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 a 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. In this way, initial transmission or retransmission of a transport block can be performed in each slot used for sidelink communication, to avoid a limitation on selection of a transmission resource and a resulting transmission delay.

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: This application provides a power control method and a power control apparatus. The method includes: sending, by a first terminal device, a first signal to a second terminal device at a first transmit power; receiving, by the first terminal device, first information from the second terminal device, where the first information is used to indicate or includes a first received power, and the first received power is a received power of the first signal; determining, by the first terminal device, an estimated value of a path loss between the first terminal device and the second terminal device based on the first transmit power and the first received power. According to this application, power control can be properly performed. This application may be applied to an internet of vehicles, for example, V2X, LTE-V, and V2V, or may be applied to fields such as D2D, intelligent driving, and intelligent connected vehicles.

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: 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 first terminal device determines a transmit power of a data channel, wherein the transmit power of the data channel comprise a first data channel part and a transmit power of a second data channel part, where the first data channel part is a part of the data channel that has a same time domain resource with a control channel, and the second data channel part is another part of the data channel that has a different time domain resource with the control channel. The first terminal device sends data in the first data channel part at the transmit power of the first data channel part, and sends data in the second data channel part at the transmit power of the second data channel part. This application may be applied to internet of vehicles, for example, V2X, LTE-V, and V2V.

Abstract: This application provide a method, includes: receiving first information, where the first information is included in sidelink control information (SCI); obtaining a cyclic redundancy check, CRC, code based on the first information; and obtaining the reference signal sequence of the channel state information reference signal, CSI-RS, based on a scrambling identity, where the scrambling identity is L least significant bits of the CRC code or L most significant bits of the CRC code and L is a positive integer.

Abstract: A method includes: receiving sidelink data from a second apparatus from a plurality of frequency domain resource sets on a plurality of carriers in a first slot, where each of the plurality of carriers includes at least one frequency domain resource set; determining a feedback resource from a plurality of candidate feedback resources corresponding to the plurality of frequency domain resource sets, where a candidate feedback resource is configured in each of the plurality of frequency domain resource sets, the feedback resource belongs to one of the plurality of frequency domain resource sets in frequency domain, and the feedback resource is located in a second slot in time domai; and sending feedback information of the sidelink data to the second apparatus on the feedback resource.

Abstract: The method includes: determining v adjustment factors corresponding to v layers in multiple-input multiple-output, where one layer corresponds to one adjustment factor, and v is an integer greater than 1; and performing an encoding procedure on a first transport block based on the v adjustment factors, where the encoding procedure includes: determining a quantity of bits of the first transport block, performing rate matching, and performing layer mapping.

Abstract: A method includes: determining a start time point of a resource selection window based on a first time point for triggering resource selection, and selecting a transmission resource in the resource selection window. A time interval between the start time point of the resource selection window and the first time point is not less than duration required by a terminal device to perform first-type listen-before-talk (LBT).

Abstract: This application provides a communication method and apparatus used for the internet of vehicles, for example, vehicle to everything (V2X), Long Term Evolution-Vehicle (LTE-V), and vehicle-to-vehicle communication (V2V). The method includes: a first terminal apparatus generates, based on indication information such as an aggregation level of a control channel or a demodulation reference sequence configuration of a data channel, a demodulation reference sequence of another control channel, and sends the demodulation reference sequence to a second terminal apparatus. The second terminal apparatus can obtain the indication information in a process of detecting the demodulation reference sequence of the other control channel, to demodulate the control channel or the data channel.

Abstract: This application provides a sidelink feedback information transmission method and a communication apparatus. The method includes: A first terminal sends first indication information to a second terminal, where the first indication information indicates that first channel occupancy time includes a first physical sidelink feedback channel PSFCH resource; and the first terminal receives, on the first PSFCH resource, feedback information from the second terminal. In this application, the second terminal sends the feedback information by using a resource contended by the first terminal. Compared with a solution in which the second terminal contends for a resource to send the feedback information, this solution in this application can reduce a possibility of a contention failure of the second terminal, and improve accuracy of data transmission.

Abstract: In accordance with an embodiment, a method includes: accessing, by a first terminal device based on a listen before talk (LBT) process, a channel and determining a channel occupancy time; determining, by the first terminal device, a sidelink resource in the channel occupancy time; and sending, by the first terminal device on the sidelink resource, sidelink information to a second terminal device, or receiving, on the sidelink resource, sidelink information from the second terminal device.

Abstract: A communication method and apparatus are disclosed. A first terminal apparatus may receive first data from a second terminal apparatus, and determine a feedback time unit in a channel occupancy time, where the feedback time unit corresponds to the first data. The first terminal apparatus may transmit first feedback information on a first frequency domain resource in the feedback time unit, and transmit second feedback information on a second frequency domain resource. The first feedback information is an acknowledgment or a negative acknowledgment for the first data, the first frequency domain resource is determined based on a time-frequency resource carrying the first data, the first frequency domain resource and the second frequency domain resource belong to a first channel, and the first frequency domain resource and the second frequency domain resource do not overlap.

Abstract: A communication method and related terminal apparatus are provided, which are applicable to the fields such as V2X, intelligent driving, assisted driving, connected vehicles, internet of vehicles, and the like. A first terminal apparatus determines, based on identifier information and resource configuration information, a resource for sending an energy-saving signal, so that a destination of the energy-saving signal, namely, a second terminal apparatus, may learn of a source of the energy-saving signal. The second terminal apparatus determines, based on the identifier information and the resource configuration information, a resource for receiving the energy-saving signal, so that the second terminal apparatus may receive the energy-saving signal on a specified resource. The second terminal apparatus wakes up or goes to sleep based on the energy-saving signal, to reduce power consumption.

Abstract: A first terminal device determines a transmit power of a data channel, wherein the transmit power of the data channel comprise a first data channel part and a transmit power of a second data channel part, where the first data channel part is a part of the data channel that has a same time domain resource with a control channel, and the second data channel part is another part of the data channel that has a different time domain resource with the control channel. The first terminal device sends data in the first data channel part at the transmit power of the first data channel part, and sends data in the second data channel part at the transmit power of the second data channel part. This application may be applied to internet of vehicles, for example, V2X, LTE-V, and V2V.

Abstract: A communication method, a terminal apparatus, and a system. A first terminal apparatus and a second terminal apparatus determine, based on first configuration information, a plurality of candidate resources in a slot, and perform sidelink communication based on the candidate resources. A first symbol in any candidate resource in one slot is used to send first information. In response to a channel access moment of the first terminal apparatus being after a start moment of a first symbol in one candidate resource in a first slot, the first terminal apparatus further sends the first information based on the first symbol in another candidate resource after the channel access moment, without waiting for a next slot after the first slot. In this way, a sidelink communication delay is reduced.

Abstract: The present disclosure discloses example power control methods and apparatuses. One example method includes determining a transmit power of a control channel and a first data subchannel, where the control channel and the first data subchannel completely overlap in time domain and do not overlap in frequency domain. A transmit power of a second data subchannel is determined to be the same as the transmit power of the control channel and the first data subchannel, where the second data subchannel and the control channel overlap in frequency domain and do not overlap in time domain. The control channel and the first data subchannel are sent to a second terminal apparatus at the transmit power of the control channel and the first data subchannel. The second data subchannel is sent to the second terminal apparatus at the transmit power of the control channel and the first data subchannel.

Abstract: The method includes: A first terminal device determines a transmit power of a data channel, wherein the transmit power of the data channel comprise a first data channel part and a transmit power of a second data channel part, where the first data channel part is a part of the data channel that has a same time domain resource with a control channel, and the second data channel part is another part of the data channel that has a different time domain resource with the control channel. The first terminal device sends data in the first data channel part at the transmit power of the first data channel part, and sends data in the second data channel part at the transmit power of the second data channel part. This application may be applied to internet of vehicles, for example, V2X, LTE-V, and V2V.

Abstract: This application is applicable to the fields such as V2X, intelligent driving, and intelligent connected vehicles, and provides a communication method and system, and a terminal apparatus, to improve resource utilization. The method includes: A first terminal apparatus receives first sidelink information from a third terminal apparatus in a first slot. The first terminal apparatus determines an available time-frequency resource and/or an unavailable time-frequency resource in the first slot based on the first sidelink information. The first terminal apparatus sends first indication information to a second terminal apparatus, where the first indication information indicates the available time-frequency resource and/or the unavailable time-frequency resource in the first slot, and the first slot is a slot in which the second terminal apparatus sends second sidelink information.