A packet processing method includes generating, by a processor of a network device, a first encoding task based on M original packets in a to-be-processed first data stream, where M is a positive integer, and where the first encoding task instructs to encode the M original packets; and performing, by a target hardware engine of the network device and based on the first encoding task, forward error correction (FEC) encoding on the M original packets to obtain R redundant packets, where R is a positive integer.

A packet processing method includes generating, by a processor of a network device, a first encoding task based on M original packets in a to-be-processed first data stream, where M is a positive integer, and where the first encoding task instructs to encode the M original packets; and performing, by a target hardware engine of the network device and based on the first encoding task, forward error correction (FEC) encoding on the M original packets to obtain R redundant packets, where R is a positive integer.

Methods and apparatuses for generating optimized LDPC codes are proposed. One of the methods is a method for generating an optimized LDPC code for an asymmetric transmis¬ sion channel. The method includes receiving an initial LDPC code for the asymmetric transmission channel. Further, the method includes performing a density evolution threshold optimization for the initial LDPC code in order to obtain the optimized LDPC code for the asymmetric transmission channel. A uniformly mixed symmetric channel density for the asymmetric transmission channel is used in the density evolution threshold optimization.

A bit interleaver, a bit-interleaved coded modulation (BICM) device and a bit interleaving method are disclosed herein. The bit interleaver includes a first memory, a processor, and a second memory. The first memory stores a low-density parity check (LDPC) codeword having a length of 64800 and a code rate of 3/15. The processor generates an interleaved codeword by interleaving the LDPC codeword on a bit group basis. The size of the bit group corresponds to a parallel factor of the LDPC codeword. The second memory provides the interleaved codeword to a modulator for 16-symbol mapping.

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).

Systems and methods in accordance with various embodiments of the invention perform lossless source coding. Nested code structures are utilized to perform Random Access Source Coding (RASC), where the number of active encoders is initially unknown. Decoders can attempt to source decode using a number of Slepian-Wolf decoders corresponding to an estimated number of sources. Multiple source encoders are configured to receive start messages and transmit portions of codewords, selected by source encoding data from sources to remove redundancy, until an end of epoch message is received.

Systems and methods in accordance with various embodiments of the invention perform lossless source coding. Nested code structures are utilized to perform Random Access Source Coding (RASC), where the number of active encoders is initially unknown. Decoders can attempt to source decode using a number of Slepian-Wolf decoders corresponding to an estimated number of sources. Multiple source encoders are configured to receive start messages and transmit portions of codewords, selected by source encoding data from sources to remove redundancy, until an end of epoch message is received.

An LDPC parity check matrix includes a systematic portion having a plurality of systematic elements and a parity portion having a plurality of parity elements. The value of each systematic element determines a cyclic shift to be applied to rows of an identity submatrix corresponding to that element. The value of each parity element determines a cyclic shift to be applied to rows of an identity submatrix corresponding to that element. The weights of two or more columns of the parity portion are the same.

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-HARD) extension while maintaining good floor performance, a high-level of parallelism to deliver high throughout performance, and a low description complexity.

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 16200 and a code rate of 3/15. 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).