An apparatus and method for efficiently decoding a low-density parity-check (LDPC) code in a communication or broadcasting system are provided. The disclosure relates to performing decoding of an LDPC code by using layered scheduling or a method equivalent thereto, and provides an LDPC decoding apparatus and method for improving decoding performance without increasing decoding complexity by applying appropriate decoding scheduling according to structural or algebraic characteristics of an LDPC code.

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 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.

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 disclosure provides methods, devices and systems for encoding data in wireless communications. Some implementations more specifically relate to performing a first encoding operation on data bits of a code block to shape the amplitudes of the resultant symbols such that the amplitudes have a non-uniform distribution. In some aspects, the probabilities associated with the respective amplitudes generally increase with decreasing amplitude. For example, the non-uniform distribution of the amplitudes of the symbols may be approximately Gaussian. In some aspects, the first encoding operation is or includes a prefix encoding operation having an effective coding rate greater than 0.94 but less than 1. The first encoding operation is followed by a second encoding operation that also adds redundancy but does not alter the data bits themselves. In some aspects, the second encoding operation is or includes a low-density parity-check (LDPC) encoding operation associated with a coding rate greater than 5/6.

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.

Certain aspects of the present disclosure generally relate to techniques for compactly describing lifted low-density parity-check (LDPC) codes. A method by a transmitting device generally includes selecting a first lifting size value and a first set of lifting values; generating a first lifted LDPC code by applying the first set of lifting values to interconnect edges in copies of a parity check matrix (PCM) having a first number of variable nodes and a second number of check nodes; determining a second set of lifting values for generating a second lifted LDPC code for a second lifting size value based on the first lifted PCM and the first set of lifting values; encoding a set of information bits based the first lifted LDPC code or the second lifted LDPC code to produce a code word; and transmitting the code word.

The present disclosure relates to a pre-5th-Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4th-Generation (4G) communication system such as Long Term Evolution (LTE). A channel encoding method in a communication or broadcasting system includes identifying an input bit size, determining a block size (Z), determining an LDPC sequence for LDPC encoding, and performing the LDPC encoding based on the LDPC sequence and the block size.

A method may comprise receiving a first signal comprising first LDPC bits including systematic bits and parity bits and transmitting information indicating that the first signal was incorrectly received. A second signal comprising second LDPC bits may be received in response to the transmitting. The second signal may include LDPC bits according to a lifting size of an LDPC base graph.

This disclosure provides systems, methods, and apparatus, including computer programs encoded on computer-readable media, for implementing a retransmission protocol in a wireless local area network (WLAN). The retransmission protocol enables a sending station (STA) to communicate additional parity bits associated with an original transmission that included forward error correction (FEC) encoded codewords. Several techniques are described for a receiving STA to indicate which portions of the original transmission was not properly received. The receiving STA may store the original transmission for use with additional parity bits in a subsequent transmission. The sending STA may communicate the additional parity bits in a subsequent transmission to assist the receiving STA recover the data from the original transmission.