Abstract: This application provides a precoding matrix transmission method and a communication apparatus. The method includes: A terminal device receives first configuration information, where the first configuration information is used to configure downlink transmission resources corresponding to K port groups, each of the K port groups includes a plurality of antenna ports, and K is a positive integer; and the terminal device sends precoding matrix indicator (PMI) information, where the PMI information indicates v groups of parameters, and any one of the v groups of parameters includes at least one first parameter, where the at least one first parameter corresponds to at least one of P groups of channel information, the P groups of channel information are determined based on a downlink reference signal received on the downlink transmission resources corresponding to the K port groups, v is a positive integer, and P is an integer greater than 1.

Abstract: A communication method and a related device, to reduce overheads in a channel measurement process, improving resource utilization and reducing power consumption of a terminal device. In the method, the terminal device receives a first reference signal, where the first reference signal corresponds to a first port set and a second port set, and each port set includes one or more ports. The terminal device sends first channel information and second channel information, where the first channel information is determined based on the first port set corresponding to the first reference signal and the second port set corresponding to the first reference signal, and the second channel information is determined based on the second port set corresponding to the first reference signal.

Abstract: In a random access method, random access preambles are grouped, and an electronic device selects a random access preamble from the grouped random access preambles, and receives an indication of a base station for the electronic device to send a message 3 repeatedly or in a diversity mode, so that the electronic device sends the message 3 repeatedly or in a diversity mode in a random access process. Accordingly, a probability of detecting the message 3 by the base station can be effectively improved, coverage performance of an uplink signal is improved, and/or resources of the base station are less wasted.

Abstract: This application provides a precoding matrix transmission method and a communication apparatus, to reduce overheads for feeding back channel information and reduce power consumption of a terminal device. The method includes: receiving first configuration information, where the first configuration information is for configuring resources of K port groups, each of the K port groups includes a plurality of antenna ports, and K is a positive integer; and sending first precoding matrix indicator (PMI) information, where the first PMI information is determined based on P groups of channel information, the P groups of channel information are determined based on a reference signal received on the resources of the K port groups, and P is an integer greater than 1.

Abstract: A backscatter communication method and apparatus provides operation including: receiving a first excitation signal from a first device; determining a first resource based on a candidate resource; and sending a backscattered signal of the first excitation signal to a second device based on the first resource. This can reduce a probability of selecting a same resource as another device to some extent, so that a conflict is reduced, and an access success rate of a backscatter device can be improved.

Abstract: A communication method and a related apparatus. The communication method includes determining, based on a starting location of a first remaining minimum system information RMSI detection window and a time index of a synchronization signal (SS)/physical broadcast channel (PBCH) block, a starting location of an RMSI detection window corresponding to a terminal device, where a value of the starting location of the RMSI detection window is one of four possible values of the starting location of the RMSI detection window, and receiving the RMSI based on the starting location of the RMSI detection window.

Abstract: This application provides a signal transmission method and apparatus, a reflector, and a receiver. In one example method, a reflector receives W excitation signals, where W exciters may be configured to carry data and a reference signal that are reflected by the reflector; and the reflector reflects data and L reference signals to a receiver, where the L reference signals are respectively carried in L excitation signals in the W excitation signals, where W and L are both integers greater than or equal to 1, and L is less than or equal to W.

Abstract: Example transmit power determining methods and apparatus are described. One example method includes determining a first transmit power based on N time domain resources corresponding to a first transport block. The first transport block is sent on the N time domain resources at the first transmit power. The first transmit power is a transmit power of the first transport block on each of the N time domain resources, a size of the N time domain resources is greater than one slot, and N is a positive integer.

Abstract: Methods, apparatuses, and storage media for transmitting a system information block are described. In an example implementation, a network device sends indication information to a terminal device. The terminal device determines a period of periodic transmission of a system information block (SIB) based on the received indication information, and receives, based on the period, a SIB1 sent by the network device. Alternatively, the terminal device determines a transmission location of aperiodic transmission of a system transport block based on the indication information, and receives, at the indicated transmission location, a SIB1 sent by the network device.

Abstract: A backscatter communication method and apparatus provides operation including: receiving a first excitation signal from a first device; determining a first resource based on a candidate resource; and sending a backscattered signal of the first excitation signal to a second device based on the first resource. This can reduce a probability of selecting a same resource as another device to some extent, so that a conflict is reduced, and an access success rate of a backscatter device can be improved.

Abstract: This application provides a relay transmission method, a communication apparatus, and a communication system. The method includes: A network device sends first information to a relay device. The first information is used to configure L time offsets and N relay beams. The network device sends second information to the relay device. The second information indicates L relay beams in the N relay beams and T pieces of time resource information that correspond to the L time offsets, and T?L. The relay device determines L time resources in L time units based on the L time offsets and the T pieces of time resource information. The relay device forwards a signal from the network device or a signal from a terminal device via the L relay beams and the L time resources. This can implement relay transmission of the signal on demand, and improve resource utilization.

Abstract: Embodiments of this application provide a power determining method, an apparatus, and a system, to resolve a problem of how to determine transmit power of sending a plurality of random access preambles. The method includes: determining first transmit power of N random access preambles to be sent to a network device, where the first transmit power is related to a quantity N of the random access preambles, and N is an integer greater than 1; and sending the N random access preambles to the network device at the first transmit power. This application is applicable to the field of communication technologies.

Abstract: This application relates to the field of communication technologies, and discloses a communication method and apparatus. On example method includes: a backscatter device receives an excitation signal from an exciter. The backscatter device determines a backscatter signal pattern in a backscatter signal pattern set, where the backscatter signal pattern set includes a plurality of backscatter signal patterns, and backscatter reference signals in the plurality of backscatter signal patterns do not overlap in time domain. The backscatter device modulates a backscatter reference signal and a backscatter data signal on the excitation signal based on the determined backscatter signal pattern, to obtain a backscatter signal. The backscatter device sends the backscatter signal to a receiver.

Abstract: Embodiments of this application disclose a synchronization signal block determining method and a related apparatus. The method includes: A terminal device detects a first synchronization signal block (SSB); the terminal device determines a second SSB based on the first SSB, where a frequency domain position of the first SSB and a frequency domain position of the second SSB are within a preset bandwidth, or a difference between frequency domain positions of the first SSB and the second SSB is a preset value. The second SSB may be considered as a backup SSB for the first SSB.

Abstract: This application discloses a resource configuration method and an apparatus. The method includes: obtaining, by a terminal device, configuration information, where the configuration information includes at least one piece of the following information: random access resource configuration information and downlink signal parameter information; and accessing, by the terminal device, a network device based on the configuration information. A corresponding apparatus is also disclosed.

Abstract: This application provides a signal transmission method and apparatus, a reflector, and a receiver. In one example method, a reflector receives W excitation signals, where W exciters may be configured to carry data and a reference signal that are reflected by the reflector; and the reflector reflects data and L reference signals to a receiver, where the L reference signals are respectively carried in L excitation signals in the W excitation signals, where W and L are both integers greater than or equal to 1, and L is less than or equal to W.

Abstract: This application discloses a communications method and apparatus. The method includes: sending, by a terminal device, a first message to a network device, where the first message includes a first random access preamble and first data, and a first redundancy version is used for the first data; and determining, by the terminal device, that the first data fails to be sent, and retransmitting the first data, where a second redundancy version is used for the first data. The corresponding communications apparatus is further disclosed. An incremental redundancy manner is used in a retransmission procedure of random access data.

Abstract: This disclosure discloses a communication method and apparatus. In the method, a reflector is used to assist in communication between a terminal and an access network device, and in a reflector-assisted communication process, the reflector is indicated to be in a working mode when being required by the terminal or the access network device, to assist in communication, and the reflector is indicated to be in a sleep mode when being required by the terminal or the access network device, to reduce power consumption.

Abstract: This application relates to the field of communication technologies, and discloses a communication method and apparatus. On example method includes: a backscatter device receives an excitation signal from an exciter. The backscatter device determines a backscatter signal pattern in a backscatter signal pattern set, where the backscatter signal pattern set includes a plurality of backscatter signal patterns, and backscatter reference signals in the plurality of backscatter signal patterns do not overlap in time domain. The backscatter device modulates a backscatter reference signal and a backscatter data signal on the excitation signal based on the determined backscatter signal pattern, to obtain a backscatter signal. The backscatter device sends the backscatter signal to a receiver.

Abstract: This application provides a random access preamble transmission method and an apparatus. In one example method, a terminal receives indication information, wherein the indication information indicates a difference; the terminal sends a random access preamble, wherein a transmit power of the random access preamble is determined based on the difference, an expected receive power, a path loss for transmitting a synchronization signal block (SSB), and a maximum transmit power of the terminal.