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: 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: 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 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.

Abstract: Embodiments of this application provide a communication method and apparatus. In the method, a terminal device receives a first signal, and detects F frames of the first signal to obtain a first resource. F may be a multiplexing factor, such as a frequency/polarization multiplexing factor. The terminal device performs detection based on a frame number of the first resource to obtain a second resource. The first resource and the second resource may be a same resource.

Abstract: The technology of this application relates to a random access method, applied to the communication field. The method includes a terminal device sends, to a network device, a first message used to establish a wireless connection, the terminal device receives, a connection response sent by the network device, where the connection response includes information about a first polarization parameter, and when accessing the network device based on the connection response, the terminal device determines, based on the information about the first polarization parameter included in the connection response, whether the terminal device is qualified to access the network device. A dimension, namely, a polarization parameter, is introduced into a random access procedure, so that a preamble capacity is increased, a problem that the network device cannot identify a colliding terminal device is alleviated, and efficiency of establishing a communication connection between the terminal device and the network device is improved.

Abstract: A communication method and apparatus are provided, and relate to the field of wireless communication technologies, to resolve a problem in a conventional technology that communication quality during communication between a satellite and a communication apparatus cannot be ensured, and to ensure security of high-accuracy location information of the satellite. In the method, the communication apparatus may perform random access to the satellite based on first location information. The communication apparatus may perform uplink communication with the satellite based on obtained second location information. Accuracy of a location obtained based on the second location information is higher than accuracy of a location obtained based on the first location information. Based on this solution, required accuracy of location information of the satellite is different.

Abstract: A method and a communication apparatus for determining a timing advance. A downlink signal is received from a network device. A first reference moment of a signal period of the downlink signal is determined, where the first reference moment includes a start receiving moment of the signal period. A first time interval between the start receiving moment and a start moment of a first period in which the terminal is located is determined. Based on the first time interval, determining whether a start sending moment of the signal period is within the first period, and determining the start sending moment, where a period is a duration distributed at an equal interval on a time axis. A timing advance is determined based on the start receiving moment and the start sending moment, and an uplink signal is sent based on the timing advance.

Abstract: A gateway station switching method and apparatus. When quality of a link from a terminal device to a source gateway station through a satellite is poor, the source gateway station sends third indication information to a target gateway station, so that the target gateway station feeds back second channel quality to the source gateway station, that is, quality of a link from the terminal device to the target gateway station through the satellite. The source gateway station determines, based on the second channel quality and first channel quality that represents the quality of the link from the terminal device to the source gateway station through the satellite, whether to switch the terminal device to the target gateway station.

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 method and an apparatus for updating a timing offset, and is particularly applicable to an NTN network such as satellite communication. The terminal side method includes: A terminal receives a timing offset difference ?Koffset, and updates a timing offset based on the ?Koffset to obtain an updated timing offset. The network side method includes: A network device determines a timing offset difference ?Koffset, and sends the ?Koffset to a terminal device, wherein the ?Koffset is used for the terminal device to update a timing offset.

Abstract: Embodiments of this application provide a timing advance determining method and a communication apparatus, to improve precision of calculating a timing advance (Timing Advance, TA) by a terminal, and reduce inter-symbol interference (Inter-Symbol Interference, ISI). The method includes: A first network device determines a first parameter based on a first delay compensation value, where the first delay compensation value is delay compensation made by the first network device for receiving a signal sent by a terminal, the first parameter indicates a difference between a round-trip delay of a feeder link in a non-terrestrial network NTN and the first delay compensation value, and the difference is used to determine a TA used by the terminal for signal sending; and the first network device sends the first parameter.