band. An indication of a duration of a listen-before-talk (LBT) procedure may be provided in or with the uplink grant. The UE may perform, responsive to receiving the uplink grant, the LBT procedure to determine that the shared mmW radio frequency spectrum band is available for the uplink transmission. Based on the outcome of the LBT procedure, the UE may transmit the uplink data to the base station using the uplink resources indicated in the uplink grant. ## Claims ### Claim 1 A method for wireless communication at a user equipment (UE), comprising: receiving an uplink grant from a base station that indicates uplink resources for transmission of uplink data from the UE to the base station in a shared millimeter wave (mmW) radio frequency spectrum band; performing, responsive to receiving the uplink grant, a listen-before-talk (LBT) procedure to determine that the shared mmW radio frequency spectrum band is available for the transmission of the uplink data; and transmitting, based at least in part on the shared mmW radio frequency spectrum band being available for the transmission of the uplink data, the uplink data to the base station using the uplink resources indicated in the uplink grant. ### Claim 2 (depends on 1) The method of claim 1, further comprising: receiving, from the base station, an indication of a duration of the LBT procedure. ### Claim 3 (depends on 2) The method of claim 2, wherein the LBT procedure is a clear channel assessment (CCA) check using energy detection (ED) for a duration of a CCA observation time, wherein the CCA observation time is based in part on a random number that is selected for a number of CCA slots to measure channel energy, and wherein the receiving the indication of the duration of the LBT procedure comprises receiving the random number from the base station. ### Claim 4 (depends on 2) The method of claim 2, wherein the indication of the duration of the LBT procedure is included in the uplink grant or transmitted together with the uplink grant. ### Claim 5 (depends on 2) The method of claim 2, wherein the duration of the LBT procedure is synchronized with a frame boundary, a slot boundary, or a symbol boundary of a frame structure used for communications between the UE and the base station. ### Claim 6 (depends on 2) The method of claim 2, wherein the indication of the duration of the LBT procedure further indicates an offset value, and wherein the LBT procedure is initiated after a time period associated with the offset value. ### Claim 7 (depends on 1) The method of claim 1, wherein the uplink grant is a short control signaling transmission that is exempt from the LBT procedure. ### Claim 8 (depends on 1) The method of claim 1, further comprising: abandoning the transmitting of the uplink data based at least in part on the shared mmW radio frequency spectrum band being unavailable for the transmission of the uplink data. ### Claim 9 (depends on 1) The method of claim 1, wherein the uplink grant is received from the base station during a downlink transmission from the base station in a previous channel occupancy time (COT) or transmission opportunity (TxOP). ### Claim 10 (depends on 9) The method of claim 9, wherein the uplink grant further indicates an ending time of the previous COT or TxOP, and wherein the UE initiates the LBT procedure after the ending time of the previous COT or TxOP. ### Claim 11 (depends on 9) The method of claim 9, wherein at least a portion of a duration of the LBT procedure overlaps with a portion of the previous COT or TxOP. ### Claim 12 (depends on 11) The method of claim 11, wherein the previous COT or TxOP includes a transmission for a different UE. ### Claim 13 (depends on 1) The method of claim 1, wherein one or more of the uplink grant or transmission of the uplink data are transmitted via a beamformed transmission beam. ### Claim 14 A method for wireless communication at a base station, comprising: allocating uplink resources to a user equipment (UE) for an uplink transmission of uplink data from the UE to the base station in a shared millimeter wave (mmW) radio frequency spectrum band; transmitting an uplink grant to the UE indicating the uplink resources; and monitoring for the uplink transmission from the UE using the uplink resources indicated in the uplink grant, wherein the UE is to perform a listen-before-talk (LBT) procedure prior to the uplink transmission. ### Claim 15 (depends on 14) The method of claim 14, further comprising: transmitting, to the UE, an indication of a duration of the LBT procedure. ### Claim 16 (depends on 15) The method of claim 15, wherein the LBT procedure is a clear channel assessment (CCA) check using energy detection (ED) for a duration of a CCA observation time, wherein the CCA observation time is based in part on a random number that is selected for a number of CCA slots to measure channel energy, and wherein the method further comprises: randomly selecting the random number for the CCA, and providing the random number to the UE as the indication of the duration of the LBT procedure. ### Claim 17 (depends on 15) The method of claim 15, wherein the indication of the duration of the LBT procedure is included in the uplink grant or transmitted together with the uplink grant. ### Claim 18 (depends on 15) The method of claim 15, wherein the duration of the LBT procedure is synchronized with a frame boundary, a slot boundary, or a symbol boundary of a frame structure used for communications between the UE and the base station. ### Claim 19 (depends on 15) The method of claim 15, wherein the UE is a first UE, and wherein the method further comprises: determining that a second uplink transmission of a second UE has a second duration that is less than the duration of the LBT procedure of the first UE; scheduling the second uplink transmission of the second UE within the duration of the LBT procedure of the first UE; and transmitting a second uplink grant to the second UE. ### Claim 20 (depends on 19) The method of claim 19, further comprising: determining an offset value between the uplink grant and a start of the LBT procedure at the first UE based at least in part on a duration of the second uplink transmission of the second UE; and indicating the offset value to the first UE. ### Claim 21 (depends on 19) The method of claim 19, wherein the second UE is selected based at least in part on a cross-UE interference between transmission beams of the first UE and the second UE being below a threshold value. ### Claim 22 (depends on 14) The method of claim 14, further comprising: transmitting a second uplink grant to a different UE during a duration of the LBT procedure. ### Claim 23 (depends on 14) The method of claim 14, wherein the uplink grant is a short control signaling transmission that is exempt from the LBT procedure. ### Claim 24 (depends on 14) The method of claim 14, wherein the monitoring comprises: determining that the uplink transmission is not received; and reusing the granted resource for transmission or reception for one or more different UEs. ### Claim 25 (depends on 14) The method of claim 14, wherein the uplink grant is transmitted to the UE during a downlink transmission of a previous channel occupancy time (COT) or transmission opportunity (TxOP). ### Claim 26 (depends on 25) The method of claim 25, wherein the uplink grant further indicates an ending time of the previous COT or TxOP, and wherein the UE initiates the LBT procedure after the ending time of the previous COT or TxOP. ### Claim 27 (depends on 25) The method of claim 25, wherein at least a portion of a duration of the LBT procedure overlaps with a portion of the previous COT or TxOP. ### Claim 28 (depends on 25) The method of claim 25, wherein the uplink grant is transmitted from the base station before an end of the downlink transmission of downlink shared channel data. ### Claim 29 (depends on 14) The method of claim 14, wherein one or more of the uplink grant or uplink transmission are transmitted via a beamformed transmission beam. ### Claim 30 An apparatus for wireless communication at a user equipment (UE), comprising: a processor, memory in electronic communication with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to: receive an uplink grant from a base station that indicates uplink resources for transmission of uplink data from the UE to the base station in a shared millimeter wave (mmW) radio frequency spectrum band; perform, responsive to receiving the uplink grant, a listen-before-talk (LBT) procedure to determine that the shared mmW radio frequency spectrum band is available for the transmission of the uplink data; and transmit, based at least in part on the shared mmW radio frequency spectrum band being available for the transmission of the uplink data, the uplink data to the base station using the uplink resources indicated in the uplink grant. ### Claim 31 (depends on 30) The apparatus of claim 30, wherein the instructions are further executable by the processor to cause the apparatus to: receive, from the base station, an indication of a duration of the LBT procedure. ### Claim 32 (depends on 31) The apparatus of claim 31, wherein the LBT procedure is a clear channel assessment (CCA) check using energy detection (ED) for a duration of a CCA observation time, wherein the CCA observation time is based in part on a random number that is selected for a number of CCA slots to measure channel energy, and wherein the receiving the indication of the duration of the LBT procedure comprises receiving the random number from the base station. ### Claim 33 (depends on 31) The apparatus of claim 31, wherein the indication of the duration of the LBT procedure is included in the uplink grant or transmitted together with the uplink grant. ### Claim 34 (depends on 31) The apparatus of claim 31, wherein the duration of the LBT procedure is synchronized with a frame boundary, a slot boundary, or a symbol boundary of a frame structure used for communications between the UE and the base station. ### Claim 35 (depends on 31) The apparatus of claim 31, wherein the indication of the duration of the LBT procedure further indicates an offset value, and wherein the LBT procedure is initiated after a time period associated with the offset value. ### Claim 36 (depends on 30) The apparatus of claim 30, wherein the uplink grant is a short control signaling transmission that is exempt from the LBT procedure. ### Claim 37 (depends on 30) The apparatus of claim 30, wherein the instructions are further executable by the processor to cause the apparatus to: abandon the transmitting of the uplink data based at least in part on the shared mmW radio frequency spectrum band being unavailable for the transmission of the uplink data. ### Claim 38 (depends on 30) The apparatus of claim 30, wherein the uplink grant is received from the base station during a downlink transmission from the base station in a previous channel occupancy time (COT) or transmission opportunity (TxOP). ### Claim 39 (depends on 38) The apparatus of claim 38, wherein the uplink grant further indicates an ending time of the previous COT or TxOP, and wherein the UE initiates the LBT procedure after the ending time of the previous COT or TxOP. ### Claim 40 (depends on 38) The apparatus of claim 38, wherein at least a portion of a duration of the LBT procedure overlaps with a portion of the previous COT or TxOP. ### Claim 41 (depends on 40) The apparatus of claim 40, wherein the previous COT or TxOP includes a transmission for a different UE. ### Claim 42 (depends on 30) The apparatus of claim 30, wherein one or more of the uplink grant or transmission of the uplink data are transmitted via a beamformed transmission beam. ### Claim 43 An apparatus for wireless communication at a base station, comprising: a processor, memory in electronic communication with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to: allocate uplink resources to a user equipment (UE) for an uplink transmission of uplink data from the UE to the base station in a shared millimeter wave (mmW) radio frequency spectrum band; transmit an uplink grant to the UE indicating the uplink resources; and monitor for the uplink transmission from the UE using the uplink resources indicated in the uplink grant, wherein the UE is to perform a listen-before-talk (LBT) procedure prior to the uplink transmission. ### Claim 44 (depends on 43) The apparatus of claim 43, wherein the instructions are further executable by the processor to cause the apparatus to: transmit, to the UE, an indication of a duration of the LBT procedure. ### Claim 45 (depends on 44) The apparatus of claim 44, wherein the LBT procedure is a clear channel assessment (CCA) check using energy detection (ED) for a duration of a CCA observation time, and wherein the instructions are further executable by the processor to cause the apparatus to: randomly select the random number for the CCA procedure; and provide the random number to the UE as the indication of the duration of the LBT procedure. ### Claim 46 (depends on 44) The apparatus of claim 44, wherein the indication of the duration of the LBT procedure is included in the uplink grant or transmitted together with the uplink grant. ### Claim 47 (depends on 44) The apparatus of claim 44, wherein the duration of the LBT procedure is synchronized with a frame boundary, a slot boundary, or a symbol boundary of a frame structure used for communications between the UE and the base station. ### Claim 48 (depends on 44) The apparatus of claim 44, wherein the UE is a first UE, and wherein the instructions are further executable by the processor to cause the apparatus to: determine that a second uplink transmission of a second UE has a second duration that is less than the duration of the LBT procedure of the first UE; schedule the second uplink transmission of the second UE within the duration of the LBT procedure of the first UE; and transmit a second uplink grant to the second UE. ### Claim 49 (depends on 48) The apparatus of claim 48, wherein the instructions are further executable by the processor to cause the apparatus to: determine an offset value between the uplink grant and a start of the LBT procedure at the first UE based at least in part on a duration of the second uplink transmission of the second UE; and indicate the offset value to the first UE. ### Claim 50 (depends on 48) The apparatus of claim 48, wherein the second UE is selected based at least in part on a cross-UE interference between transmission beams of the first UE and the second UE being below a threshold value. ### Claim 51 (depends on 43) The apparatus of claim 43, wherein the instructions are further executable by the processor to cause the apparatus to: transmit a second uplink grant to a different UE during a duration of the LBT procedure. ### Claim 52 (depends on 43) The apparatus of claim 43, wherein the uplink grant is a short control signaling transmission that is exempt from the LBT procedure. ### Claim 53 (depends on 43) The apparatus of claim 43, wherein the instructions are further executable by the processor to cause the apparatus to: determine that the uplink transmission is not received; and reuse the granted resource for transmission or reception for one or more different UEs. ### Claim 54 (depends on 43) The apparatus of claim 43, wherein the uplink grant is transmitted to the UE during a downlink transmission of a previous channel occupancy time (COT) or transmission opportunity (TxOP). ### Claim 55 (depends on 54) The apparatus of claim 54, wherein the uplink grant further indicates an ending time of the previous COT or TxOP, and wherein the UE initiates the LBT procedure after the ending time of the previous COT or TxOP. ### Claim 56 (depends on 54) The apparatus of claim 54, wherein the uplink grant is transmitted from the base station before an end of the downlink transmission of downlink shared channel data. ### Claim 57 (depends on 43) The apparatus of claim 43, wherein at least a portion of a duration of the LBT procedure overlaps with a portion of the previous COT or TxOP. ### Claim 58 (depends on 43) The apparatus of claim 43, wherein one or more of the uplink grant or uplink transmission are transmitted via a beamformed transmission beam. ### Claim 59 An apparatus for wireless communication at a user equipment (UE), comprising: means for receiving an uplink grant from a base station that indicates uplink resources for transmission of uplink data from the UE to the base station in a shared millimeter wave (mmW) radio frequency spectrum band; means for performing, responsive to receiving the uplink grant, a listen-before-talk (LBT) procedure to determine that the shared mmW radio frequency spectrum band is available for the transmission of the uplink data; and means for transmitting, based at least in part on the shared mmW radio frequency spectrum band being available for the transmission of the uplink data, the uplink data to the base station using the uplink resources indicated in the uplink grant. ### Claim 60 An apparatus for wireless communication at a base station, comprising: means for allocating uplink resources to a user equipment (UE) for an uplink transmission of uplink data from the UE to the base station in a shared millimeter wave (mmW) radio frequency spectrum band; means for transmitting an uplink grant to the UE indicating the uplink resources; and means for monitoring for the uplink transmission from the UE using the uplink resources indicated in the uplink grant, wherein the UE is to perform a listen-before-talk (LBT) procedure prior to the uplink transmission. ### Claim 61 A non-transitory computer-readable medium storing code for wireless communication at a user equipment (UE), the code comprising instructions executable by a processor to: receive an uplink grant from a base station that indicates uplink resources for transmission of uplink data from the UE to the base station in a shared millimeter wave (mmW) radio frequency spectrum band; perform, responsive to receiving the uplink grant, a listen-before-talk (LBT) procedure to determine that the shared mmW radio frequency spectrum band is available for the transmission of the uplink data; and transmit, based at least in part on the shared mmW radio frequency spectrum band being available for the transmission of the uplink data, the uplink data to the base station using the uplink resources indicated in the uplink grant. ### Claim 62 A non-transitory computer-readable medium storing code for wireless communication at a base station, the code comprising instructions executable by a processor to: allocate uplink resources to a user equipment (UE) for an uplink transmission of uplink data from the UE to the base station in a shared millimeter wave (mmW) radio frequency spectrum band; transmit an uplink grant to the UE indicating the uplink resources; and monitor for the uplink transmission from the UE using the uplink resources indicated in the uplink grant, wherein the UE is to perform a listen-before-talk (LBT) procedure prior to the uplink transmission.