Certain aspects of the present disclosure generally relate to techniques for enhanced puncturing and low-density parity-check (LDPC) code structure. A method for wireless communications by a transmitting device is provided. The method generally includes encoding a set of information bits based on a LDPC code to produce a code word, the LDPC code defined by a base matrix having a first number of variable nodes and a second number of check nodes; puncturing the code word according to a puncturing pattern designed to puncture bits corresponding to at least two of the variable nodes to produce a punctured code word; adding at least one additional parity bit for the at least two punctured variable nodes; and transmitting the punctured code word.

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 64800 and a code rate of 7/15. 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).

Certain aspects of the present disclosure provide an efficiently decodable QC-LDPC code which is based on a base matrix, the base matrix being formed by columns and rows, the columns being dividable into one or more columns corresponding to punctured variable nodes and columns corresponding to non-punctured variable nodes. Apparatus at a transmitting side includes a encoder configured to encode a sequence of information bits based on the base matrix. Apparatus at a receiving side configured to receive a codeword in accordance with a radio technology across a wireless channel. The apparatus at the receiving side includes a decoder configured to decode the codeword based on the base matrix.

Certain aspects of the present disclosure generally relate to techniques for puncturing of structured low-density parity-check (LDPC) codes. Certain aspects of the present disclosure generally relate to methods and apparatus for a high-performance, flexible, and compact LDPC code. Certain aspects can enable LDPC code designs to support large ranges of rates, blocklengths, and granularity, while being capable of fine incremental redundancy hybrid automatic repeat request (IR-HARQ) extension while maintaining good floor performance, a high-level of parallelism to deliver high throughout performance, and a low description complexity.

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.

Systems and methods are disclosed for processing data. In one exemplary implementation, there is provided a method of generating H output data from W data input streams produced from input data. Moreover, the method may include generating the H discrete output data components via application of the W data inputs to one or more transforming components or processes having specified mathematic operations and/or a generator matrix functionality, wherein the W data inputs are recoverable via a recovery process capable of reproducing the W data inputs from a subset (any W members) of the H output data streams. Further exemplary implementations may comprise a transformation process that includes producing an H-sized intermediary for each of the W inputs, combining the H-sized intermediaries into an H-sized result, and processing the H-sized result into the H output data structures, groups or streams.

A method of transmitting a message includes, for each data block, generating a root matrix using a generator, generating a quasi-cyclic matrix H using the root matrix, encoding the block using H to create a codeword, and transmitting the codeword. The root matrix includes three submatrices: an identity matrix in an upper-left-hand portion of the root matrix, an identity matrix in a lower-left-hand portion of the root matrix, and a circulant matrix in a right-hand portion of the root matrix. The circulant matrix equals the sum of an identity matrix and an identity matrix with rows shifted once to the right. Generating H includes expanding the root matrix by replacing 0 elements in the root matrix by a square matrix of 0 elements and replacing 1 elements in the root matrix by a shifted diagonal matrix. Non-zero elements of the diagonal matrix are selected from GF(q) based on the generator.

An encoding and decoding method of low-density parity-check code is disclosed. The method is following steps: a high rate check code is transferred to a check matrix having a protograph. The check matrix is extended to form an extended base matrix and is split to form a split base matrix. The extended base matrix and the split base matrix are respectively calculated to generate their decoding threshold by a protograph extrinsic information transfer chart. The base matrix with the lower decoding threshold is considered as a low rate base matrix. Repeating the above process until a stop condition is satisfied. The last low rate base matrix is expanded to form a parity check matrix. The transmission data is encoded and decoded by the parity check matrix.

In one embodiment, a method includes reading a codeword stored to a memory, computing a syndrome word based on a product of the codeword and a parity check matrix derived from a linear block code, setting a flag to a first value indicating that the codeword includes no errors in response to a first determination requiring that the syndrome word is an all-zero vector, setting the flag to a second value indicating that the codeword includes exactly one single-bit error in response to a second determination requiring that the syndrome word equals a column of the parity check matrix, setting the flag to a third value indicating that the codeword includes an odd number of multiple bit errors in response to a third determination, and setting the flag to a fourth value indicating that the codeword includes an even number of multiple bit errors in response to a fourth determination.

In a transmitting device, in interchanging to interchange a code bit of an LDPC code in which a code length is 16200 bits and an encoding rate is 7/15 with a symbol bit of a symbol corresponding to any of 8 signal points defined by 8PSK, when 3 bits of code bits stored in three units of storages having a storage capacity of 16200/3 bits and read bit by bit from the units of storages are allocated to one symbol, a bit b0, a bit b1, and a bit b2 are interchanged with a bit y1, a bit y0, and a bit y2, respectively. A position of the interchanged code bit obtained from data transmitted from the transmitting device is returned to an original position. The present technology is applicable to a case of transmitting data using an LDPC code, for example.