Abstract: Disclosed are techniques for wireless communication. In an aspect, a transmitter user equipment (UE) determines a first demodulation reference signal (DMRS) pattern for a first slot allocated for transmission over a sidelink between the transmitter UE and a receiver UE, wherein the first DMRS pattern is determined based at least on the first slot having a first slot format of two or more slot formats, and transmits, to the receiver UE, DMRS in the first slot according to the first DMRS pattern. In an aspect, the receiver UE determines the first DMRS pattern for the first slot based at least on the first slot having the first slot format, and receives, from the transmitter UE, DMRS in the first slot according to the first DMRS pattern.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a sidelink transmitting (Tx) mobile station may perform a sub-band channel access in candidate frequency resources of an unlicensed band for a sidelink positioning reference signal (PRS) transmission to occur in time resources. The Tx may transmit, from the sidelink Tx mobile station to a sidelink receiving (Rx) mobile station, the sidelink PRS transmission in one or more sub-bands of the unlicensed band that have passed the sub-band channel access. Numerous other aspects are described.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment may generate a pseudorandom noise (PN) sequence, modulate the PN sequence based at least in part on a modulation order parameter, and transmit the PN sequence in one or more symbols prior to transmitting sidelink data. The one or more symbols used to transmit the PN sequence may be used for automatic gain control (AGC) training at a receiving device. The user equipment may then transmit the sidelink data in a plurality of symbols that are subsequent in time relative to the one or more symbols used to transmit the PN sequence, and the receiving device may process the sidelink data based on the AGC training. Numerous other aspects are provided.

Abstract: Aspects of the present disclosure provide apparatus, methods, processing systems, and computer readable mediums for channel and/or resource selection for sidelink communications. In some cases, a transmitter user equipment UE may transmit, on a sidelink channel used for communicating with other UEs, a control message indicating at least one range, monitor for feedback associated with detection of the control message by one or more other UEs within the indicated range, and transmit data if the feedback indicates at least that the sidelink channel is free.

Abstract: Wireless communications systems and methods related to channel occupancy time (COT) sharing for sidelink communications are provided. A first user equipment (UE) receives, from a second UE, a first sidelink transmission during a first channel occupancy time (COT), where the first COT is associated with the second UE. The first UE determines whether the second UE is one of two or more UEs intended to receive a second sidelink transmission. The first UE transmits, to the two or more UEs, the second sidelink transmission during a portion of the first COT based on COT sharing. The COT sharing is in response to determining the second UE is one of the two or more UEs intended to receive the second sidelink transmission.

Abstract: Apparatus, methods, and computer-readable media for facilitating a cloud-based vehicle XR user experience are disclosed herein. An example method for wireless communication at a user equipment (UE) includes transmitting a request for a vehicle extended reality (XR) session. The vehicle XR session may be based on a first user XR stream including a vehicle XR component associated with a vehicle and a first user XR component associated with a first user. The first user may have an association with the vehicle. The example method also includes transmitting uplink information associated with the first user XR stream. The example method also includes receiving rendering information associated with the first user XR stream. The rendering information may be based on the uplink information.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may identify one or more channel occupancy times (COTs) associated with a first radio access technology (RAT) on an unlicensed band. The UE may calculate a congestion control parameter associated with a second RAT on the unlicensed band, wherein the congestion control parameter is calculated by excluding sub-channels in the one or more COTs. The UE may use the congestion control parameter to communicate via the unlicensed band. Numerous other aspects are provided.

Abstract: Methods, systems, and devices for wireless communication are described. A communication device, such as a user equipment (UE) may determine a transmit diversity configuration indicating a transmit diversity criterion for declaring a result of a channel access procedure for a plurality of component carriers in a shared radio frequency spectrum band. The UE may perform the channel access procedure for the plurality of component carriers in the shared radio frequency spectrum band to determine the result of the channel access procedure based at least in part on the transmit diversity criterion. As a result, the UE may transmit or refrain from transmitting a message over at least one component carrier of the plurality of component carriers based at least in part on the result of the channel access procedure.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) may identify a transmit diversity configuration for transmitting multiple sidelink messages. The UE may identify a transmit diversity configuration that indicates a set of component carriers (CCs) available for sidelink communication. The UE may transmit, based on the transmit diversity configuration, a first sidelink message having a first redundancy version (RV) of a transport block (TB), and a second sidelink message having a second RV of the TB, on multiple CCs. In a second case, the UE may identify a transmit diversity configuration indicating a set of precoding matrices. The UE may transmit the first sidelink message, including a TB or an RV of a TB, precoded using a first precoding matrix and a second sidelink message, including a TB or an RV of a TB, precoded using a second precoding matrix on multiple CCs.

Abstract: In an aspect, the present disclosure includes a method and apparatus for sidelink communications for identifying a number of non-sidelink occupied resources in a measurement window having a total number of resources in an unlicensed spectrum, wherein the total number of resources can be used by sidelink transmissions and non-sidelink transmissions, determining a channel occupancy ratio (CR) limit for a sidelink transmission based on at least a channel busy ratio (CBR) determined accounting for at least the number of non-sidelink occupied resources in the measurement window, calculating a CR for a sidelink transmission, and transmitting, or refraining from transmitting, the sidelink transmission respectively based on whether the CR does not or does exceed the CR limit.

Abstract: In an aspect, the present disclosure includes a method and apparatus for sidelink communications for identifying at least one slot in a measurement window as a channel busy ratio (CBR) relevant slot, calculating a CBR based on at least a measurement in at least the CBR relevant slot, and transmitting, or refraining from transmitting, a sidelink transmission based at least on the CBR.

Abstract: Wireless communications systems and methods related to channel occupancy time (COT) sharing for sidelink communications in unlicensed bands are provided. A method for wireless communication by a first user equipment (UE) may include measuring a first reference signal received power (RSRP) of a physical sidelink feedback channel (PSFCH) transmission transmitted during a channel occupancy time (COT) initiated by a second UE and accessing a first slot of the COT based on the first RSRP.

Abstract: Methods, systems, and devices for wireless communications are described. One or more user equipments (UEs) may communicate in a wireless communications system by transmitting and receiving sidelink messages from other UEs. The UEs may transmit acknowledgement (ACK) or negative acknowledgment (NACK) feedback based on reception of sidelink messages for other UEs. The UEs may identify a sidelink feedback resource set including a set of feedback transmission slots for transmitting sidelink feedback. The UEs may perform NACK-only feedback, and may streamline feedback transmissions based on monitoring for other NACKs from other UEs. The UEs may prioritize feedback transmissions when the UE has multiple feedback transmissions queued, and when a UE has feedback to transmit and to receive in overlapping transmission time intervals (TTIs).

Abstract: Methods, systems, and devices for wireless communication are described to support configuring a user equipment (UE) operating in unlicensed spectrum with a set of component carriers (CCs) for sidelink communications using the unlicensed spectrum. In a first example, a UE may select a CC from the set of candidate CCs, for example, using a carrier selection configuration, and may select a resource in the CC for a sidelink communication. In a second example, a UE may select multiple candidate resources for a sidelink communication, for example, using a resource selection configuration and based on sensing performed by the UE. To indicate the reservation of a candidate resource, the UE may indicate both a CC in which the reserved resource is located and a location of the reserved resource within the carrier. The UE may transmit a sidelink message using a selected candidate resource in the unlicensed spectrum.

Abstract: Aspects for reducing interference for transmissions in unlicensed frequency bands are disclosed. An apparatus, e.g., a user equipment (UE) with information to transmit, identifies before transmitting the information in an unlicensed frequency spectrum, a specified duration of a listen-before-talk (LBT) operation in that spectrum. Based on the specified duration, the UE reduces a transmission time duration of a slot of the UE to increase a time duration of a remainder of the slot sufficient to prevent, or decrease the likelihood of, a transmission by the UE in the slot from interfering with an LBT operation by another UE.

Abstract: Methods, systems, and devices for wireless communication are described to support selection of an unoccupied sidelink resource associated with a higher communication quality in a shared spectrum. User equipments (UEs) operating in shared spectrum may be configured with a set of candidate carriers for sidelink communications using the shared spectrum. A transmitting UE may select a number of resources for a sidelink transmission that are available in a same transmission time occasion and on multiple carriers of the set of carriers. The UE may perform a channel access procedure for each carrier of the multiple carriers prior to the transmission time occasion and may transmit a sidelink communication on at least one selected resource if the channel access procedure succeeds in at least one of the carriers of the multiple carriers.

Abstract: Techniques for cross channel occupancy time (COT) hybrid automatic repeat request (HARQ) feedback transmission for sidelink communication in unlicensed spectrum may be performed. In an example, a receiving user equipment (UE) may receive, from a transmitting UE, a first transmission in a first channel occupancy time (COT). The receiving UE may also determine a first feedback occasion is after a last slot of the first COT. The receiving UE may also determine one or more feedback configurations. The receiving UE may also transmit, to the transmitting UE, a feedback message indicating decoding of the first transmission in the first feedback occasion or a second feedback occasion based on the one or more feedback configurations.

Abstract: A first UE may configure, during a COT, an initial transmission and one or more subsequent transmissions that follow the initial transmission. The one or more subsequent transmissions are configured to prevent a release of the COT. Based on the configuration, the first UE may transmit the initial transmission including an indication of the COT and a time period for transmitting the one or more subsequent transmissions. The first UE may subsequently transmit the one or more subsequent transmissions during the indicated time period. A second UE may receive the indication of the COT and the time period where the release of the COT is prevented. The second UE may prepare a packet for transmission during the time period where the release of the COT is prevented and transmit the packet during the COT following the time period where the release of the COT is prevented.

Abstract: Method and apparatus for a prioritization of synchronization signals for NR-LTE in-band coexistence. The apparatus detects a first sidelink synchronization signal from a first RAT and a second sidelink synchronization signal from a second RAT. The apparatus determines a priority between a synchronization source associated with the first RAT and the second RAT. The apparatus transmits data using a timing based on a determination of the priority between the first RAT and the second RAT. The apparatus determines to transmit a sidelink synchronization signal to be the synchronization source in response to detecting the first sidelink synchronization signal from the first RAT. The apparatus determines to transmit at least one of the first sidelink synchronization signal or the second sidelink synchronization signal.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) may receive an indication of a time offset for synchronization signal resources for synchronization signals associated with a first radio access technology (RAT). The UE may determine the synchronization signal resources and a synchronization periodicity based on the indication and a penetration ratio of UEs associated with the first RAT. The UE may selectively transmit the synchronization signals on the synchronization signal resources and according to the synchronization periodicity. Additionally, or alternatively, the UE may determine that other synchronization signal resources are allocated for a second RAT and may select resources for communications associated with the first RAT based on determining that the other synchronization signal resources are allocated. The UE may perform communications associated with the first RAT based on selecting the resources.