A quasi-cyclic LDPC coding and decoding method and apparatus, and an LDPC coder and decoder. The method includes: determining from a mother basis matrix set a basis matrix used for low density parity check (LDPC) coding (S202), wherein the basis matrix used for LDPC coding includes a first-type element and a second-type element, the first-type element corresponds to an all-zero square matrix, the second-type element corresponds to a matrix obtained by means of a cyclic shift of a unit matrix according to a value of the second-type element, and dimensions of the all-zero square matrix and the unit matrix are equal; and performing LDPC coding on an information sequence to be coded according to the basis matrix used for LDPC coding, and/or performing LDPC decoding on a data sequence to be decoded according to the basis matrix used for LDPC coding (S204).

The present technology relates to a transmission device, a transmission method, a reception device, and a reception method for securing good communication quality in data transmission using an LDPC code. LDPC coding for information bits with an information length K=N×r is performed on the basis of an extended parity check matrix having rows and columns extended by a predetermined puncture length L with respect to a parity check matrix of an LDPC code with a code length N of 69120 bits and a coding rate r of 14/16, so that an extended LDPC code having parity bits with a parity length M=N+L−K is generated. A head of the information bits of the extended LDPC code is punctured by L, so that a punctured LDPC code with the code length N of 69120 bits and the coding rate r is generated. The extended parity check matrix includes an A matrix of M1 rows and K columns expressed by a predetermined value M1 and the information length K=N×r, a B matrix of M1 rows and M1 columns, a Z matrix of M1 rows and N+L−K−M1 columns, a C matrix of N+L−K−M1 rows and K+M1 columns, and a D matrix of N+L−K−M1 rows and N+L−K−M1 columns. The present technology can be applied to data transmission and the like using an LDPC code.

The present technology relates to a transmission method and a reception device capable of ensuring good communication quality in data transmission by using an LDPC code. In group-wise interleaving, an LDPC code with a code length N of 69120 bits is interleaved in units of bit groups of 360 bits. In group-wise deinterleaving, an arrangement of the LDPC code after the group-wise interleaving is returned to an original arrangement. The present technology can be applied, for example, to the case of performing data transmission by using an LDPC code or the like.

The present technology relates to a data processing apparatus and a data processing method that are able to provide an LDPC code with a good error rate. An LDPC encoder performs coding by an LDPC code having a code length of 16200 bits and a code rate of 12/15. The LDPC code includes an information bit and a parity bit, and a parity check matrix H is configured with an information matrix portion corresponding to the information bit of the LDPC code and a parity matrix portion corresponding to the parity bit. An information matrix portion of the parity check matrix H is represented by a parity check matrix initial value table representing a position of an element of 1 in the information matrix portion at an interval of 360 columns. The present technology may be applied to a case of performing an LDPC coding and an LDPC decoding.

A transmitting apparatus and a receiving apparatus are provided. The transmitting apparatus includes: an encoder configured to generate a low density parity check (LDPC) codeword by performing LDPC encoding; an interleaver configured to interleave the LDPC codeword; and a modulator configured to modulate the interleaved LDPC codeword according to a modulation method to generate a modulation symbol. The interleaver is formed of a plurality of columns including a plurality of rows, respectively, and comprises: a block interleaver configured to divide each of the plurality of columns into a first part and a second part, and interleave a plurality of bit groups constituting the LDPC codeword, all bit groups interleaved by the first part are interleaved as bits included in a same bit group are written in a same column of the first part, at least one bit group interleaved by the second part is interleaved as bits included in the at least one bit group are divided and written in at least two columns constituting the second part.

The present technology relates to a data processing device and a data processing method, which are capable of securing excellent communication quality in data transmission using an LDPC code. In group-wise interleave, an LDPC code in which a code length N is 16200 bits and an encoding rate r is 12/15, 6/15, or 8/15 is interleaved in units of bit groups of 360 bits. In group-wise deinterleave, a sequence of the LDPC code that has undergone the group-wise interleave is restored to an original sequence. For example, the present technology can be applied to a technique of performing data transmission using an LDPC code.

Provided is a system and method for determining a generalized Low-Density Parity-Check (LDPC) code for forward error correction channel coding that has a repeat-accumulate code structure.

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.

The present technology relates to a transmission method and a reception device capable of ensuring good communication quality in data transmission by using an LDPC code. In group-wise interleaving, an LDPC code with a code length N of 69120 bits is interleaved in units of bit groups of 360 bits. In group-wise deinterleaving, an arrangement of the LDPC code after the group-wise interleaving is returned to an original arrangement. The present technology can be applied, for example, to the case of performing data transmission by using an LDPC code or the like.

A system for generating a parity check matrix for low-density parity-check (LDPC) codes includes a memory and a processing circuitry that retrieves a base matrix from the memory. The base matrix represents sets of valid and invalid positions for a set of circulant matrices. The processing circuitry determines a value for each valid position based on a heuristic function. The value for each valid position indicates a corresponding circulant matrix of the set of circulant matrices. The processing circuitry replaces each valid position with the corresponding circulant matrix based on the determined value, and each invalid position with a null matrix, to generate the parity check matrix. The parity check matrix thus generated has a high girth and equal distribution of cycles within the parity check matrix.