Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) may transmit, and a network entity may receive, multiple physical random access channel (PRACH) signals at multiple power levels during a time period. The multiple power levels may be randomly or pseudo-randomly selected from within a power range defined for the PRACH signals. The UE may receive a response message indicating one or more of the PRACH signals of the multiple PRACH signals detected during the time period. The UE may transmit a random access request message at a first power level of the multiple power levels according to the one or more PRACH signals of the multiple PRACH signals detected during the time period.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) may receive encoded data from a network entity. The UE may decode the data in accordance with a size of the circular buffer. The UE, the network entity, or both may determine the size of the circular buffer based on a capability of the UE. In some examples, the size of the circular buffer may be associated with one or more limits for performing the decoding operation, including a limit for a quantity of encoded bits the UE can process during a sliding window. For example, the limits may consider any combination of a quantity of encoded bits or information bits that the UE may write to or write from a memory of the UE. In some cases, the limits may consider multiple bandwidth parts, multiple component carriers, or any combination thereof.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) may receive configuration information indicating a sidelink resource pool, a time gap, and a periodicity of feedback occasions. The UE may generate feedback bits associated with multiple received sidelink messages based on the configuration information. The UE may transmit the feedback bits in a single, multi-bit feedback message according to one or more rules. In some examples, the UE may drop one or more sets of feedback bits (e.g., in the case of a collision of too many feedback messages in a single slot) based on a weighted average priority level of one or more valid feedback bits in each of multiple sets of feedback bits.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive configuration information indicating a power offset, per resource block, between one or more first resource blocks to carry acknowledgement/negative acknowledgement feedback and one or more second resource blocks in a common interlace. The UE may transmit, using the power offset and using a transmission power that depends on whether a downlink pathloss value is indicated in the configuration information, a physical sidelink feedback channel transmission in the one or more first resource blocks and the one or more second resource blocks. Numerous other aspects are described.

Abstract: Disclosed are techniques for environment sensing. In an aspect, a transmitter base station determines a configuration for a radio frequency (RF) sensing signal, the configuration determined based at least in part on coordination among a plurality of base stations, and transmits the RF sensing signal to at least one receiver base station based on the configuration. In an aspect, a receiver base station receives a configuration for an RF sensing signal, the configuration determined based at least in part on coordination among a plurality of base stations, receives, from at least one transmitter base station, the RF sensing signal, and detects at least one target object based, at least in part, on reception of the RF sensing signal.

Abstract: This disclosure provides systems, methods and apparatus, including computer programs encoded on computer storage media, for maintaining, between a user equipment (UE) and a component of a base station (BS), a mutual understanding of a set of linked physical downlink control channel (PDCCH) candidates if the UE selects to monitor a subset of the linked PDCCH candidates. In one aspect, the UE may monitor the subset of the linked PDCCH candidates, and the UE and the component of the BS may select a reference PDCCH candidate from which to define scheduling information in accordance with the UE monitoring the subset of the linked PDCCH candidates. In some examples, the UE and the component of the BS may select the reference PDCCH candidate in accordance with one or more mutually understood rules or procedures such that the UE and the component of the BS may select a same reference PDCCH candidate.

Abstract: Lossless compression for HARQ-ACK codebooks with different BLER is described. An apparatus is configured to receive downlink transmission(s) from a network node. The apparatus is configured to transmit two-part HARQ-ACK feedback for the downlink transmission(s) based on: a first compression data set for a first HARQ-ACK codebook and a second compression data set for a second HARQ-ACK codebook, and/or a third compression data set based on a combination of the first and second HARQ-ACK codebooks. Another apparatus is configured to configure a UE with a first configuration for a first compression data set, a second compression data set, or a third compression data set, or a second configuration for a first rate, a second rate, or a third rate. The apparatus is configured to receive two-part HARQ-ACK feedback for a downlink transmission(s) based on the first and second compression data sets or the third compression data set.

Abstract: Wireless communications systems and methods related to use of cyclic prefix (CP) extensions for channel occupancy time (COT) sharing among sidelink user equipment devices (UEs) are provided. A first UE detects a first sidelink transmission in a COT, the COT for sharing with multiple sidelink UEs including the first sidelink UE. The first UE may determine a CP extension length for transmitting a second sidelink transmission after the first sidelink transmission, where a gap duration between the first sidelink transmission and the second sidelink transmission satisfies a listen-before-talk (LBT) gap time threshold. The first UE may apply a CP extension having the CP extension length to the second sidelink transmission and transmit, to a second sidelink UE, the second sidelink transmission with the CP extension.

Abstract: This disclosure provides systems, methods, and apparatus, including computer programs encoded on computer storage media, for multiple downlink control information (DCI) message handling for multiple control resource set (CORESET) groups. In one aspect, a user equipment (UE) may provide separate or joint feedback for data messages received from different CORESET groups. In some examples, the UE may be configured with code block group (CBG)-based transmissions for a component carrier (CC) or a CORESET group in a CC. If implementing a dynamic codebook, the UE may track separate transport block (TB)-based and CBG-based downlink assignment indexes (DAIs) for each CORESET group or may track joint TB-based and CBG-based DAIs across the set of CORESET groups to handle the CBG configuration. Additionally, or alternatively, if implementing a semi-static codebook, the UE may apply skipping rules across the set of CORESET groups or separately for each CORESET group to reduce signaling overhead.

Abstract: Methods, systems, and devices for wireless communications are described. Generally, a user equipment (UE) may transmit feedback signaling for received sidelink messages to both the base station and the transmitting UE. The receiving UE may multicast a feedback message to both the base station and the transmitting UE on a physical uplink control channel (PUCCH) or on a physical sidelink feedback channel (PSFCH). The base station may configure the receiving UE with resources, the transmitting UE may allocate resources to the receiving UE, or the base station may actively monitor for the feedback message. In some examples, the receiving UE may operate in a dual connectivity mode, and may transmit the feedback message to both the base station and the transmitting UE on both the PUCCH and the PSFCH.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a receiver may receive, from two or more transmitters, two or more sidelink control informations (SCIs) that schedule channel occupancy time (COT) resources for the two or more transmitters. The receiver may transmit, to a transmitter of the two or more transmitters, an acknowledgement or negative acknowledgement (A/N) feedback via a mini-slot carrying a physical sidelink feedback channel (PSFCH) or sidelink feedback information (SLFI) with SCI. The A/N feedback may be transmitted before a listen-before-talk (LBT) and physical sidelink shared channel (PSSCH) transmission. The receiver may receive, from the transmitter using a COT resource, the PSSCH transmission based at least in part on the A/N feedback. The LBT and the PSSCH transmission may be adjustable at the transmitter based at least in part on the A/N feedback. Numerous other aspects are described.

Abstract: This disclosure provides systems, methods, and devices for wireless communication that support management of network-configured sensing bandwidths in a wireless communication system. In particular aspects, a network configures a sensing bandwidth, and the sensing bandwidth configuration is signaled to a contending node. The contending node (e.g., a UE or a base station) performs a medium sensing procedure (e.g., a listen-before-talk (LBT) procedure) using the signaled configuration of the sensing bandwidth. Aspects of this disclosure provide various techniques for signaling the configuration of the sensing bandwidth to the contending node.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) and a base station may communicate in an unlicensed spectrum (e.g., a shared radio frequency spectrum band). As such, the UE may determine a codebook size for transmitting hybrid access request (HARQ) acknowledgement (ACK) feedback with respect to the unlicensed spectrum. Accordingly, the UE may base the HARQ ACK codebook size on a number of HARQ processes with which the UE has been configured. Additionally or alternatively, the UE may base the HARQ ACK codebook size on a number and/or duration of downlink channel monitoring occasions indicated by the base station. In some cases, the UE may base the HARQ ACK codebook size on a combination of the techniques described herein.

Abstract: This disclosure provides systems, methods and apparatus for wireless communications that support fallback from a 2-step to a 4-step random access procedures. A user equipment (UE) may establish a connection with a base station using a random access procedure. The random access procedure may be a 2-step random access procedure and reduce a number of handover exchange messages. The 2-step random access procedure may include the UE transmitting, to the base station, a first random access message including a preamble and a payload. In some implementations, the base station may receive the preamble but fail to receive or decode the payload. The random access procedure may utilize the received preamble information instead of performing retransmission of the first random access message. The base station may transmit a second random access message to the UE indicating, explicitly or implicitly, a fallback to a 4-step random access procedure for connection establishment.

Abstract: This disclosure provides systems, methods, and apparatus, including computer programs encoded on computer storage media, for enabling user equipment (UE) and a base station (BS) to communicate using a set of frequency resources in which a subset of frequency resources include a phase tracking reference signal (PTRS). In one aspect, the UE may measure the PTRS in the subset of frequency resources, and select a phase noise compensation that is used to demodulate a communication from the BS. The subset of frequency resources may be selected from the set frequency resources based on channel conditions of different subsets of frequency resources. The BS may provide an indication of the selected subset of frequency resources to the UE, such as in control information that schedules the communication from the BS.

Abstract: Aspects relate to techniques for exchanging resource pool (RP) configurations between wireless communication devices. A transmitting wireless communication device can transmit a remaining minimum system information (RMSI) message including a RP configuration of the transmitting wireless communication device to at least one receiving wireless communication device. The RMSI message is transmitted within a minimum resource block set that is common to both the transmitting wireless communication device and the at least one receiving wireless communication device. The transmitting wireless communication device may then communicate with the at least one receiving wireless communication device on a sidelink based on the RP configuration.

Abstract: Certain aspects of the present disclosure provide techniques for user equipment (UE) cooperation. Certain aspects provide a method for wireless communication by a target UE. The method generally includes receiving availability information indicating availability of one or more candidate UEs for cooperating with the target UE for communicating with a network entity, receiving assistance information from at least one of the candidate UEs, establishing a cooperation connection with the at least one of the candidate UEs based on the assistance information, and transmitting, to the network entity, an indication of UE capability based on the cooperation connection.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive configuration information associated with a first sounding reference signal (SRS) resource set and a second SRS resource set. The UE may receive downlink control information (DCI) that schedules a spatial division multiplexing (SDM) physical uplink shared channel (PUSCH) communication, the DCI including a plurality of fields associated with the SDM PUSCH communication. Numerous other aspects are provided.

Abstract: Methods, apparatuses, and computer-readable medium for sidelink communications may be provided. An example method may include receiving, from a second UE, a sidelink communication. The example method may include transmitting, to the second UE based on the sidelink communication, a physical sidelink feedback channel (PSFCH), the PSFCH spanning multiple symbols in a time domain, including a set of repetitions in a frequency domain, or spanning more than one resource blocks (RBs).

Abstract: Disclosed are techniques for wireless communication. In an aspect, a first user equipment (UE) obtains one or more first reception characteristics of a channel sounding signal transmitted by a second UE during a first transmission occasion of a detection duration, obtains one or more second reception characteristics of the channel sounding signal transmitted by the second UE during a second transmission occasion of the detection duration, and performs one or more sensing operations based on a difference between the one or more first reception characteristics and the one or more second reception characteristics indicating a presence, absence, or movement of an object.