Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may identify one or more spectral efficiency ranges that are to be used to select a modulation and coding scheme (MCS) for a sidelink communication. The UE may transmit the sidelink communication using the MCS selected based at least in part on the one or more spectral efficiency ranges. Numerous other aspects are provided.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, on a sidelink, a groupcast communication and a unicast communication concurrently from a transmitter. The UE may determine a feedback sequence to be transmitted to indicate joint acknowledgment or negative acknowledgement feedback for the groupcast communication and the unicast communication based at least in part on a decoding of the groupcast communication. The UE may transmit the feedback sequence in one or more sidelink feedback resources associated with a sidelink subchannel via which at least one of the groupcast communication or the unicast communication is received. Numerous other aspects are provided.

Abstract: Aspects described herein relate to determining, by a node, to establish a first connection with a first upstream node for receiving downlink communications, and determining, by the node, to establish a second connection with a second upstream node for transmitting uplink communications or establishing a second connection with the same upstream node based on a second transmit/receive beam pair. The first connection can be established with the first upstream node based on a first transmit/receive beam pair. The second connection can be established with the second upstream node (or the same upstream node) based on a second transmit/receive beam pair and concurrently with the first connection is established with the first upstream node.

Abstract: Certain aspects of the present disclosure provide techniques for conveying information via medium access control (MAC) control element (CEs). In some cases, the MAC-CEs may relate to sidelink communications between two user equipments (UEs). A first wireless node may send the first MAC-CE on at least one of a sidelink or a cellular link and provide providing routing information for the first MAC-CE. The routing information may indicate, for example, a source node, a destination node, or a transit route through one or more nodes. The routing information may also indicate whether traffic sent with the first MAC-CE is relayed traffic or traffic originating at the first node.

Abstract: A method, a computer-readable medium, and an apparatus for wireless communication at a first user equipment (UE). A channel state information (CSI) report trigger can be received from a second UE, and a channel state information reference signal (CSI-RS) can be received from the second UE in a same slot as the CSI report trigger. A CSI report can be transmitted to the second UE based on the CSI-RS, the CSI report including information identifying the CSI-RS on which the CSI report is based. The UE that triggered the CSI report can determine the CSI-RS on which the CSI report is based using the information included in the CSI report.

Abstract: The described techniques may allow transmitting devices to adjust transmission parameters (e.g., transmit power, modulation and coding scheme (MCS)), until reaching an optimal power and/or MCS. These techniques may allow devices to use power efficiently and reduce inter-device interference in a vehicle-to-everything sidelink system. For example, a transmitting device may begin transmissions to a receiving device with initial transmission parameters, which may be configured using a transmission priority and a channel busy ratio. The transmitting device may lower power and/or increase MCS in each of its subsequent transmissions of the same priority, until the receiving device transmits a feedback message that indicates a low signal quality or a failure to decode a previous transmission. The transmitting device may then increase its transmit power and/or decrease its MCS to an acceptable level for a specified time duration based on receiving the feedback message.

Abstract: Aspects of the present disclosure provide a method for wireless communications by a peer device. The method generates control information to schedule peer-to-peer communication. The control information includes a first portion with a first set of data and a second portion with a second set of data. The method then transmits the first portion of the control information in a first stage using first time and frequency resources. The first portion indicates a control information format of the second portion. The method further transmits the second portion of the control information in a second stage using second time and frequency resources and the indicated control information format.

Abstract: Aspects of the disclosure relate to methods and apparatus for scheduling traffic between a transmitting device and a receiving device. A transmitting device negotiates with a receiving device to reserve a plurality of slots for communicating data with the receiving device. The transmitting device then sends, at a beginning of one slot of the reserved plurality of slots, a request-to-send (RTS) message indicating a number of slots of the reserved plurality of slots the transmitting device intends to use for transmitting the data. The transmitting device receives, from the receiving device, a clear-to-send (CTS) message in each slot of the number of slots based on the RTS message and transmits the data to the receiving device in each slot of the number of slots upon receiving the CTS message in each slot. Other aspects, embodiments, and features are also claimed and described.

Abstract: The present disclosure relates to dynamic antenna array reconfiguration and signaling in millimeter wave bands. A user equipment (UE) may detect an antenna array change condition. The UE may transmit a request for beam training for an antenna array configuration in response to the detecting. The request for beam training may include a requested antenna array configuration for the UE and an indication of beam weights to use with the requested antenna array configuration. A base station may determine whether to grant or deny the requested antenna array configuration for the UE. The UE may receive, from the base station, an indication of an antenna array configuration for the UE. The base station may transmit the number of reference signals as a set of contiguous channel state information reference signals (CSI-RS). The UE may train the reconfigured active antenna array configuration based on the reference signals.

Abstract: Aspects described herein relate to measuring a signal quality at at least one receive beam while transmitting, in full duplex communications, over each of one or more transmit beams associated with the at least one receive beam, and determining, based at least in part on the measured signal quality associated with each of the one or more transmit beams and the at least one receive beam, a transmit/receive beam pair to use in full duplex communications with one or more other nodes.

Abstract: Methods and apparatus related to wireless communication, for example, to 5G New Radio (NR) device-to-device (D2D) (e.g., vehicle-to-vehicle (V2V) or vehicle-to-everything (V2X)) ultra-reliable and low-latency communications (URLLC) communication are provided. In aspects, a method of wireless communication by a user equipment (UE) may include transmitting data associated with a URLLC communication in a first set of one or more portions of a wireless communication structure having a plurality of portions, and re-transmitting the data associated with the URLLC communication in a second set of one or more portions of the wireless communication structure, wherein one or more slot structures of the wireless communication structure are defined by the plurality of portions, the first set is based on a first mini-slot structure, the second set is based on a second mini-slot structure, and a mini-slot structure is smaller than a slot structure Numerous other aspects are provided.

Abstract: Disclosed are techniques for using ranging signals to determine a position of a pedestrian user equipment (P-UE). In an aspect, a UE receives a plurality of ranging signals transmitted by one or more UEs, measures one or more properties of each of the plurality of ranging signals, and calculates an estimate of the position of the P-UE based on the one or more properties of each of the plurality of ranging signals. In an aspect, the P-UE transmits a plurality of ranging signals, receives a first message and a second message from first and second vehicle UEs (V-UEs), the first and second messages including first and second estimated positions of the P-UE and associated first and second confidences, and calculates an estimate of the position of the P-UE based on the first estimated position, the first confidence, the second estimated position, the second confidence, or a combination thereof.

Abstract: Methods, apparatuses, and computer-readable mediums for wireless communication are disclosed by the present disclosure. In an example, a client wireless device may transmit a random access channel (RACH) preamble on a first time domain resource to a recipient such as a host wireless device. The client wireless device may later transmit a second RACH message to the recipient on a second time domain resource after the first time domain resource. The second time domain resource may be defined by a mapping from the first time domain resource. The recipient may transmit a third RACH message establishing a communication session between the host wireless device and the client wireless device. The second RACH message may include one or more of: an identifier of the wireless device; an identifier of the recipient of the second RACH message; a resource configuration for subsequent RACH messages; or timing information.

Abstract: Methods, systems, and devices for sidelink groupcast communications are described. A user equipment (UE) may transmit a beam training request to a base station to determine beams for use with other UEs in a sidelink groupcast communications group. The base station may receive the beam training request, identify wireless resources that a group of UEs may use to perform beam training, and may transmit a beam training grant to each UE of the group of UEs. The UE may transmit a number of training beams using the wireless resources provided in the beam training grant, and the other UEs may measure received signals on the wireless resources to identify one or more beams. Each UE may provide a beam training report to the base station. The base station, based on the beam training reports, may determine beams and resources for use in the groupcast sidelink communications.

Abstract: Methods, systems, and devices for wireless communications are described. A first user equipment (UE) may transmit, to a base station, a sidelink scheduling request for groupcast sidelink communications with a set of one or more UEs. The base station may determine one or more UEs of the set of UEs and time-frequency resources for groupcast sidelink communication between the first UE and the one or more UEs. The first UE may receive, from the base station, a groupcast sidelink grant that indicates time-frequency resources for groupcast sidelink communications between the first UE and one or more UEs. The first UE may transmit, via the time-frequency resources indicated by the groupcast sidelink grant, a groupcast sidelink message to the one or more UEs. The one or more UEs may also receive the sidelink grant, and may monitor the time-frequency resources for a groupcast sidelink communication from the first UE.

Abstract: Methods, systems, and devices for wireless communications are described in which a user equipment (UE) of a group of UEs may communicate with other members of the group to provide data or other information via sidelinks. The UE may transmit a groupcast sidelink request to the base station. After receiving the sidelink request, the base station may send a sidelink grant (e.g., transmit or receive grant) in downlink control information (DCI) to the UEs in the sidelink groupcast communications group. The sidelink grant may include information for each hop such as which UEs are going to transmit or receive, the reception or transmission beams of the UEs, time and frequency resources, or the data to forward or relay. In some examples, a UE may relay information to other UEs in the sidelink groupcast communications group.

Abstract: Disclosed are techniques for non-line-of-sight (NLOS) target detection. In an aspect, a source vehicle receives, from a roadside unit (RSU), a notification that the RSU is capable of repeating radar signals transmitted by the source vehicle in NLOS directions from the source vehicle, receives, from an active radar repeater associated with the RSU, radar signals for a radar beam sweep in at least one NLOS direction from the source vehicle, receives an angle of each beam of the radar beam sweep, and performs target object detection based on the radar signals for the at least one NLOS direction and the angle of each beam of the radar beam sweep. Example architectures for the active radar repeater are also disclosed.

Abstract: Methods, systems, and devices are described for signaling protocols for proximity service functions in a wireless communication system. A first wireless device may identify a wireless relay requirement associated with the first wireless device. A proximity service protocol may be initiated between the first wireless device and a second wireless device based at least in part on the identified wireless relay requirement. The proximity service protocol may be initiated prior to an initiation of a communication data exchange between the first wireless device and the second wireless device. A relay link may be established, via the ProSe protocol, between the first wireless device and the second wireless device based at least in part on the identified wireless relay requirement.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment may identify two or more peer-to-peer (P2P) communications to be combined based at least in part on a respective location of each of two or more originating UEs from which the two or more P2P communications are received; combine the two or more P2P communications, using network coding, to form a combined P2P communication; and transmit the combined P2P communication. Numerous other aspects are provided.

Abstract: Improvements may be made for an apparatus performing congestion control considering different technologies, types of radio resources, and priorities of different packets. The apparatus may be a UE. The UE determines a channel busy ratio (CBR). The UE determines one or more channel resource utilization limits based on the CBR, where each channel resource utilization limit of the one or more channel resource utilization limits corresponds to a respective packet priority. The one or more channel resource utilization limits are also a function of a CBR limit. The UE controls transmission of a plurality of packets based on the one or more channel resource utilization limits, and each packet of the plurality of packets has a respective packet priority.