The disclosure relates to a communication technique for converging a 5G communication system for supporting a higher data transfer rate beyond a 4G system with an IoT technology, and a system therefor. The disclosure may be applied to intelligent services (for example, smart home, smart buildings, smart cities, smart cars or connected cars, health care, digital educations, retail business, security and safety-related services, etc.) based on a 5G communication technology and an IoT-related technology. The disclosure provides an apparatus and a method for efficiently decoding a low-density parity-check (LDPC) code in a communication or broadcasting system. Further, the disclosure provides an LDPC decoding device and method for improving decoding performance without increasing the decoding complexity by applying suitable decoding scheduling according to the structural or algebraic characteristics of the LDPC code in a process of decoding the LDPC code using layered scheduling or a scheme similar thereto. Further, a method of a low density parity check (LDPC) decoding performed by a receiving device in a wireless communication system is provided, the method comprising: receiving, from a transmitting device, a signal corresponding to input bits; performing demodulation based on the signal to determine values corresponding to the input bits; identifying a number of the input bits based on the signal; identifying a base matrix and a lifting size based on the number of the input bits; identifying a parity check matrix based on the base matrix; identifying an index corresponding to the values; determining a number of layers based on the index and the lifting size; determining an order for LDPC decoding based on the number of layers and a predetermined sequence; and performing LDPC decoding to determine the input bits based on the values, the parity check matrix and the order.

An improved layered decoding method for a low density parity check (LDPC) code and a device therefor are disclosed. Disclosed is the layered decoding method for an LDPC code, capable of determining whether decoding is successful by performing a syndrome check on each check node at every variable node update. In addition, the syndrome check can be performed by using reduced variable nodes, thereby reducing decoding power consumption and decoding time consumption.

Provided is an encoding method and device and a decoding method and device for structured LDPC. The encoding method includes: determining a base matrix used for encoding and performing an LDPC encoding operation on a source information bit sequence according to the base matrix and an expansion factor Z corresponding to the base matrix to obtain a codeword sequence, where Z is a positive integer. The base matrix includes multiple submatrices and the submatrices include an upper-left submatrix Hb1 and an upper-left submatrix Hb2, and the upper-left submatrix Hb1 is an upper-left submatrix of the upper-left submatrix Hb2.

The present invention related to a 5G or pre-5G communication system to be provided to support a higher data transmission rate since 4G communication systems like LTE. The present invention relates to a method and an apparatus for encoding a channel in a communication or broadcasting system supporting parity-check matrices having various sizes are provided. The method for encoding a channel includes determining a block size of the parity-check matrix; reading a sequence for generating the parity-check matrix, and transforming the sequence by applying a previously defined operation to the sequence based on the determined block size.

A method for encoding a quasi-cyclic low-density parity-check (LDPC) code according to an embodiment of the present invention may comprise the steps of: generating a multi-edge LDPC code matrix including a high rate code matrix and a single parity check code matrix; and encoding a signal by using the multi-edge LDPC code matrix, wherein the single parity check code matrix includes a first matrix having a non-row-orthogonal structure matrix and a second matrix having a pure row-orthogonal structure, which are concatenated.

The disclosure relates to a communication scheme and system for converging a 5th-Generation (5G) communication system for supporting higher data rates beyond a 4th-Generation (4G) system with technology for the Internet of Things (IoT). The disclosure may be applied to intelligent services based on 5G communication technology and IoT-related technology (for example, smart homes, smart buildings, smart cities, smart cars or connected cars, health care, digital education, smart retail, and security- and safety-related services). The method and apparatus for data repetition transmission for cooperative network communication. A method includes determining a transport block; generating coded bits for the transport block based on a first low density parity check code; applying rate matching to the coded bits based on a first redundancy version pattern; generating a first modulation symbol by performing modulation on the coded bits to which rate matching is applied; and transmitting, to a terminal the first modulated symbol.

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 disclosure provides decoding of a low-density parity-check (LDPC) code in a wireless communication system, and a decoding method of the LDPC code may include receiving a codeword, performing decoding iterations on the codeword a predefined maximum number of times using a parity check matrix, performing partial decoding using a partial area of the parity check matrix, and determining decoding success or failure of the codeword based a result of the partial decoding.

A quasi-cyclic low density parity check (QC LDPC) code rate matching method is disclosed. According to the rate matching method in the present disclosure, the minimum lifting value can be selected from among lifting values by which a codeword longer than a target code block can be generated. A coding gain through retransmission can be acquired by generating the codeword that is longer than the target code block. In addition, by selecting a lifting value of a proper magnitude, rate matching for information bit sequences of various lengths can be performed.

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 method for constructing a low-density parity-check (LDPC) code using a structured base parity check matrix with permutation matrix, pseudo-permutation matrix, or zero matrix as constituent sub-matrices; and expanding the structured base parity check matrix into an expanded parity check matrix. A method for constructing a LDPC code using a structured base parity check matrix H=[H.sub.d|H.sub.p], H.sub.d is the data portion, and H.sub.p is the parity portion of the parity check matrix; the parity portion of the structured base parity check matrix is such so that when expanded, an inverse of the parity portion of the expanded parity check matrix is sparse; and expanding the structured base parity check matrix into an expanded parity check matrix. A method for encoding variable sized data by using the expanded LDPC code; and applying shortening, puncturing.