# US 2018/0324771 A1 · Sounding reference signal configuration and transport block size scaling in low latency systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0324771 A1 - Document ID: US20180324771A1 - Status: Published application - Kind: A1 - Application number: 15/969,586 - Filed: 2018-05-02 - Published: 2018-11-08 - Earliest claimed: 2017-05-05 - Assignees: QUALCOMM Incorporated - Applicants: QUALCOMM Incorporated - Inventors: Seyedkianoush Hosseini; Wanshi Chen; Shimman Arvind Patel; Peter Gaal - Web page: https://patentgrep.com/patent/US20180324771A1 ## CPC - H04W 72/23: in the downlink direction of a wireless link, i.e. towards a terminal - H04L 5/0048: {Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091)} - H04L 5/0051: {of dedicated pilots, i.e. pilots destined for a single user or terminal} - H04L 5/0092: {Indication of how the channel is divided} - H04W 52/146: {Uplink power control} - H04W 52/322: {Power control of broadcast channels} - H04W 52/325: {Power control of control or pilot channels} - H04W 72/0446: Resources in time domain, e.g. slots or frames - H04L 25/0226: {sounding signals per se} - H04W 52/10: Open loop power control - H04W 52/367: {Power values between minimum and maximum limits, e.g. dynamic range} - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract Methods, systems, and devices for wireless communication are described. A base station may transmit an indication of first and second configurations for sounding reference signal (SRS) transmissions during first and second transmission time intervals (TTIs) having different durations. A user equipment (UE) may identify an SRS to be transmitted and determine a configuration for the SRS transmission based on the TTI duration and the received indication of the first and second configurations. The UE may then transmit the SRS based on the configuration. A base station may receive an SRS during a TTI and may determine a channel quality based at least in part on the SRS. Additionally, a device may identify data to transmit during a TTI, determine a number of resource elements available for transmission of the data during a TTI, and determine a transport block size (TBS) for the data transmission based on the available resource elements. ## Claims ### Claim 1 A method for wireless communication in a system that supports a first transmission time interval (TTI) duration and a second TTI duration that is greater than the first TTI duration, comprising: receiving a grant in downlink control information (DCI) or shortened DCI (sDCI); identifying a sounding reference signal (SRS) to be transmitted based at least in part on receiving the grant; determining a configuration for the SRS based at least in part on the grant being received in the DCI or the sDCI; and transmitting the SRS during a TTI having the first TTI duration or a TTI having the second TTI duration based at least in part on the configuration. ### Claim 2 (depends on 1) The method of claim 1, wherein determining the configuration for the SRS based at least in part on the grant being received in the DCI or the sDCI comprises: determining the configuration for the SRS based at least in part on the SRS being scheduled to be transmitted in the TTI having the first TTI duration or the TTI having the second TTI duration. ### Claim 3 (depends on 1) The method of claim 1, further comprising: receiving an indication of a first configuration for SRS transmissions during TTIs having the first TTI duration and an indication of a second configuration for SRS transmissions during TTIs having the second TTI duration, wherein the configuration for the SRS is determined based at least in part on the received indications. ### Claim 4 (depends on 3) The method of claim 3, wherein determining the configuration for the SRS comprises: determining a transmit power configuration for the SRS according to the first configuration when the SRS is scheduled to be transmitted in the TTI having the first TTI duration and according to the second configuration when the SRS is scheduled to be transmitted in the TTI having the second TTI duration. ### Claim 5 (depends on 4) The method of claim 4, wherein determining the transmit power configuration for the SRS comprises: receiving one or more open-loop power parameters corresponding to the SRS being scheduled to be transmitted in the TTI having the first TTI duration or the TTI having the second TTI duration; and selecting a closed-loop parameter corresponding to the SRS being scheduled to be transmitted in the TTI having the first TTI duration or the TTI having the second TTI duration. ### Claim 6 (depends on 5) The method of claim 5, wherein the closed-loop power parameter is a power control adjustment state corresponding to the SRS being scheduled to be transmitted in the TTI having the first TTI duration or the TTI having the second TTI duration. ### Claim 7 (depends on 5) The method of claim 5, wherein the one or more open-loop power parameters comprise: a maximum transmit power, an SRS offset, or a bandwidth used to transmit the SRS, or a combination thereof, corresponding to the SRS being scheduled to be transmitted in the TTI having the first TTI duration or the TTI having the second TTI duration. ### Claim 8 (depends on 1) The method of claim 1, wherein receiving the grant in DCI or sDCI comprises: receiving the grant in sDCI, wherein the SRS is transmitted according to the configuration corresponding to the TTI having the first TTI duration based at least in part on receiving the grant in sDCI. ### Claim 9 (depends on 1) The method of claim 1, wherein receiving the grant in DCI or sDCI comprises: receiving the grant in DCI, wherein the SRS is transmitted according to the configuration corresponding to the TTI having the second TTI duration based at least in part on receiving the grant in DCI. ### Claim 10 (depends on 1) The method of claim 1, further comprising: receiving multiple transmit power configurations during multiple TTIs for the SRS to be transmitted during the TTI having the first TTI duration or the TTI having the second TTI duration; and determining the configuration for the SRS based at least in part on one or more of the multiple transmit power configurations. ### Claim 11 (depends on 10) The method of claim 10, wherein determining the configuration for the SRS based at least in part on one or more of the multiple transmit power configurations comprises: determining the configuration for the SRS based at least in part on an accumulation of the multiple transmit power configurations. ### Claim 12 (depends on 10) The method of claim 10, wherein determining the configuration for the SRS based at least in part on one or more of the multiple transmit power configurations comprises: determining the configuration for the SRS based at least in part on a highest or lowest transmit power indicated in one of the multiple transmit power configurations. ### Claim 13 (depends on 10) The method of claim 10, wherein determining the configuration for the SRS based at least in part on one or more of the multiple transmit power configurations comprises: determining the configuration for the SRS based at least in part on an average of transmit powers indicated in the multiple transmit power configurations. ### Claim 14 (depends on 10) The method of claim 10, wherein the multiple transmit power configurations indicate a same transmit power configuration to be used to transmit the SRS. ### Claim 15 (depends on 1) The method of claim 1, further comprising: identifying a collision between a first SRS transmission during a first TTI having the first TTI duration and a second SRS transmission during a second TTI having the second TTI duration. ### Claim 16 (depends on 15) The method of claim 15, wherein the first SRS transmission and the second SRS transmission are scheduled on a same carrier or on different carriers. ### Claim 17 (depends on 15) The method of claim 15, wherein the configuration indicates a first priority for SRS transmissions during TTIs having the first TTI duration and a second priority for SRS transmissions during TTIs having the second TTI duration. ### Claim 18 (depends on 17) The method of claim 17, further comprising: determining whether to transmit the first SRS, the second SRS, or both based at least in part on comparing the first priority to the second priority. ### Claim 19 (depends on 18) The method of claim 18, wherein determining whether to transmit the first SRS, the second SRS, or both comprises: determining whether to transmit the first SRS, the second SRS, or both based at least in part on a power constraint. ### Claim 20 (depends on 18) The method of claim 18, wherein determining whether to transmit the first SRS, the second SRS, or both comprises: determining whether to transmit the first SRS, the second SRS, or both based at least in part on whether a first bandwidth associated with the first SRS overlaps with a second bandwidth associated with the second SRS. ### Claim 21 (depends on 15) The method of claim 15, further comprising: transmitting the first SRS and the second SRS simultaneously. ### Claim 22 (depends on 15) The method of claim 15, further comprising: refraining from transmitting the first SRS and the second SRS. ### Claim 23 A method for wireless communication in a system that supports a first transmission time interval (TTI) duration and a second TTI duration that is greater than the first TTI duration, comprising: transmitting an indication of a first configuration for sounding reference signal (SRS) transmissions during TTIs having the first TTI duration and an indication of a second configuration for SRS transmissions during TTIs having the second TTI duration; receiving an SRS during a TTI, wherein a configuration of the SRS is based at least in part on either the first configuration or the second configuration; and determining at least a channel quality of a channel used to transmit data during the TTI based at least in part on the SRS. ### Claim 24 (depends on 23) The method of claim 23, wherein transmitting the indication of the first configuration and the indication of the second configuration comprises: transmitting one or more open-loop power parameters corresponding to the TTI having either the first TTI duration or the second TTI duration. ### Claim 25 (depends on 24) The method of claim 24, wherein the one or more open-loop power parameters comprise a maximum transmit power, an SRS offset, or a bandwidth used to transmit the SRS, or a combination thereof corresponding to the TTI having either the first TTI duration or the second TTI duration. ### Claim 26 (depends on 23) The method of claim 23, wherein the SRS comprises an aperiodic SRS. ### Claim 27 (depends on 26) The method of claim 26, further comprising: transmitting a grant in shortened downlink control information (DCI), wherein the SRS is received according to the first configuration during the TTI having the first TTI duration based at least in part on the transmitted grant. ### Claim 28 (depends on 26) The method of claim 26, further comprising: transmitting a grant in downlink control information (DCI), wherein the SRS is received according to the second configuration during the TTI having the second TTI duration based at least in part on the transmitted grant. ### Claim 29 A method for wireless communication in a system that supports a first transmission time interval (TTI) duration and a second TTI duration that is greater than the first TTI duration, comprising: identifying data to transmit during a TTI having the first TTI duration; determining a number of resource elements available for transmission of the data during the TTI having the first TTI duration; and determining a transport block size (TBS) for transmission of the data during the TTI having the first TTI duration based at least in part on the determined number of resource elements available for transmission of the data during the TTI having the first TTI duration. ### Claim 30 (depends on 29) The method of claim 29, wherein determining the number of resource elements available for transmission of the data during the TTI having the first TTI duration comprises: identifying a number of resource elements within the TTI having the first TTI duration that are reserved for control information in a control channel associated with communications during a TTI having the second TTI duration. ### Claim 31 (depends on 30) The method of claim 30, wherein identifying the number of resource elements within the TTI having the first TTI duration that are reserved for control information comprises: identifying a default number of resource elements within the TTI having the first TTI duration that are reserved for control information. ### Claim 32 (depends on 30) The method of claim 30, wherein the control channel comprises a physical downlink control channel (PDCCH). ### Claim 33 (depends on 29) The method of claim 29, wherein determining a number of resource elements available for transmission of the data during the TTI having the first TTI duration comprises: identifying a number of resource elements within the TTI having the first TTI duration that are reserved for control information in a control channel associated with communications during a TTI having the first TTI duration. ### Claim 34 (depends on 33) The method of claim 33, wherein the control channel comprises a shortened physical downlink control channel (sPDCCH). ### Claim 35 (depends on 29) The method of claim 29, further comprising: determining whether a transmission mode (TM) used for communication during the TTI having the first TTI duration is cell-specific reference signal (CRS)-based or demodulation reference signal (DMRS)-based; and determining the TBS for the transmission based at least in part on determining whether the TM is CRS-based or DMRS-based. ### Claim 36 An apparatus for wireless communication in a system that supports a first transmission time interval (TTI) duration and a second TTI duration that is greater than the first TTI duration, comprising: means for receiving a grant in downlink control information (DCI) or shortened DCI (sDCI); means for identifying a sounding reference signal (SRS) to be transmitted based at least in part on receiving the grant; means for determining a configuration for the SRS based at least in part on the grant being received in the DCI or the sDCI; and means for transmitting the SRS during a TTI having the first TTI duration or a TTI having the second TTI duration based at least in part on the configuration. ### Claim 37 An apparatus for wireless communication in a system that supports a first transmission time interval (TTI) duration and a second TTI duration that is greater than the first TTI duration, comprising: means for transmitting an indication of a first configuration for sounding reference signal (SRS) transmissions during TTIs having the first TTI duration and an indication of a second configuration for SRS transmissions during TTIs having the second TTI duration; means for receiving an SRS during a TTI, wherein a configuration of the SRS is based at least in part on either the first configuration or the second configuration; and means for determining at least a channel quality of a channel used to transmit data during the TTI based at least in part on the SRS. ### Claim 38 An apparatus for wireless communication in a system that supports a first transmission time interval (TTI) duration and a second TTI duration that is greater than the first TTI duration, comprising: means for identifying data to transmit during a TTI having the first TTI duration; means for determining a number of resource elements available for transmission of the data during the TTI having the first TTI duration; and means for determining a transport block size (TBS) for transmission of the data during the TTI having the first TTI duration based at least in part on the determined number of resource elements available for transmission of the data during the TTI having the first TTI duration. ### Claim 39 A mobile device for wireless communication in a system that supports a first transmission time interval (TTI) duration and a second TTI duration that is greater than the first TTI duration, comprising: a processor; memory in electronic communication with the processor; and instructions stored in the memory and operable, when executed by the processor, to cause the apparatus to: receive a grant in downlink control information (DCI) or shortened DCI (sDCI); identify a sounding reference signal (SRS) to be transmitted based at least in part on receiving the grant; determine a configuration for the SRS based at least in part on the grant being received in the DCI or the sDCI; and transmit the SRS during a TTI having the first TTI duration or a TTI having the second TTI duration based at least in part on the configuration. ### Claim 40 A network device for wireless communication in a system that supports a first transmission time interval (TTI) duration and a second TTI duration that is greater than the first TTI duration, comprising: a processor; memory in electronic communication with the processor; and instructions stored in the memory and operable, when executed by the processor, to cause the apparatus to: transmit an indication of a first configuration for sounding reference signal (SRS) transmissions during TTIs having the first TTI duration and an indication of a second configuration for SRS transmissions during TTIs having the second TTI duration; receive an SRS during a TTI, wherein a configuration of the SRS is based at least in part on either the first configuration or the second configuration; and determine at least a channel quality of a channel used to transmit data during the TTI based at least in part on the SRS. ### Claim 41 An apparatus for wireless communication in a system that supports a first transmission time interval (TTI) duration and a second TTI duration that is greater than the first TTI duration, comprising: a processor; memory in electronic communication with the processor; and instructions stored in the memory and operable, when executed by the processor, to cause the apparatus to: identify data to transmit during a TTI having the first TTI duration; determine a number of resource elements available for transmission of the data during the TTI having the first TTI duration; and determine a transport block size (TBS) for transmission of the data during the TTI having the first TTI duration based at least in part on the determined number of resource elements available for transmission of the data during the TTI having the first TTI duration. ### Claim 42 A non-transitory computer readable medium storing code for wireless communication in a system that supports a first transmission time interval (TTI) duration and a second TTI duration that is greater than the first TTI duration, the code comprising instructions executable by a processor to: receive a grant in downlink control information (DCI) or shortened DCI (sDCI); identify a sounding reference signal (SRS) to be transmitted based at least in part on receiving the grant; determine a configuration for the SRS based at least in part on the grant being received in the DCI or the sDCI; and transmit the SRS during a TTI having the first TTI duration or a TTI having the second TTI duration based at least in part on the configuration. ### Claim 43 A non-transitory computer readable medium storing code for wireless communication in a system that supports a first transmission time interval (TTI) duration and a second TTI duration that is greater than the first TTI duration, the code comprising instructions executable by a processor to: transmit an indication of a first configuration for sounding reference signal (SRS) transmissions during TTIs having the first TTI duration and an indication of a second configuration for SRS transmissions during TTIs having the second TTI duration; receive an SRS during a TTI, wherein a configuration of the SRS is based at least in part on either the first configuration or the second configuration; and determine at least a channel quality of a channel used to transmit data during the TTI based at least in part on the SRS. ### Claim 44 A non-transitory computer readable medium storing code for wireless communication in a system that supports a first transmission time interval (TTI) duration and a second TTI duration that is greater than the first TTI duration, the code comprising instructions executable by a processor to: identify data to transmit during a TTI having the first TTI duration; determine a number of resource elements available for transmission of the data during the TTI having the first TTI duration; and determine a transport block size (TBS) for transmission of the data during the TTI having the first TTI duration based at least in part on the determined number of resource elements available for transmission of the data during the TTI having the first TTI duration.