Abstract: A data transmission method and apparatus are applicable to fields such as V2X, intelligent driving, and connected vehicles. A probability of a collision between a high-priority PSSCH and a low-priority PSSCH is reduced, thereby improving QoS of the high-priority PSSCH. The method includes: obtaining resource pool configuration information including first resource pool information and second resource pool information, where the first resource pool information indicates a first resource pool, and the second resource pool information indicates a second resource pool; obtaining a first priority value corresponding to a physical sidelink shared channel PSSCH; when the first priority value is less than a first priority threshold, determining, in a partial-sensing-selection-based resource determination mechanism and/or a random-selection-based resource determination mechanism in the first resource pool, a resource for sending the PSSCH.

Abstract: This application relates to a communication method, an apparatus, and a system, and is applicable to fields such as Internet of Vehicles, intelligent driving, assisted driving, and intelligent connected vehicles. The method includes: determining a first time based on a first reference time and a first time offset, and sending, to a first terminal apparatus at the first time or before the first time, coordination information indicating a first resource, where the first resource is for determining a second resource for receiving sidelink information from the first terminal apparatus. Therefore, the time for sending the coordination information is limited. This ensures that the first terminal apparatus has sufficient time to determine, when the first terminal apparatus receives the coordination information, the second resource for sending the sidelink information, thereby improving reliability of sidelink communication.

Abstract: A beam training method and a related device are disclosed. The method includes: sending, by a first communications device, sidelink control information (SCI) to a second communications device, where the SCI is used to instruct the first communications device to send at least one channel state information-reference signal (CSI-RS) to the second communications device; and sending, by the first communications device, the at least one CSI-RS to the second communications device based on the SCI, where the at least one CSI-RS is used by the second communications device to determine that a beam corresponding to a CSI-RS with highest signal strength in the at least one CSI-RS is a beam for communication between the second communications device and the first communications device. The CSI-RS used for beam training is dynamically sent based on the instruction of the SCI.

Abstract: A method for determining a transport block size includes: determining an overhead of a sidelink data channel PSSCH demodulation reference signal (DMRS) in a physical resource block (PRB) of a first time-frequency resource, where the first time-frequency resource includes a first time unit in time domain; and determining, based on the overhead of the PSSCH DMRS, a number of resource elements (REs) on the first time-frequency resource that are for data transmission, where the number of REs for data transmission is for determining a transport block size (TBS) of the sidelink data channel PSSCH. The method provides a combined gain of a plurality of transmissions of a same transport block, and supports DMRS configurations of different quantities of DMRS symbols in initial transmission and retransmission of one transport block.

Abstract: A communication method and apparatus that is used in fields such as V2X, an internet of vehicles, intelligent driving, and assisted driving. The method includes a first terminal apparatus detects SCI from at least one second terminal apparatus, to determine a first resource. The first terminal apparatus sends, to the third terminal apparatus, first information for triggering determining of second information, and receives the second information from the third terminal apparatus. The first terminal apparatus determines, based on the first resource and the second resource, the resource for sending the data. The first terminal apparatus selects, based on a sensing result of the first terminal apparatus and the resource recommended by the third terminal apparatus, the resource for sending the data, so that both interference around the first terminal apparatus and interference around the third terminal apparatus are considered, thereby reducing interference and improving communication quality.

Abstract: This application relates to a communication method, apparatus, and system, and is applicable to fields such as internet of vehicles, intelligent driving, assisted driving, and intelligent connected vehicles. A first terminal apparatus detects sidelink control information from at least one second terminal apparatus to determine a first time-frequency resource. The first terminal apparatus sends first information to a third terminal apparatus, to trigger determining of second information. The first terminal apparatus receives the second information from the third terminal apparatus, to indicate a second time-frequency resource. The first terminal apparatus determines the third time-frequency resource based on the second time-frequency resource and the first time-frequency resource.

Abstract: A sidelink resource determining method includes determining, by a first terminal device, a first sidelink candidate resource through monitoring. The method also includes receiving, by the first terminal device, at least one piece of resource indication information from a second terminal device. The at least one piece of resource indication information indicates at least one second sidelink candidate resource obtained by the second terminal device through monitoring. The method further includes determining, by the first terminal device, a sidelink sending resource based on the first sidelink candidate resource and based on the at least one second sidelink candidate resource. The method additionally includes sending, by the first terminal device, sidelink control information and data on the sidelink sending resource.

Abstract: Example communication methods and apparatus are described. One example communication method includes receiving first indication information by a first communications device from a network device, where the first indication information indicates a first resource for sidelink communication. The first communications device sends the first data to a second communications device. The first communications device receives second indication information from the network device, where the second indication information is used to determine a second resource for transmitting feedback information. The first communications device receives feedback information of the first data from the second communications device.

Abstract: This application provides a method for determining a transport block size and a communication apparatus, which may be used in systems such as vehicle-to-everything, V2X, and V2V. A receive-end terminal device and a transmit-end terminal device may determine a quantity of encoded symbols based on a symbol length used for sidelink communication in a time unit and an scaling factor, and may further determine a transport block size of a data channel based on the quantity of encoded symbols. Therefore, for all slots used for sidelink communication, a same quantity of encoded symbols can be determined, and a same transport block size can be further determined.

Abstract: A communication method and a communication apparatus, the method including determining, based on a quantity of resource elements (REs) that are in a first time-frequency resource and that are used to transmit first information, a quantity of REs that are in the first time-frequency resource and that are used to transmit data, the first time-frequency resource including a first time unit in time domain and including a data channel resource in frequency domain, where the first information includes at least one of a control channel, a control channel demodulation pilot, a data channel demodulation pilot, second-stage control information, a phase tracking reference signal (PTRS), or a channel state information reference signal (CSI-RS).

Abstract: A first communications device obtains a first resource and a second resource; the first communications device sends first control information and first data to at least one communications device in a group on the first resource, where the first communications device and the at least one communications device in the group belong to a first communications device group, and the first communications device and the at least one communications device in the group each have a group identifier of the first communications device group; and the first communications device receives acknowledgement information from a second communications device on the second resource, where the second communications device is the at least one communications device in the group.

Abstract: This application provides example reference signal transmission methods, apparatuses, and systems. An example method includes determining a first transmission parameter in at least two transmission parameters, where any two of the at least two transmission parameters are different, and the first transmission parameter is used to determine a first transmission resource for a first reference signal. The first reference signal is sent to a second communication apparatus on the first transmission resource.

Abstract: Example response information sending and receiving methods and apparatus are described. One example sending method includes receiving first indication information by a first communications device from a network device, where the first indication information is used to indicate a first resource for transmitting first data. The first communications device sends the first data to a second communications device on the first resource. The first communications device receives second indication information from the network device, where the second indication information is used to indicate a second resource for transmitting response information of the first data. The second source and the first resource do not include a same resource. The first communications device receives the response information of the first data from the second communications device on the second resource.

Abstract: A beam training method and a related device are disclosed. The method includes: sending, by a first communications device, sidelink control information (SCI) to a second communications device, where the SCI is used to instruct the first communications device to send at least one channel state information-reference signal (CSI-RS) to the second communications device; and sending, by the first communications device, the at least one CSI-RS to the second communications device based on the SCI, where the at least one CSI-RS is used by the second communications device to determine that a beam corresponding to a CSI-RS with highest signal strength in the at least one CSI-RS is a beam for communication between the second communications device and the first communications device. The CSI-RS used for beam training is dynamically sent based on the instruction of the SCI, and therefore, flexibility and efficiency of beam training are improved.

Abstract: A method comprises: selecting, from a first resource set or a second resource set, a resource occupied by second-level control information, wherein the first resource set occupies an nth symbol to an (n+k)th symbol in a time unit, a time domain start symbol of the second resource set is an (n+k+1)th symbol in the time unit, n is 0 or 1, k is a positive integer, the first resource set comprises a resource used to send first-level control information, and the first-level control information occupies all symbols occupied by the first resource set; and sending the first-level control information and the second-level control information.

Abstract: A beam training method and a related device are disclosed. The method includes: sending, by a first communications device, sidelink control information (SCI) to a second communications device, where the SCI is used to instruct the first communications device to send at least one channel state information-reference signal (CSI-RS) to the second communications device; and sending, by the first communications device, the at least one CSI-RS to the second communications device based on the SCI, where the at least one CSI-RS is used by the second communications device to determine that a beam corresponding to a CSI-RS with highest signal strength in the at least one CSI-RS is a beam for communication between the second communications device and the first communications device. The CSI-RS used for beam training is dynamically sent based on the instruction of the SCI.

Abstract: A sidelink control information sending and receiving method, a terminal apparatus, and a system are provided in this application, and may be applied to fields such as vehicle-to-everything (for example, V2X, LTE-V, or V2V), intelligent driving, and an intelligent connected vehicle. In a scenario in which second-stage SCI is not required in a sidelink communication system, a transmit end apparatus in sidelink communication indicates, by using first-stage SCI, a cyclic redundancy check bit corresponding to the first-stage SCI, or a reference signal used to demodulate the first-stage SCI, that the transmit end apparatus is not to send the second-stage SCI to a receive end apparatus. In this way, the transmit end apparatus may flexibly choose, based on a specific scenario of the sidelink communication, to use 2-stage SCI or 1-stage SCI, to avoid resource waste caused by using the 2-stage SCI in any scenario of the sidelink communication, thereby improving resource utilization efficiency.

Abstract: A data transmission method, a communications device, a network device, and a system are provided, applicable to Internet of Vehicles, self-driving, or, for example, V2X, V2V, LTE-V, and eV2X. The sending method includes: sending, by a first communications device, first indication information to a second communications device on a first resource, where the first indication information is used to indicate a location relationship between a resource on which the first communications device sends control information and a resource on which the first communications device sends data, and the location relationship is a frequency division multiplexing relationship or a time division multiplexing relationship; sending, by the first communications device, the control information to the second communications device on the first resource; and sending, by the first communications device based on the control information, the data to the second communications device on the first resource.

Abstract: A communication method and apparatus are provided, and are applicable to fields such as V2X, internet of vehicles, intelligent connected vehicles, assisted driving, and intelligent driving. The method includes: A first terminal device may map first control information to a first transmission resource, and map second information including second control information and data to a second transmission resource and a third transmission resource, and may map the second information to the second transmission resource that does not overlap the first transmission resource in time domain.

Abstract: This application provides example signal transmission method and apparatus. One example method includes sending, by a first terminal device to a second terminal device, indication information indicating a signal transmission resource. Listen before talk (LBT) is performed by the first terminal device before transmission with the second terminal device is performed. Transmission with the second terminal device is performed by the first terminal device according to the indication information.