Protograph-based LDPC codes are obtained from z-row-orthogonal base matrices with some additional structure constraints, such as a diagonal and/or double-diagonal structure, in order to allow a high parallelization that is a multiple of z, while having an efficient encoding or decoding. A “big” base matrix is constructed from a structured square submatrix in order to have a WiMAX-like structure and a z-row-orthogonality. Also, starting from a “smaller” base matrix having a part arranged in a double-diagonal shape with tail-biting one, an expansion by a factor equal to z can be performed, followed by an addition of a single one-entry into the last column at a specific location, thereby obtaining a three-degree column, and followed by a row and/or column permutation in order to obtain a base matrix in a WiMAX-like structure.

A channel encoding method in a communication or broadcasting system is provided. The channel encoding method includes reading a first sequence corresponding to a parity check matrix, converting the first sequence to a second sequence by applying a certain rule to a block size corresponding to a parity check matrix and the first sequence, and encoding information bits based on the second sequence. The block size has at least two different integer values.

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 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.

A bit interleaver, a bit-interleaved coded modulation (BICM) device and a bit interleaving method are disclosed herein. The bit interleaver includes a first memory, a processor, and a second memory. The first memory stores a low-density parity check (LDPC) codeword having a length of 16200 and a code rate of 3/15. The processor generates an interleaved codeword by interleaving the LDPC codeword on a bit group basis. The size of the bit group corresponds to a parallel factor of the LDPC codeword. The second memory provides the interleaved codeword to a modulator for 64-symbol mapping.

A transmission apparatus including a FEC encoder configured to obtain payload data structured as information words each having a predetermined first number of information bits and to encode information words having a second number of information bits into FEC code words each having a predetermined code word length.

A method for performing low density parity check (LDPC) coding of a transmitter in a wireless communication system, according to the present disclosure, may comprise the steps of: acquiring a proto-matrix corresponding to a protograph; on the basis of weights and lifting factors of columns of the proto-matrix, acquiring one or more permuted vectors corresponding to each of the columns, a first permuted vector included in the one or more permuted vectors having been randomly generated; distributing the one or more permuted vectors for each row of a corresponding column; on the basis of the distributed one or more permuted vectors, acquiring a plurality of lifted sub matrices corresponding to a plurality of elements of the proto-matrix; generating a base graph on the basis of the plurality of lifted sub matrices; generating a parity check matrix (PCM) on the basis of the base graph; and performing LDPC coding by using the PCM.

A low density parity check (LDPC) encoder, an LDPC decoder, and an LDPC encoding method are disclosed. The LDPC encoder includes first memory, second memory, and a processor. The first memory stores an LDPC codeword having a length of 16200 and a code rate of 3/15. The second memory is initialized to 0. The processor generates the LDPC codeword corresponding to information bits by performing accumulation with respect to the second memory using a sequence corresponding to a parity check matrix (PCM).

The present disclosure relates to a pre-5.sup.th-Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4.sup.th-Generation (4G) communication system such as Long Term Evolution (LTE). The present disclosure discloses a method for effective retransmission when HARQ is applied to data encoded with a low density parity check (LDCP) code. A data transmission method of the transmitter may include: initially transmitting data encoded with an LDPC code to a receiver; receiving a negative acknowledgement (NACK) from the receiver; determining retransmission related information for data retransmission; and retransmitting, in response to the NACK, LDPC-encoded data based on the retransmission related information.

A low density parity check (LDPC) channel encoding method is used in a wireless communications system. A communication device encodes an input bit sequence by using an 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 base matrix may be one of eight exemplary designs. The encoding method can be used in various communications systems including fifth generation (5G) telecommunication systems, and can support various encoding requirements for information bit sequences with different code lengths.

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.