A transmitter is provided. The transmitter includes: a low density parity check (LDPC) encoder configured to encode input bits to generate an LDPC codeword including the input bits and parity bits; a repeater configured to select at least a part of bits constituting the LDPC codeword and add the selected bits after the input bits; and a puncturer configured to puncture at least a part of the parity bits.

An apparatus (100) for providing an joint error correction code (140) for a combined data frame (254) comprising first data (112) of a first data channel and second data (122) of a second data channel comprises a first error code generator (110) configured to provide, based on a linear code, information on a first error correction code (114a, 114b) using the first data (112). The apparatus further comprises a second error code generator (120) configured to provide, based on the linear code, information on a second error correction code (124) using the second data (122). The apparatus is configured to provide the joint error correction code (140) using the information on the first error correction code (114a, 114b) and the information on the second error correction code (124).

The present invention discloses an erasure code calculation method, including the following steps: S1) splitting original data, and building an original encoding matrix M; S2) acquiring a transverse exclusive OR encoding matrix M1; S3) acquiring a longitudinal exclusive OR encoding matrix M2; S4) acquiring an exclusive OR encoding matrix M3 according to the transverse exclusive OR encoding matrix M1 and the longitudinal exclusive OR encoding matrix M2; S5) transforming a data position of the transverse exclusive OR encoding matrix M1 to acquire a storage matrix M4; S6) judging whether storage nodes at which the last column of data of the storage matrix M4 is stored are damaged; S7) restoring the lost data according to a position 1 of the damaged node; and S8) restoring the lost data according to a position 2 of the damaged node. In the present invention, the operation is rapid, and calculation efficiency is high.

A new unequal-error-protection method that is based on using a particular parity-check-matrix structure for LDPC codes.

The data decoding apparatus includes a communication unit receiving a bit signal with encoded data; a first operation unit performing a bit shift on the bit signal by a first length corresponding to a length of a spreading code used to encode the data to generate a first operation stream; a second operation unit generating a second operation stream from which the spreading code is removed using the bit signal and the first operation stream; a third operation unit performing a bit shift on the second operation stream by a second length to generate a third operation stream; a fourth operation unit generating a fourth operation stream from which the data is removed using the second operation stream and the third operation stream; and a polynomial generator generating a generator polynomial capable of decoding the data encoded using the fourth operation stream.

An encoding method includes: receiving, by an encoder, an information for encoding; generating, by the encoder, a first portion codeword according to a first encoding rule and the information for encoding, wherein the first encoding rule is an encoding rule configured to generate LDPC code; generating, by the encoder, a second portion codeword according to a second encoding rule different from the first encoding rule and a double check region of the first portion codeword; and concatenating, by the encoder, the first portion codeword and the second portion codeword to generate a codeword. A plurality of trapping sets corresponding to the first encoding rule include at least one error bit within the double check region.

A data storage device has a controller that is configured to generate SECDED codes based on a plurality (at least 2) of codes, where each of the constituent codes is a cyclic code over a finite field of size 2.sup.m for some integer m. Any 2 constituent codes are associated with 2.sup.m1 and 2.sup.m2, where m1 and m2 are coprime (i.e., gcd(m1,m2)=1) where gcd is the greatest common divisor. In such a case, it is possible to generate a cyclic code of length (2.sup.m1−1)*(2.sup.m2−1), which will be a long code, but enjoy the complexity, in encoding and decoding, of the small fields of the constituent codes.

A transmitter is provided. The transmitter includes: a low density parity check (LDPC) encoder configured to encode input bits to generate an LDPC codeword including the input bits and parity bits; a repeater configured to select at least a part of bits constituting the LDPC codeword and add the selected bits after the input bits; and a puncturer configured to puncture at least a part of the parity bits.

Methods of transmitting blocks of incremental redundant coded bits are provided. Methods include concatenating, using an outer encoder, bits of an input bit vector to an outer encoded bit vector that has fewer bits than the input bit vector, wherein the outer encoded bit vector includes a mixture of information bits from the input bit vector. Methods include encoding the outer encoded bit vector into inner encoded data that is mapped to multiple data transmission channels that each include a channel reliability value. A first portion of the data transmission channels is used to transmit information bits corresponding to the outer encoded bit vector and a second portion of the data transmission channels is used to transmit frozen bits that include no information.

A data transmitting method using an LDPC code as an error correction code is provided. The method includes providing a parity check matrix of LDPC code, wherein the size of the parity check matrix is (m1+m2)×(n1+n2); in a sending side, encoding an input data of K bits with a encoder to generate a first block code of (n1+n2) bits, according to the parity check matrix; through a transmitting channel, sending n1 bits of the first block code from the sending side to a receiving side, wherein n2 bits of the first block code are not transmitted; and receiving the n1 bits of the first block code in the receiving side, and using the parity check matrix to perform a decoding algorithm to the received first block code to iterative decodes a second block code of (n1+n2) bits with a decoder. Furthermore, a data decoding method thereof is also provided.