Abstract: Methods, systems, and devices for wireless communications are described for handling uplink grants that have associated uplink transmission that may exceed exposure limits. Exposure limits may be based on maximum permissible exposure (MPE) limits of millimeter wave transmissions and may be determined at a user equipment (UE) and provided to a base station. If the UE receives an uplink grant for a transmission in which an associated uplink transmission would exceed the exposure limits, the UE may drop the uplink transmission prior to forming a transport block, transmit control signaling to the base station to indicate the exposure limits at the UE, or combinations thereof.

Abstract: Methods, systems, and devices for wireless communications are described in which uplink timelines may be reduced by initiating, at a user equipment (UE), uplink transmission processing prior to receipt of an uplink grant for an uplink communication. A UE may identify one or more uplink transmission parameters associated with a reduced uplink transmission timeline for an uplink communication, and use the uplink transmission parameters to initiate processing of the uplink communication prior to receiving an uplink grant from a base station. The uplink transmission parameters may allow for packet preparation at a higher layers (e.g., at a medium access control (MAC) layer or radio link control (RLC) layer) to be started or completed prior to receipt of the uplink grant.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) may transmit a UE capability message, the UE capability message indicating a supported transmit antenna switching (TxAS) capability for each port of the UE. The UE may receive a configuration message indicating an uplink multiple-input/multiple-output (UL MIMO) configuration for the UE, the UL MIMO configuration being based at least in part on the UE capability message. The UE may identify, based at least in part on the configuration message, a sounding reference signal (SRS) configuration to use for transmitting SRSs in conjunction with the UL MIMO communications, the SRS configuration comprising a configuration for transmission by the UE of SRSs using at least one of the two or more ports of the UE, the SRSs transmitted on one or more antennas of the UE selected according to a TxAS configuration for the respective port.

Abstract: In an embodiment, a UE receives a first uplink grant for a first RAT (e.g., 5G NR) and a second uplink grant for a second RAT (e.g., LTE). In one embodiment, the UE schedules an uplink transmission on the first RAT (e.g., by selectively dropping the uplink transmission on particular resource blocks) so as to manage an amount of time that is based on concurrent uplink transmissions on both the first and second RATs are performed. In another embodiment, the UE establishes a first period of time where a BSR transmitted by the UE on the first RAT is adjusted based on scheduling of concurrent uplink multi-RAT transmissions, and a second period of time where no BSR is transmitted by the UE on the first RAT based where concurrent uplink transmissions on both the first and second RATs are not permitted to be scheduled.

Abstract: In an aspect, a UE determines whether there is an overlap between a first uplink transmission channel allocated for transmission of a first uplink transmission and a second uplink transmission channel allocated for transmission of second uplink transmission. The UE generates a combined uplink transmission payload in response to a determination that there is the overlap, wherein the combined uplink transmission payload includes at least a portion of the first uplink transmission and at least a portion of the second uplink transmission. The UE transmits the combined uplink transmission payload on either the first uplink transmission channel or the second uplink transmission channel. A base station receives the combined uplink transmission payload transmitted by the UE.

Abstract: A configurable new radio (NR) RACH procedure that may be executed by a UE and a base station is disclosed. A configuration to determine, by a user equipment, a random access procedure timeline, from multiple random access procedure timelines that each define a different duration between one or more messages that are communicated in a random access procedure can be determined or transmitted. A random access preamble can be received from the UE based on the random access procedure timeline, and a response to the random access preamble can be determined or transmitted based on the random access procedure timeline.

Abstract: A wireless device may identify a set of resources reserved for feedback information (e.g., resource elements (REs) reserved for feedback such as acknowledgement (ACK) or negative ACK (NACK) information) within a transmission time interval (TTI). Feedback information may be mapped to the reserved set of resources (e.g., reserved REs). The wireless device may determine a set of unused reserved resources (e.g., a set of unused reserved REs) based on the number of feedback bits. The wireless device may then map other bits (e.g., zeros, known bits, pattern or sequence of bits, random bits, etc.) to the set of unused reserved REs, or boost transmission power of bits mapped around the unused reserved REs. In some cases, the number of reserved REs may be determined based on the number of feedback bits (e.g., the size of the ACK/NACK payload). The wireless device may then transmit the information to a base station.

Abstract: Methods, systems, and devices for wireless communications are described for determination of sounding reference signal (SRS) parameters when multiple SRS resource sets are configured for a same SRS transmission resource. A user equipment (UE) may select one SRS resource set for a SRS transmission based on a prioritization of different SRS resource sets. In some cases, different SRS resource sets may be associated with different SRS usage parameters that indicate a use case for the SRS, and the UE may transmit a joint SRS for two or more SRS resource sets for predetermined combinations of SRS usage parameters. A base station that receives the SRS transmission may measure one or more channel parameters of the SRS and determine one or more settings for subsequent communications with the UE.

Abstract: Methods, systems, and devices for wireless communications are described for handling uplink grants that have associated uplink transmission that may exceed exposure limits. Exposure limits may be based on maximum permissible exposure (MPE) limits of millimeter wave transmissions and may be determined at a user equipment (UE) and provided to a base station. If the UE receives an uplink grant for a transmission in which an associated uplink transmission would exceed the exposure limits, the UE may drop the uplink transmission prior to forming a transport block, transmit control signaling to the base station to indicate the exposure limits at the UE, or combinations thereof.

Abstract: Methods, systems, and devices for wireless communications are described. The described techniques provide for selecting a PRACH occasion (RO) based on downlink quality, access congestion, latency (e.g., time to next available RO), beam correspondence, random access in previous transmissions, or combinations of these factors. The user equipment (UE) may detect access congestion of synchronization signal blocks (SSBs) and select the less congested SSB in the RO selection. The UE may detect the access congestion by receiving a back-off indicator from the base station, detecting a contention resolution failure, or the number or media access control (MAC) subheaders in a random access response. In some cases, the ROs associated with different SSBs have different latencies and the UE may select the earliest available RO.

Abstract: Methods, systems, and devices are described for handling transmissions or channels in wireless communications that collide with one another. The described techniques relate to handling the collision between multiple overlapping channels (e.g., two or more channels of the same priority). For example, a collision resolution configuration may include resolving the collisions among the channels of the same priority first (e.g., feedback information transmissions first, and then control information), among the channels of the same service type first (e.g., normal channels first, and then low latency channel(s)), or across all of the channels of all priorities at once.

Abstract: Certain aspects of the present disclosure relate to communication systems, and more particularly, to interpreting a timing advance (TA) command for members of a timing advance group (TAG), such as different uplink component carriers and/or different bandwidth parts, having different numerologies, such as different subarrier spacing (SCS). A method that may be performed by a user equipment (UE) includes receiving, from a base station (BS), a TA command. The UE interprets the TA command differently for different members of a same TAG, associated with different numerologies. The UE applies a timing adjustment when transmitting an uplink transmission to the BS based, at least in part, on the interpretation.

Abstract: A configurable new radio (NR) RACH procedure that may be executed by a UE and a base station is disclosed. A first message can be transmitted, in an inactive or idle state, a on a physical random access channel, where the first message includes a random access preamble. A second message can be received on a downlink channel in response to the first message, where the second message includes a temporary cell radio network temporary identifier and an uplink grant for the user equipment. A request can be transmitted on an uplink channel based on the uplink grant. A common search space of a downlink control channel can be monitored, such as for an acknowledgement message or a negative acknowledgement message corresponding to the request and identifiable based on the temporary cell radio network temporary identifier.

Abstract: The present disclosure relates to methods and devices for communication which may include a user equipment (UE) and a base station. In one aspect, the UE may receive a trigger to measure an uplink Aperiodic Channel State Information Reference Signal (A-CSI-RS). The UE may also receive an allocation of a first resource for an uplink shared channel. Additionally, the UE can receive at least one indication for an A-CSI report to comprise a null A-CSI report. Moreover, the UE can determine whether to alter another uplink transmission. In some aspects, this determination can be based, at least in part, on whether the first resource allocated for the uplink channel overlaps in time with a second resource for the other uplink transmission.

Abstract: Certain aspects of the present disclosure relate to methods and apparatus relating to multiplexing UCI with data in a physical uplink shared channel (PUSCH) transmission.

Abstract: Certain aspects of the present disclosure relate to uplink preemption in certain systems, such as new radio (NR) systems, supporting carrier aggregation (CA) and/or multi-connectivity modes. A method for wireless communication, that can be performed by a user equipment (UE), generally includes receiving a resource assignment scheduling the UE for uplink transmission. The UE receives an indication to preempt uplink transmission on a portion of the assigned resources and determines whether to transmit on the remaining assigned resources. A method that can be performed by a base station (BS) generally includes receiving an indication from one or more UEs indicating, for each of a plurality of band combinations, a capability of the UE to transmit on a band when transmission on another band in the band combination is preempted and scheduling the one or more UEs for uplink transmission based on the indication.

Abstract: Certain aspects of the present disclosure provide techniques for uplink preemption indication. A method for wireless communication by a user equipment (UE) includes receiving at least one ULPI from a base station (BS) indicating, for each of a plurality of sets of uplink resources, a power level the UE can use for one or more uplink transmissions. The UE can determine one or more power levels indicated by the ULPI for resources allocated for the UE for uplink transmission. The allocated resources may include multiple of the sets of uplink resources. The UE can select the power level to use for uplink transmission using the allocated resources based, at least in part, on the determination. The UE sends or drops the one or more uplink transmissions according to the ULPI. A time duration of the plurality of sets of uplink resources can be longer than a configured ULPI monitoring periodicity.

Abstract: Certain aspects of the present disclosure provide techniques for time division duplex configuration override. A method that may be performed by a user equipment (UE) includes detecting a period during which a configuration of a first radio access technology (RAT) conflicts with a configuration of a second RAT for a frequency band; and overriding the configuration of the second RAT with the configuration of the first RAT for the period.

Abstract: Certain aspects of the present disclosure relate to communication systems, and more particularly, to interpreting a timing advance (TA) command for members of a timing advance group (TAG), such as different uplink component carriers and/or different bandwidth parts, having different numerologies, such as different subcarrier spacing (SCS). A method that may be performed by a user equipment (UE) includes receiving, from a base station (BS), a TA command. The UE interprets the TA command differently for different members of a same TAG, associated with different numerologies. The UE applies a timing adjustment when transmitting an uplink transmission to the BS based, at least in part, on the interpretation.

Abstract: This disclosure relates to random access channel (RACH) enhancements for new radio unlicensed (NR-U) communications. Specifically, the present aspects include determining whether a gap length between a two-step random access channel (RACH) preamble transmission and a physical uplink shared channel (PUSCH) transmission satisfies a gap condition. The present aspects further include selecting a transmission procedure associated with the determined gap length for the PUSCH transmission. The present aspects further include performing the PUSCH transmission in accordance with the selected transmission procedure.