Abstract: This application provides a data transmission method, a base station, and a terminal device. The method includes: determining, by a base station, a target base graph in N Raptor-like low-density parity-check (LDPC) base graphs; and sending, by the base station, indication information to a terminal device, where the indication information is used to indicate the terminal device to use the target base graph to perform LDPC encoding and decoding. Based on the foregoing technical solution, the base station may determine a target base graph in a plurality of Raptor-like LDPC base graphs that may be used to perform LDPC encoding and decoding, and indicate the target base graph to the terminal device. Further, for one code rate or one code length, the base station may select different base graphs as required.

Abstract: This application provides a data processing method and a data processing apparatus. The data processing method includes: determining C code blocks, where C is a positive integer; and dividing the C code blocks into K code block groups, where an absolute value ?C of a difference between quantities of code blocks included in any two of the K code block groups is less than or equal to a first threshold, and K is a positive integer. The data processing method and the data processing apparatus provided in this application help lower a bit error rate.

Abstract: This application relates to communicating information between communication devices. A channel coding method is disclosed. A communication device obtains an input sequence of K bits. The communication device encodes the input sequence using a low density parity check (LDPC) matrix H, to obtain an encoded sequence. The LDPC matrix H is determined according to a base matrix and a lifting factor Z. The base matrix includes m rows and n columns, m is greater than or equal to 5, and n is greater than or equal to 27. The lifting factor Z satisfies a relationship of 22*Z?K. According to the encoding method provided in the embodiments, information bit sequences of a plurality of lengths can be encoded for transmission between the communication devices.

Abstract: Embodiments of the present invention disclose an information processing method and apparatus, and a device. The method includes: if Rreal is greater than or equal to Rmin, determining, based on a maximum code block length Kmax of an LDPC (low-density parity-check code) code, a quantity C of code blocks into which a transport block is to be segmented, where Rreal is a largest one among an encoding code rate of the transport block, a code rate limit of the transport block, and a minimum code rate of the LDPC code, and Rmin is a minimum code rate corresponding to the maximum code block length of the LDPC code, or a larger one between a minimum code rate corresponding to the maximum code block length of the LDPC code and a code rate limit of the maximum code block length of the LDPC code.

Abstract: An information processing method, an apparatus, a communications device, and a communications system are provided. The communications device is configured to: obtain a starting position in a buffer sequence W for an output bit sequence, and determine the output bit sequence from the buffer sequence W based on the starting position, where a value of the starting position is one element in {p0, p1, p2, . . . , pkmax?1}, 0?k<kmax, 0?pk<NCB, pkis an integer, k is an integer, NCB is a length of the buffer sequence W, kmax is an integer greater than or equal to 4, and there are two or more different neighboring intervals in {p0, p1, p2, . . . , pkmax?1}. A bit sequence for initial transmission or retransmission is properly determined, so that decoding performance of a communications device on a receive end after receiving the bit sequence is improved, a decoding success rate is enhanced, and a quantity of retransmission times is further reduced.

Abstract: This application provides a data processing method, a data processing apparatus, and a communications device. The data processing method includes: coding a first bit sequence, to obtain a second bit sequence, where the first bit sequence includes a first information bit and a first padding bit, and the second bit sequence includes a second information bit and a redundant bit; and storing the second bit sequence in a circular buffer.

Abstract: Embodiments of this application provide a communications method and apparatus. The method includes: obtaining an input sequence for rate matching, wherein the input sequence is a retransmission sequence corresponding to a transport block, the input sequence comprises M code block groups, a value of M is less than a quantity of code block groups obtained after the transport block is segmented, and the M code block groups comprise Ct code blocks; and performing rate matching on the Ct code blocks, wherein a length of a rate matching output sequence of of each of the Ct code blocks satisfies the following conditions: when j?Ct???1, E=NL·Qm·?G?/Ct?; when j>Ct???1, E=NL·Qm·?G?/Ct?. The method may be applicable to a system in which transmission is performed based on a code block group, and resources are fully used as many as possible, thereby improving performance.

Abstract: This application provides a data processing method and a communications device. The data processing method includes: determining, by a first communications device, NCB, based on a size of the circular buffer of the communications device and an information processing capability of a second communications device; and obtaining, by the first communications device, a second encoded bit segment from a first encoded bit segment having a length of NCB. According to the data processing method and the communications device provided in this application, decoding complexity of the communications device can be reduced and communication reliability can be improved.

Abstract: Embodiments of this application disclose a data processing method and a data processing device. The method includes: obtaining a first to-be-processed bit sequence, where the first to-be-processed bit sequence is a transport block or a code block generated by performing code block segmentation on a transport block; encoding the first to-be-processed bit sequence to obtain a first encoded bit sequence; storing all or at least some bits of the first encoded bit sequence into a circular buffer; and outputing a first output bit sequence from the bits stored in the circular buffer. According to the method and the device that are provided in this application, rate matching can be implemented for a sequence generated through LDPC encoding.

Abstract: The present disclosure relates 10 encoding methods, communication methods and apparatus. In one example method, a first information sequence is encoded by using a first matrix to obtain a second information sequence, where the first matrix meets a function related to a lifting factor and an element in Emax(H). The second information sequence is outputted.

Abstract: A low density parity check (LDPC) channel encoding method for use in a wireless communications system includes a communication device encoding an input bit sequence by using a LDPC matrix to obtain an encoded bit sequence for transmission. The LDPC matrix is obtained based on a lifting factor Z and a base matrix. The encoding method can be used in various communications systems including the fifth generation (5G) telecommunication systems, and can support various encoding requirements for information bit sequences with different code lengths.

Abstract: This application relates to communicating information between communication devices. A channel coding method is disclosed. A communication device obtains an input sequence of K bits. The communication device encodes the input sequence using a low density parity check (LDPC) matrix H, to obtain an encoded sequence. The LDPC matrix H is determined according to a base matrix and a lifting factor Z. The base matrix includes m rows and n columns, m is greater than or equal to 5, and n is greater than or equal to 27. The lifting factor Z satisfies a relationship of 22*Z?K. According to the encoding method provided in the embodiments, information bit sequences of a plurality of lengths can be encoded for transmission between the communication devices.

Abstract: An information processing method, an apparatus, a communications device, and a communications system are provided. The communications device is configured to: obtain a starting position in a buffer sequence W for an output bit sequence, and determine the output bit sequence from the buffer sequence W based on the starting position, where a value of the starting position is one element in {p0, p1, p2, . . . , pkmax?1}, 0?k<kmax, 0?pk<NCB, pk is an integer, k is an integer, NCB is a length of the buffer sequence W, kmax is an integer greater than or equal to 4, and there are two or more different neighboring intervals in {p0, p1, p2, . . . , pkmax?1}. A bit sequence for initial transmission or retransmission is properly determined, so that decoding performance of a communications device on a receive end after receiving the bit sequence is improved, a decoding success rate is enhanced, and a quantity of retransmission times is further reduced.

Abstract: This application discloses a data transmission method, a sending device, a receiving device, and a communications system. The sending device is configured to send a first transport block. The sending device obtains a coded bit segment from a first encoded code block. The first encoded code block is obtained after LDPC encoding is performed on a first code block in the first transport block based on a processing capability of the receiving device. The sending device sends the coded bit segment to the receiving device. Because the processing capability of the receiving device is considered, storage overheads of the sending device or the receiving device can be reduced, encoding or decoding complexity can be reduced, and a decoding success rate can be improved.

Abstract: Embodiments of this application provide a communications method and apparatus. The method includes: obtaining an input sequence of rate matching, wherein the input sequence is a retransmission sequence corresponding to a transport block, the input sequence comprises M code block groups, a value of M is less than a quantity of code block groups obtained after the transport block is segmented, and the M code block groups comprise Ct code blocks; and performing rate matching on the Ct code blocks, wherein a length of an output sequence of rate matching of each of the Ct code blocks satisfies the following conditions: when j?Ct???1, E=NL·Qm·?G?/Ct?; when j>Ct???1, E=NL·Qm·?G?/Ct?. The method may be applicable to a system in which transmission is performed based on a code block group, and resources are fully used as many as possible, thereby improving performance.

Abstract: The present disclosure relates to a communications field, and discloses a method for generating a base matrix of an LDPC code, an encoding/decoding method, and a device, to resolve a problem that a probability of a decoding error increases because performance of a transformed check matrix cannot be ensured due to a poor puncturing pattern. A specific solution is as follows: A size of a check bit part of a base matrix is determined based on a required minimum bit rate, and the check bit part of the base matrix is determined based on the size of the check bit part and an initial matrix. The initial matrix is a matrix with a size of m×m that has a bidiagonal structure, the check bit part is a k-order transformation matrix Hk obtained after the initial matrix is transformed k times, k meets 2k?1m<T?2km, and T is the size of the check bit part.

Abstract: Systems, methods, and non-transitory computer-readable media can generate a set of candidate content items from a plurality of content items that are available in the social networking system, wherein one or more of the candidate content items are to be included in a personalized content stream for a first user. A corresponding score for each of the candidate content items can be generated with respect to the first user. A first set of content items can be determined from the set of candidate content items based at least in part on the respective scores, wherein content items in the first set are included in the personalized content stream.

Abstract: The present disclosure relates to methods and apparatuses for generating a low-density parity-check code basis matrix. One example method includes obtaining a low-density parity-check code mother matrix, and generating a 1st matrix to a qth matrix one by one, where q is a preset positive integer. A Pth matrix in the 1st matrix to the qth matrix is generated in the following manner: selecting a to-be-replaced matrix element in a (P?1)th matrix, where the to-be-replaced matrix element is a matrix element having a value that is not ?1 in the (P?1)th matrix, determining a Pth shift factor corresponding to the to-be-replaced matrix element, and replacing the to-be-replaced matrix element in the (P?1)th matrix with the Pth shift factor to obtain the Pth matrix whose cycle length property is better than a cycle length property of the (P?1)th matrix.

Abstract: This application discloses an information processing method. A communication device obtains an input sequence. The input sequence has a quantity B of information bits. The communication devices transforms the input sequence into one or more code blocks. The communication device encodes each of the code blocks individually, to obtain one or more encoded code blocks. Each of the code blocks has a code block length less than or equal to a maximum code block length. Each of the code blocks includes a segment of the input sequence and may include one or more cyclic redundancy check (CRC) bits corresponding to the segment of the input sequence. The encoded code blocks can meet various channel coding requirements.

Abstract: This application relates to communicating information between communication devices. A channel coding method is disclosed. A communication device obtains an input sequence of K bits. The communication device encodes the input sequence using a low density parity check (LDPC) matrix H, to obtain an encoded sequence. The LDPC matrix H is determined according to a base matrix and a lifting factor Z. The base matrix includes m rows and n columns, m is greater than or equal to 5, and n is greater than or equal to 27. The lifting factor Z satisfies a relationship of 22*Z?K. According to the encoding method provided in the embodiments, information bit sequences of a plurality of lengths can be encoded for transmission between the communication devices.