Methods, systems, and devices for wireless communications are described. In some examples, a wireless communications system may support short reference signals for sidelink communication. A transmitting user equipment (UE) and a receiving UE may receive, from a base station, configuration signaling that indicates a set of sidelink resources that includes a set of slots within a subcarrier. A subset of the slots may include a first set of symbols allocated to a physical sidelink shared channel (PSSCH) and a second set of symbols allocated to a reference signal, where the first set of symbols comes before the second set of symbols in a time domain. The transmitting UE may transmit, to the receiving UE, a reference signal over the second set of symbols and the receiving UE may utilize the reference signal to decode data message received from the transmitting UE.

This disclosure provides systems, methods and apparatus, for measurement and reporting procedures associated with a sidelink positioning reference signal (SL-PRS). In one aspect, a first user equipment (UE), which may function as a sidelink anchor node, may transmit an SL-PRS to a second UE in accordance with a slot format or structure that is dedicated for SL-PRS transmissions. The first UE may select resources for the transmission of the SL-PRS via sensing and exclusion or using a set of resources that are dedicated for SL-PRS transmissions. The second UE may receive the SL-PRS and use the SL-PRS to acquire positioning information, in accordance with an observed time difference of arrival (OTDOA)-based positioning method, or may transmit a second SL-PRS to the first UE to facilitate acquisition of positioning information at the first UE, in accordance with a round-trip-time (RTT)-based positioning method.

The present invention provides a method performed by user equipment, and user equipment. The method includes: determining sidelink resource pool configuration information; and determining the number Q′.sub.SCI2 of coded modulation symbols of second stage SCI. The second stage SCI is second stage sidelink control information carried by a physical sidelink shared channel (PSSCH).

Embodiments of this application provide a device-to-device based resource determining method and device, which may be applied to a D2D system (for example, a system such as an internet of vehicles, V2X, or V2V). The method includes: receiving first information sent by a first terminal device, where the first information indicates a second terminal device to send assistance information; and sending the assistance information to the first terminal device, where the assistance information is used to assist the first terminal device in selecting a resource for data transmission. The second terminal device assists the first terminal device in determining the resource for data transmission, instead of completely determining, by a terminal device that sends data, the resource for data transmission.

A method of operating a first device 100 in a wireless communication system is proposed. The method may comprise: generating a MAC PDU related to a groupcast transmission; and selecting at least one SL resource for a transmission of the MAC PDU among a plurality of candidate resources in a resource pool, wherein a first SL resource included in the at least one SL resource is included in a first SL DRX active time, and the first SL resource being selected outside the first SL DRX active time is not allowed, based on the MAC PDU being related to groupcast transmission.

A method by which a first device performs sidelink communication is provided. The method comprises the steps of: receiving, from a base station, a sidelink grant associated with a first retransmission resource and an initial transmission resource of a transport block; transmitting, to a second device, a PSCCH and a PSSCH associated with the PSCCH, on the basis of the initial transmission resource; determining a PSFCH resource for receiving a PSFCH from the second device, on the basis of the index of a slot and the index of a subchannel associated with the PSSCH; receiving, from the second device, the PSFCH on a first PSSCH, on the basis of the PSFCH resource; comparing a time interval between the PSFCH resource and the first retransmission resource with a minimum processing time required between the reception of the PSFCH and retransmission of the transport block.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a relay user equipment (UE) may receive, from a base station, a downlink control information (DCI) message scheduling a first transmission between a source node and the relay UE and a second transmission between the relay UE and a destination node. The UE may transmit, to the base station, at least one of: feedback regarding at least one of the first transmission or the second transmission, or the second transmission. Numerous other aspects are described.

The present disclosure provides a method for sidelink communication. The method includes: a first terminal device acquires a first sidelink resource reserved for a second terminal device; and the first terminal device sends information of the first sidelink resource to the second terminal device to enable the second terminal device to acquire the first sidelink resource according to the information of the first sidelink resource. In the method of the embodiment of the present disclosure, the first terminal device can acquire the first sidelink resource reserved for the second terminal device according to resource occupation of a region where the first terminal device is located, and the second terminal device sends data according to the first sidelink resource reserved for it.

A terminal includes a control unit configured to determine, in a case where a first transmission of transmitting an HARQ (Hybrid Automatic Repeat Request) response received from another terminal to a base station overlaps in at least in a time domain with a second transmission to a base station, at least one of a priority and a priority order, of each transmission, and to determine control associated with the first transmission and the second transmission, based on the priorities, and a transmission unit configured to perform the control associated with the first transmission and the second transmission, based on the determination, and the control unit changes control associated with determination of priority order of transmissions, based on a configuration associated with communication.

Embodiments of this application provide a resource indication information transmission method, a device, and a system, which are applicable to fields such as internet of vehicles, intelligent connected vehicle, assisted driving, and intelligent driving. In an example method, a first terminal device determines X sets of candidate single-time-unit resources based on a number of sub-channels to be used by a second terminal device for physical sidelink shared channel (PSSCH) and/or physical sidelink control channel (PSCCH) transmission, and indicates, to the second terminal device, K candidate single-time-unit resources whose time domain locations are in a first time window in the X sets of candidate single-time-unit resources. The second terminal device determines a first time-frequency resource based on the K candidate single-time-unit resources. The first time window is a time window included in a selection window corresponding to at least one of the X sets of candidate single-time-unit resources.