Abstract: Example beam hopping methods and apparatus are described. In one example method, a first satellite sends a communication signal to a first area by using a first beam, where the communication signal is used by the first satellite to communicate with a terminal device in the first area, and the first area belongs to an area covered by the first satellite. The first satellite sends a positioning signal to a second area by using a second beam, where the positioning signal is used by a terminal device in the second area for positioning measurement.

Abstract: Embodiments of this application provide a channel matrix determining method, an apparatus, and a system, relating to the field of communication technologies, to resolve a technical problem that a manner in which a network device determines a precoding matrix based on an existing PMI indicator is not applicable to long-distance communication. The method includes: A terminal device obtains a plurality of reference signals, determines a first channel matrix based on the plurality of reference signals, and feeds back, to a network device, first information indicating some channel elements in the first channel matrix. The terminal device may further receive a downlink signal determined based on the first information and sent by the network device. A channel element in the some channel elements is determined based on signal strength and/or a time-frequency resource of the reference signal.

Abstract: This application relates to the field of communication technologies, and provides a precoding method and a communication apparatus. The method includes: A terminal device obtains a first reference signal, where the first reference signal is a reference signal precoded by using a first precoding matrix. Then the terminal device sends first information, where the first information is determined based on a measurement result of the first reference signal, and is used to determine a target precoding matrix. Then the terminal device obtains information precoded by using the target precoding matrix.

Abstract: Example methods and apparatus for determining a timing advance are described. One example method includes obtaining ephemeris information of a satellite, where the ephemeris information includes coordinates of the satellite and an ephemeris error of the satellite. A timing advance is determined according to a preset rule based on the ephemeris information and location information of a terminal device, where the location information includes coordinates of the terminal device and a positioning error of the terminal device. The preset rule is determined by using a first horizontal distance, a first vertical distance, the ephemeris error, and the positioning error.

Abstract: A bandwidth part switching method, is applicable to a non-terrestrial network (NTN) to implement BWP switching based on multi-color frequency-division multiplexing. In the method, a terminal device may report, in a second BWP to a network device, an index of a first SSB whose signal quality is greater than or equal to a first threshold in one or more SSBs in a first BWP, and switch from the second BWP to a third BWP. The one or more SSBs correspond to at least one BWP other than the first BWP, and the third BWP is in the at least one BWP and corresponds to the first SSB. After receiving the index of the first SSB in the second BWP, the network device determines the third BWP, and performs service data transmission with the terminal device in the third BWP.

Abstract: A terminal apparatus receives a parameter that is configured by a network apparatus and that is used to calculate an update period, where the update period is used to indicate time at which the terminal apparatus receives an uplink time-frequency synchronization parameter. The terminal apparatus receives an updated uplink time-frequency synchronization parameter based on the update period. The network apparatus configures the parameter for calculating the update period, so that the terminal apparatus can update the uplink time-frequency synchronization parameter in time.

Abstract: Example frequency compensation methods and apparatus are described. One example method includes determining first information and sending the first information by a network device to a terminal device, where the first information indicates a frequency compensation manner of an uplink signal of the terminal device or the first information indicates a configuration parameter of the terminal device. The terminal device receives the first information, and determines, based on the first information, the frequency compensation manner to be used to send the uplink signal. The terminal device performs frequency compensation for the uplink signal based on the frequency compensation manner.

Abstract: This application provides example beam management methods, apparatus, and systems. In one example method, a terminal device can receive indication information from a network device. The terminal device can perform beam switching according to an arrangement order of transmission configuration indicator (TCI) states (TCI-states) in a second TCI list when the indication information is first indication information. Alternatively, the terminal device can perform beam switching according to a first TCI-state in a first TCI list when the indication information is second indication information, wherein the first TCI list comprises a plurality of TCI-states comprising the first TCI-state, and in the first TCI list, beams corresponding to TCI-states after the first TCI-state are to sequentially provide a service for the terminal device.

Abstract: Embodiments of this application provide a timing offset parameter update method, a device, and a system, and relate to the field of communication technologies, to help reduce signaling overheads generated when a network device updates a value of a timing offset parameter. The method includes: A terminal device obtains first information that includes a first reference value and first indication information, where the first indication information indicates an update rule of a timing offset parameter, and the first reference value is an initial value of the timing offset parameter. The terminal device updates a value of the timing offset parameter based on the first information and a timing offset variation, to obtain an updated value of the timing offset parameter, where an absolute value of the timing offset variation is equal to an absolute value of a difference between any two consecutively updated values of the timing offset parameter.

Abstract: Embodiments of this application relate to the field of communication technologies, and provide a timing offset parameter update method, a device, and a system, to help reduce signaling overheads when a terminal device updates a value of a timing offset parameter. The method includes: A terminal device obtains a timing advance adjustment variation corresponding to the terminal device, where the timing advance adjustment variation is a difference between a timing advance adjustment amount currently used by the terminal device and a timing advance adjustment amount used at a previous moment. The terminal device determines whether an absolute value of the timing advance adjustment variation is greater than or equal to a first threshold. If the absolute value is greater than or equal to the first threshold, the terminal device sends, to a network device, first indication information used to indicate an update regularity of a timing offset parameter.

Abstract: A side information transmission method and apparatus, where data to be transmitted by a transmit end includes at least one first data sub-block and at least one second data sub-block. A first modulated signal is obtained based on a first phase rotation factor. A second modulated signal is obtained based on a second phase rotation factor. Side information is generated based on the first phase rotation factor and the second phase rotation factor. The first data sub-block is carried on a first subcarrier, and the side information is also mapped to the first carrier. The first modulated signal corresponding to the at least one first data sub-block, the second modulated signal corresponding to the at least one second data sub-block, and a modulated signal corresponding to the side information are superposed to obtain a to-be-transmitted signal.

Abstract: This application discloses a data transmission method, apparatus, and system. The method includes: generating a to-be-sent bit sequence, where the to-be-sent bit sequence includes one or more bits in a bit sequence having a length of (N?M), where N is a length of a mother code for polar encoding, M is a length of encoded bits obtained after rate matching is performed on a bit sequence having a length of N, N is m raised to the power of an integer, m is a positive integer greater than 1, M is a positive integer, and N>M; and sending the generated bit sequence. A corresponding apparatus and system are further disclosed. In this application, in this data transmission solution, an additional coding gain is generated during decoding, so that a decoding FER is reduced, and decoding performance is improved.

Abstract: This application provides a satellite communication method and apparatus. A terminal obtains a level-1 broadcast signal from a satellite, where a beam status corresponding to the level-1 broadcast signal is an energy saving state, and the level-1 broadcast signal includes synchronization information. The terminal obtains a level-2 broadcast signal from the satellite, where a beam status corresponding to the level-2 broadcast signal is a broadband communication state. The terminal communicates with the satellite based on the level-2 broadcast signal.

Abstract: Embodiments of the application provide a method for rate matching in a wireless communication network. A device obtains K information bits and a target code length M of a polar code, determines, according to a minimum value of a set of values, a mother code length N1, polar encodes the K information bits to obtain an encoded sequence of N1 bits, obtains a target sequence of M bits from the N1 bit encoded sequence, and outputs the M-bit target sequence. When the mother code length N1 is larger than the target code length M, (N1?M) bits of the encoded sequence are punctured or shortened from the N1 bit encoded sequence.

Abstract: This application provides a communication method and apparatus, and relates to the field of communication technologies. According to the method, the terminal device determines a location of an NTN device in an NTN. The method includes: A network device sends system information to the terminal device. The system information includes a location parameter of a non-terrestrial network NTN device, and the system information is used to indicate time information of the location parameter.

Abstract: Examples in this application provide a wireless communication method and device. One example method includes obtaining downlink control information and a scrambled sequence from a network device, where bits corresponding to the scrambled sequence are scrambled with each piece of configuration information of a plurality of pieces of configuration information used for configuring a terminal device by the network device, each piece of the configuration information corresponds to at least one bit in the scrambled sequence, and at least one bit of the bits that correspond to each piece of the configuration information does not correspond to another piece of configuration information of the plurality of pieces of the configuration information, descrambling, based on a possible value of each piece of the configuration information, the bits corresponding to each piece of the configuration information, to obtain a descrambled sequence, and performing a check operation using the descrambled sequence and the DCI.

Abstract: This application provides a communication method and apparatus and a computer-readable storage medium. The method includes: receiving one or more synchronization information blocks SSBs; determining, based on a first SSB and/or a second SSB, a network type corresponding to the one or more SSBs; and determining an access network based on the network type. According to technical solutions provided in this application, a network type of an access network can be accurately identified in a frequency sweep stage.

Abstract: This application discloses random access methods and communication apparatuses, and relates to the field of communication technologies. In an example method, after determining a correspondence between scanning periods of different scanning areas within coverage of a synchronization signal block (SSB) beam and random access occasions (ROs), a second communication apparatus sends, through broadcasting, a first message including information about the correspondence. A first communication apparatus receives the first message, determines an RO based on a scanning area in which the first communication apparatus is located and the first message, and initiates random access.

Abstract: This application provides a signal transmission method and an apparatus. A network device broadcasts a navigation reference signal and a communication signal. A terminal device may determine its position information based on the navigation reference signal. A communication sequence in the communication signal and a navigation sequence in the navigation reference signal are coupled by using a same even-number-stage m-sequence, so that the terminal device is supported in completing an integrated communication and navigation function based on the broadcast signal.

Abstract: This application provides an uplink timing method. A half-duplex terminal device determines, based on a maximum timing advance of an area in which the terminal device is located and a set of time units used by the terminal device to receive a system message, a set of time units unavailable for uplink transmission, and in a process of calculating a time unit for sending an uplink signal, skips, based on a scheduling offset of the uplink signal, a time unit in the set of time units unavailable for uplink transmission, to avoid a problem that the half-duplex device needs to simultaneously perform receiving and sending in a large transmission latency scenario.