# US 11,909,691 B2 · On-demand negative acknowledgment resource request > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,909,691 B2 - Document ID: US11909691B2 - Status: Granted - Kind: B2 - Application number: 17/518,167 - Filed: 2021-11-03 - Published: 2022-05-12 - Granted: 2024-02-20 - Earliest claimed: 2020-11-06 - Assignees: QUALCOMM Incorporated - Applicants: QUALCOMM Incorporated - Inventors: Qian Zhang; Yan Zhou; Tao Luo; Junyi Li - Web page: https://patentgrep.com/patent/US11909691B2 ## CPC - H04L 5/0055: {Physical resource allocation for ACK/NACK (for physical mapping arrangements in ARQ protocols H04L1/1861)} - H04L 1/1861: {Physical mapping arrangements (for ACK signaling see also H04L5/0053)} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract Methods, systems, and devices for wireless communications are described. Generally, the described techniques provide for reducing the overhead associated with reporting feedback, such as hybrid automatic repeat request (HARQ) feedback. A user equipment (UE) may receive a configuration message from a base station indicating that the UE is to request resources for transmitting negative acknowledgment (NACK) feedback for a downlink transmission. If the UE fails to receive or decode the downlink transmission, the UE may request resources from the base station on which to transmit the NACK feedback for the downlink transmission. Because the UE may be configured to request resources on which to transmit the NACK feedback, the UE may avoid transmitting HARQ feedback for every downlink transmission from the base station. Thus, the base station may avoid allocating resources for HARQ feedback from the UE for every downlink transmission, and the overhead of reporting HARQ feedback is reduced. ## Claims ### Claim 1 A method for wireless communication at a user equipment (UE), comprising: receiving, from a base station, a configuration message indicating that the UE is to request resources for transmitting negative acknowledgment feedback to the base station for a downlink transmission; attempting to decode the downlink transmission from the base station; determining to transmit the negative acknowledgment feedback to the base station for the downlink transmission based at least in part on receiving the configuration message and attempting to decode the downlink transmission; and transmitting, to the base station, a request for resources for transmitting the negative acknowledgment feedback based at least in part on determining to transmit the negative acknowledgment feedback. ### Claim 2 (depends on 1) The method of claim 1, further comprising: receiving, from the base station, an indication of resources allocated for transmitting the negative acknowledgment feedback based at least in part on transmitting the request for resources; and transmitting the negative acknowledgment feedback to the base station on the indicated resources. ### Claim 3 (depends on 1) The method of claim 1, wherein receiving the configuration message indicating that the UE is to request resources for transmitting the negative acknowledgment feedback to the base station comprises: receiving, in the configuration message, an indication of all or a subset of semi-persistent scheduling downlink transmissions for which the UE is to request resources for transmitting the negative acknowledgment feedback to the base station. ### Claim 4 (depends on 1) The method of claim 1, wherein receiving the configuration message indicating that the UE is to request resources for transmitting the negative acknowledgment feedback to the base station comprises: receiving, in the configuration message, an indication of all or a subset of downlink hybrid automatic repeat request identifiers associated with downlink transmissions for which the UE is to request resources for transmitting the negative acknowledgment feedback to the base station. ### Claim 5 (depends on 1) The method of claim 1, wherein receiving the configuration message indicating that the UE is to request resources for transmitting the negative acknowledgment feedback to the base station comprises: receiving, in the configuration message, an indication of one or more downlink control information scheduled downlink transmissions for which the UE is to request resources for transmitting the negative acknowledgment feedback to the base station. ### Claim 6 (depends on 1) The method of claim 1, wherein determining to transmit the negative acknowledgment feedback to the base station for the downlink transmission comprises: determining that an acknowledgment or negative acknowledgment codebook for the downlink transmission comprises at least one negative acknowledgment. ### Claim 7 (depends on 1) The method of claim 1, wherein determining to transmit the negative acknowledgment feedback to the base station for the downlink transmission comprises: determining that an acknowledgment or negative acknowledgment feedback bit for a hybrid automatic repeat request identifier corresponding to the downlink transmission comprises a negative acknowledgment. ### Claim 8 (depends on 1) The method of claim 1, wherein transmitting the request for resources for transmitting the negative acknowledgment feedback comprises: transmitting a scheduling request comprising the request for resources for transmitting the negative acknowledgment feedback. ### Claim 9 (depends on 1) The method of claim 1, wherein transmitting the request for resources for transmitting the negative acknowledgment feedback comprises: transmitting the request for resources for transmitting the negative acknowledgment feedback on an acknowledgment or negative acknowledgment feedback resource for a second downlink transmission. ### Claim 10 (depends on 1) The method of claim 1, wherein transmitting the request for resources for transmitting the negative acknowledgment feedback comprises: transmitting the request for resources for transmitting the negative acknowledgment feedback in uplink control information or a medium access control control element of an existing allocation. ### Claim 11 (depends on 1) The method of claim 1, wherein transmitting the request for resources for transmitting the negative acknowledgment feedback comprises: transmitting the request for resources for transmitting the negative acknowledgment feedback on dedicated resources for the request allocated to the UE or a group of UEs comprising the UE. ### Claim 12 (depends on 1) The method of claim 1, wherein transmitting the request for resources for transmitting the negative acknowledgment feedback comprises: transmitting the request for resources for transmitting the negative acknowledgment feedback on contention-based resources for the request. ### Claim 13 (depends on 1) The method of claim 1, further comprising: receiving an indication of resources or a message in which the UE is to transmit the request for resources for transmitting the negative acknowledgment feedback. ### Claim 14 (depends on 1) The method of claim 1, further comprising: transmitting the negative acknowledgment feedback associated with a corresponding acknowledgment or negative acknowledgment codebook or downlink hybrid automatic repeat request identifier containing at least one negative acknowledgment bit to the base station on resources allocated based at least in part on the request for resources. ### Claim 15 (depends on 1) The method of claim 1, wherein the configuration message is received in a radio resource control message, a medium access control control element, or a downlink control information message. ### Claim 16 A method for wireless communication at a base station, comprising: transmitting, to a user equipment (UE), a configuration message indicating that the UE is to request resources for transmitting negative acknowledgment feedback to the base station for a downlink transmission; transmitting the downlink transmission to the UE; receiving, from the UE based at least in part on transmitting the configuration message and on transmitting the downlink transmission, a request for resources to be used by the UE to transmit the negative acknowledgment feedback for the downlink transmission; and transmitting, to the UE based at least in part on receiving the request, an indication of resources allocated for transmitting the negative acknowledgment feedback. ### Claim 17 (depends on 16) The method of claim 16, further comprising: receiving the negative acknowledgment feedback from the UE on the indicated resources based at least in part on transmitting the indication of resources. ### Claim 18 (depends on 16) The method of claim 16, wherein transmitting the configuration message indicating that the UE is to request resources for transmitting the negative acknowledgment feedback to the base station comprises: transmitting, in the configuration message, an indication of all or a subset of semi-persistent scheduling downlink transmissions for which the UE is to request resources for transmitting the negative acknowledgment feedback to the base station. ### Claim 19 (depends on 16) The method of claim 16, wherein transmitting the configuration message indicating that the UE is to request resources for transmitting the negative acknowledgment feedback to the base station comprises: transmitting, in the configuration message, an indication of all or a subset of downlink hybrid automatic repeat request identifiers associated with downlink transmissions for which the UE is to request resources for transmitting the negative acknowledgment feedback to the base station. ### Claim 20 (depends on 16) The method of claim 16, wherein transmitting the configuration message indicating that the UE is to request resources for transmitting the negative acknowledgment feedback to the base station comprises: transmitting, in the configuration message, an indication of one or more downlink control information scheduled downlink transmissions for which the UE is to request resources for transmitting the negative acknowledgment feedback to the base station. ### Claim 21 (depends on 16) The method of claim 16, wherein receiving the request for resources to be used by the UE to transmit the negative acknowledgment feedback comprises: receiving a scheduling request comprising the request for resources to be used by the UE to transmit the negative acknowledgment feedback. ### Claim 22 (depends on 16) The method of claim 16, wherein receiving the request for resources to be used by the UE to transmit the negative acknowledgment feedback comprises: receiving the request for resources to be used by the UE to transmit the negative acknowledgment feedback on an acknowledgment or negative acknowledgment feedback resource for a second downlink transmission. ### Claim 23 (depends on 16) The method of claim 16, wherein receiving the request for resources to be used by the UE to transmit the negative acknowledgment feedback comprises: receiving the request for resources to be used by the UE to transmit the negative acknowledgment feedback in uplink control information or a medium access control control element of an existing allocation. ### Claim 24 (depends on 16) The method of claim 16, wherein receiving the request for resources to be used by the UE to transmit the negative acknowledgment feedback comprises: receiving the request for resources to be used by the UE to transmit the negative acknowledgment feedback on dedicated resources for the request allocated to the UE or a group of UEs including the UE. ### Claim 25 (depends on 16) The method of claim 16, wherein receiving the request for resources to be used by the UE to transmit the negative acknowledgment feedback comprises: receiving the request for resources to be used by the UE to transmit the negative acknowledgment feedback on contention-based resources for the request. ### Claim 26 (depends on 16) The method of claim 16, further comprising: transmitting a second indication of resources or a message in which the UE is to transmit the request for resources for transmitting the negative acknowledgment feedback. ### Claim 27 (depends on 16) The method of claim 16, further comprising: receiving the negative acknowledgment feedback associated with a corresponding acknowledgment or negative acknowledgment codebook or downlink hybrid automatic repeat request identifier containing at least one negative acknowledgment bit from the UE on resources allocated based at least in part on the request for resources. ### Claim 28 (depends on 16) The method of claim 16, wherein the configuration message is transmitted in a radio resource control message, a medium access control control element, or a downlink control information message. ### Claim 29 An apparatus for wireless communication at a user equipment (UE), comprising: a processor; a memory coupled with the processor, wherein the memory comprises instructions executable by the processor to cause the apparatus to: receive, from a base station, a configuration message indicating that the UE is to request resources for transmitting negative acknowledgment feedback to the base station for a downlink transmission; attempt to decode the downlink transmission from the base station; determine to transmit the negative acknowledgment feedback to the base station for the downlink transmission based at least in part on receiving the configuration message and attempting to decode the downlink transmission; and transmit, to the base station, a request for resources for transmitting the negative acknowledgment feedback based at least in part on determining to transmit the negative acknowledgment feedback. ### Claim 30 An apparatus for wireless communication at a base station, comprising: a processor; a memory coupled with the processor, wherein the memory comprises instructions executable by the processor to cause the apparatus to: transmit, to a user equipment (UE), a configuration message indicating that the UE is to request resources for transmitting negative acknowledgment feedback to the base station for a downlink transmission; transmit the downlink transmission to the UE; receive, from the UE based at least in part on transmitting the configuration message and on transmitting the downlink transmission, a request for resources to be used by the UE to transmit the negative acknowledgment feedback for the downlink transmission; and transmit, to the UE based at least in part on receiving the request, an indication of resources allocated for transmitting the negative acknowledgment feedback.