Abstract: A sending device may obtain a first to-be-encoded vector. The sending device may perform first encoding on the first to-be-encoded vector, to obtain a second to-be-encoded vector. The sending device may encode the second to-be-encoded vector based on a first generator matrix, to obtain an encoded codeword. The first generator matrix may include at least N+1 submatrices a, and N of the submatrices a may be located on a main diagonal of the first generator matrix. The first generator matrix may be a block upper triangular matrix, or the first generator matrix may be a block lower triangular matrix. The submatrix a is a polar kernel matrix with a size of 2m*2m, m is a natural number, and N is a natural number. The sending device may send the encoded codeword.

Abstract: An encoding method includes obtaining to-be-encoded information and a mother code length N. The to-be-encoded information includes K information bits. The method also includes determining, based on K and N, a set I corresponding to subchannels of the information bits and a set F corresponding to subchannels of frozen bits. Information bits corresponding to subchannel sequence numbers in the set I are distributed in X outer component codes, a code length of each outer component code is B, and the X outer component codes includes a first-type outer component code and a second-type outer component code or the X outer component codes include a first-type outer component code, a second-type outer component code, and one third-type outer component code. Different types of component codes have different code rates. The method additionally includes performing polarization encoding based on the set I and the set F.

Abstract: An encoding method and apparatus, a decoding method and apparatus, and a device are provided. The encoding method includes obtaining K to-be-encoded bits (S301), where K is a positive integer; determining a first generator matrix, where the first generator matrix includes at least two sub-blocks distributed based on a preset position relationship, and the sub-block includes a plurality of first generator matrix cores (S302); generating a second generator matrix based on the first generator matrix, where the second generator matrix includes T sub-blocks, and a position relationship between two adjacent sub-blocks of the T sub-blocks is determined based on the preset position relationship (S303), where T is a positive integer; and polar encoding the K to-be-encoded bits based on the second generator matrix (S304), to obtain encoded bits. This reduces encoding/decoding complexity.

Abstract: An encoding method and apparatus are provided, to propose a construction and encoding scheme of a BCH code. A code length and a code rate of an obtained BCH code are flexible, to satisfy a requirement of flexible channel encoding in wireless communication. The method includes determining a first encoding parameter based on a first BCH code, where the first BCH code is a to-be-coded BCH code, the first encoding parameter is a first code or a generator matrix of a first code, the first code has a code length of n and an information bit length of k, n is greater than 0, and k is greater than 0, and performing BCH encoding based on the first encoding parameter.

Abstract: This application provides a rate matching method, including: A transmitter obtains a to-be-coded bit sequence; the transmitter performs polar coding on the to-be-coded bit sequence, to obtain a first bit sequence, where a length of the first bit sequence is N; the transmitter performs first rate matching on the first bit sequence, to obtain a second bit sequence, where a length of the second bit sequence is E1; the transmitter sends the second bit sequence; the transmitter performs polar coding based on the to-be-coded bit sequence, to obtain a third bit sequence, where a length of the third bit sequence is 2*N; the transmitter performs second rate matching on the third bit sequence, to obtain a fourth bit sequence, and the transmitter sends the fourth bit sequence, where N, E1 are positive integers.

Abstract: A communication method and apparatus is provided so that a fading channel can implement a good error correction capability. This helps improve information transmission reliability. The method includes: a transmit end device determines, based on N bit sets, a first sequence and a second sequence that are obtained through quadrature amplitude modulation QAM. The first sequence includes N in-phase components, and the second sequence includes N quadrature components; or the first sequence includes N quadrature components, and the second sequence includes N in-phase components, where N is an integer greater than or equal to 2. Then, the transmit end device performs interleaving processing on the first sequence, to obtain a third sequence. Then, the transmit end device sends, to a receive end device, a symbol sequence determined based on the second sequence and the third sequence. The symbol sequence includes N QAM symbols.

Abstract: Embodiments of this application disclose a channel coding method and apparatus. The method includes: obtaining a subsequence based on a first sequence and a second sequence; and determining a generator polynomial or a generator matrix based on the subsequence, where the generator polynomial or the generator matrix is used for cyclic code encoding. According to embodiments of this application, generator polynomials or generator matrices for channel coding of different lengths and different bit rates are determined by using two sequences, so that storage space is reduced, and storage complexity is reduced.

Abstract: A decoding method includes: decoding first to-be-decoded information based on a first decoder to obtain a first decoding result that includes first soft information or a first hard output; and correcting the first decoding result based on a first correction model to obtain a corrected first decoding result of the first to-be-decoded information. The first correction model is obtained through training based on training data that includes a training decoding result and a corrected training decoding result. The training decoding result is a decoding result obtained after the first decoder decodes training to-be-decoded information, and the corrected training decoding result is a corrected decoding result corresponding to the training decoding result. In this way, after a decoder performs decoding, a decoding result can be corrected based on a correction model.

Abstract: This application provides a data sending method and an apparatus. The method includes: A first device sends, to a second device, first data modulated by using a first quadrature amplitude modulation codebook. The second device receives, from the first device, the first data modulated by using the first quadrature amplitude modulation codebook. When the second device fails to decode the first data modulated by using the first quadrature amplitude modulation codebook, the first device sends, to the second device, second data modulated by using a second quadrature amplitude modulation codebook. The second data is a part or all of the first data, and the first quadrature amplitude modulation codebook is different from the second quadrature amplitude modulation codebook. The second device receives, from the first device, the second data modulated by using the second quadrature amplitude modulation codebook, and jointly decodes the first data and the second data.

Abstract: Embodiments of this application disclose a example polar code encoding methods, example polar code decoding methods, and example apparatuses thereof. One example method in embodiments of this application includes generating an input vector, where the input vector includes T subblocks, a first information bit of a first subblock is obtained by replicating a second information bit of a second subblock, the first subblock and the second subblock are subblocks of the T subblocks, a sequence number of the first subblock is after a sequence number of the second subblock, and T is an integer greater than or equal to 2. Polar encoding can then be performed on the input vector to obtain an encoded bit.

Abstract: The technology of this application relates to an information processing method and a communication apparatus, to reduce implementation complexity of a distribution matcher, and improve encoding efficiency. The method includes obtaining information bits, where the information bits include K bits, and K is a positive integer. The method further includes mapping the information bits to a target symbol sequence based on a trellis diagram, where the target symbol sequence includes M symbols, M is a positive integer greater than K, the M symbols include m symbols whose values are first values, the trellis diagram includes at least M directed edges, and one directed edge corresponds to a value of one symbol in the target symbol sequence.

Abstract: A method for preparing low-background cement includes: uniformly mixing a seed crystal of cement, C4AF whiskers, and high-magnesium raw material to yield a first mixture, calcining the first mixture at 1400-1500° C., to yield a low-background clinker, the first mixture including 1.0-5.0 wt. % of the seed crystal of cement, 1.0-5.0 wt. % of the C4AF whiskers, and the balance is the high-magnesium raw material; and grinding a second mixture of the low-background clinker and gypsum, to yield low-background cement. The seed crystal of cement is a high-magnesium and low hydration heat clinker, has a specific activity of Ra-226 radioactive nuclides within 50 Bq/kg, and the MgO content of the clinker is between 4.0 wt. % and 5.0 wt. %, with 50 wt. %?C3S?55.0 wt. %; and the high-magnesium raw material has a MgO content between 2.5 wt. % and 3.0 wt. %.

Abstract: A coding method and apparatus are provided. The method includes: obtaining a to-be-coded sequence whose length is N, after an information bit is placed at an information bit position, wherein first preset bits are placed at shaping bit positions in a first position sequence, and shaping bit positions whose corresponding bits after polar coding belong to a same subcode of inner code belong to a same group; performing outer code coding on the to-be-coded sequence, to obtain a first outer code sequence whose length is N, based on which first outer code codeword bits corresponding to shaping bit position groups are obtained; obtaining a target outer code sequence based on the first outer code sequence and the first outer code codeword bits; and performing inner code coding on the target outer code sequence, to obtain and output a coded sequence. Probability amplitude shaping (PAS) coding latency can be reduced.

Abstract: An encoding method, a decoding method, and a communication apparatus. The communication apparatus obtains an information bit sequence with a length K. A length K1 of a first sequence based on K or M is determined, where M is a quantity of modulation symbols. A first vector is obtained based on K, K1, and a predefined sequence. A length of the first vector is 2JM, J is a modulation order, the first vector indicates J coding sub-blocks, the J coding sub-blocks separately belong to a first-type sub-block including at least one coding sub-block or a second-type sub-block including at least one coding sub-block. The communication apparatus determines frozen bit locations in the first-type sub-block and information bit locations in the second-type sub-block and encodes the information bit sequence based on the frozen bit locations in the first-type sub-block, the information bit locations in the second-type sub-block, and the first vector.

Abstract: This application discloses an encoding method, a decoding method, and an apparatus. The encoding method includes: obtaining a first bit sequence and a target code length M; then performing first channel encoding on the first bit sequence, to obtain a second bit sequence; performing second channel encoding based on the second bit sequence, to obtain a third bit sequence; and outputting the third bit sequence. The first bit sequence includes K information bits, the second bit sequence includes N bits, and the third bit sequence includes the N bits and E check bits, where M>N, and E=M?N. M, K, N, and E are all integers greater than or equal to 1.

Abstract: This application discloses a retransmission method and an apparatus. The method includes: obtaining a first bit sequence and a number E of to-be-retransmitted bits, performing second channel encoding based on the first bit sequence to obtain a second bit sequence, and performing retransmission based on the second bit sequence. The first bit sequence is obtained by performing first channel encoding based on K information bits, a length of the first bit sequence is N, N, E, and K are all integers greater than or equal to 1, and the second bit sequence includes the E to-be-retransmitted bits. According to the method, a code length can be flexibly extended based on different numbers E of to-be-retransmitted bits.

Abstract: A polar code construction method and an apparatus. A communication apparatus obtains a reliability weight sequence, and determines a first threshold that indicates a weight of lowest reliability of a subchannel corresponding to an information bit. The communication apparatus determines a non-pre-frozen subchannel corresponding to a content value greater than or equal to the first threshold in the reliability weight sequence as the subchannel corresponding to the information bit based on the first threshold, and performs polar coding on the information bit based on the subchannel corresponding to the information bit.

Abstract: An encoding method, a decoding method, and an apparatus. A symbol quantity S is determined based on an encoding bit quantity L and an energy level quantity B, where S is S1 or S2, S1=L/B, and S2=L/2B. K information sub-channels are determined from an encoding sequence based on the symbol quantity S, the energy level quantity B, and a reliability sequence. K information bits are encoded and a bit sequence is output based on the K information sub-channels, where the K information sub-channels are selected from candidate sub-channels based on an order of reliability of the candidate sub-channels. The candidate sub-channels are S1 sub-channels or 2×S2 sub-channels in a sub-sequence whose energy level is i in the encoding sequence.

Abstract: This application provides a communication method and apparatus, and is applicable to the field of communication technologies, such as NR and LTE, to improve flexibility and diversity of channel coding, and improve communication performance and security. The method includes: A first device performs channel encoding on first data based on a generator matrix to obtain second data, and sends the second data to a second device. At least some parameters in the generator matrix are determined based on a random seed, and the random seed is determined based on one or more of the following: a channel encoding parameter, a parameter of the first device, or a parameter of the second device.

Abstract: A polar code construction method and an apparatus. A communication apparatus obtains a reliability weight sequence, and determines a first threshold that indicates a weight of lowest reliability of a subchannel corresponding to an information bit. The communication apparatus determines a non-pre-frozen subchannel corresponding to a content value greater than or equal to the first threshold in the reliability weight sequence as the subchannel corresponding to the information bit based on the first threshold, and performs polar coding on the information bit based on the subchannel corresponding to the information bit.