A transmitting device is described for a communication system. The transmitting device obtains an information message comprising information bits addressed for a receiving device and encodes the information message to obtain a codeword. The transmitting device rate-matches the codeword to produce a rate-matched codeword comprising systematic bits and parity-check bits. Furthermore, the transmitting device jointly interleaves the systematic bits and parity-check bits of the rate-matched codeword to obtain an interleaved codeword. The systematic bits of the interleaved codeword are mapped to modulation label positions of a modulation constellation with first reliabilities, and the parity-check bits of the interleaved codeword are mapped to modulation label positions of the modulation constellation with second reliabilities.

A method for transmitting an information block on the basis of a low density parity check (LDPC) code in a wireless communication system, according to the present disclosure, may comprise: encoding an information block on the basis of a LDPC basegraph H_BG including [MATRIX]; and transmitting the encoded information block. Each element of H_BG is either zero (“0”) or one (“1”), and each element which is “0”, among the elements of H_BG, may represent a Z×Z zero matrix, and each element which is “1”, among the elements of H_BG, may represent a Z×Z matrix acquired on the basis of a circular permutation matrix acquired by circularly shifting a Z×Z identity matrix to the left or right. The submatrix T_BG of H_BG may be a dual diagonal matrix, and the submatrix D_BG of H_BG may be a dual diagonal matrix. The encoding of the information block on the basis of H_BG may comprise encoding the information block on the basis of a parity check matrix (PCM) H which corresponds to H_BG.

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.

Disclosed herein is a decoder 10 for decoding a family of L rate compatible parity check codes, said family of parity check codes comprising a first code that can be represented by a bipartite graph having variable nodes, check nodes, and edges, and L−1 codes of increasingly lower code rate, among which the i-th code can be represented by a bipartite graph corresponding to the bipartite graph representing the (i−1)-th code, to which an equal number of n.sub.i variable nodes and check nodes are added, wherein the added check nodes are connected via edges with selected ones of the variable nodes included in said i-th code, while the added variable nodes are connected via edges with selected added check nodes only. The decoder comprising L check node processing units 14, among which the i-th check node processing unit processes only the check nodes added in the i-th code over the (i−1)-th code, wherein said L check node processing units 14 are configured to operate in parallel.

A method of producing a set of coded bits from a set of information bits for transmission between a first node and a second node in a wireless communications system, the method comprises generating a codeword vector by encoding the set of information bits with a low-density parity-check code, wherein the codeword vector is composed of systematic bits and parity bits. The method comprises performing circular buffer-based rate matching on the generated codeword vector to produce the coded bits for transmission, wherein the circular buffer-based rate matching comprises puncturing a first plurality of systematic bits.

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.

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.

Methods, systems, and devices for wireless communication are described that support channel selection for parity bits in polar coding techniques. In some cases, an encoder or decoder of a wireless device may assign information bits, frozen bits, and parity check bits to polar channels of an encoder or decoder based on reliability metrics. The information bits may initially be assigned and based on a channel index of the first information bit, the parity check bits may be assigned to channels having higher channel indices than the first information bit. After assignment, the bits may be encoded or decoded.

A pre-5th-generation (pre-5G) or 5G communication system for supporting higher data rates beyond a 4th-generation (4G) communication system, such as long term evolution (LTE) is provided. A channel encoding method in a communication or broadcasting system includes identifying an input bit size, determining a block size (Z), determining a low density parity check (LDPC) sequence to perform LDPC encoding, and performing the LDPC encoding based on the LDPC sequence and the block size.

A method for encoding a quasi-cyclic low-density parity-check (LDPC) code according to an embodiment of the present invention comprises: a step of generating a multi-edge LDPC code matrix which comprises a high rate code matrix and a single parity check code matrix; and a step of encoding a signal using the multi-edge LDPC code matrix, wherein the single parity check code matrix may be configured by connecting a first matrix which is configured as a quasi row-orthogonal structure matrix and a second matrix which is configured as a pure row-orthogonal structure.