A method for decoding a codeword transmitted over a channel demodulates data received over the channel to produce an initial estimate of belief messages for bits of the codeword and decodes the codeword using a belief propagation (BP) decoding that iteratively passes the belief messages between a set of variable nodes representing the bits of the codeword and a set of check nodes representing parity-check constraints on the bits of the codeword until a termination condition is met. The BP decoding selects a look-up table based on a probability of the belief messages and maps, using the look-up table, values of at least two incoming belief messages to values of at least one outgoing belief message that forms an incoming belief message in a subsequent iteration of the BP decoding.

An apparatus for processing data includes a storage medium operable to store encoded data, and a read channel circuit with a low density parity check encoder operable to encode data to generate the encoded data, and a low density parity check decoder operable to decode the encoded data retrieved from the storage medium. The read channel circuit is operable to perform a column rotation on the encoded data prior to storage and after retrieval before decoding.

Disclosed is a multi-element code modulation mapping method and device, relating to communications and designed to improve communication reliability. The method includes that: multi-element domain coding is performed on a first sequence including K multi-element codes to obtain a second sequence including N multi-element codes; K.sub.1 and K.sub.2 are calculated according to a multi-element domain element number q and a modulation order M, wherein K.sub.1*log.sub.2 q=K.sub.2*log.sub.2 M, both K.sub.1 and K.sub.2 are integers not smaller than 2, and both q and M are power of 2; the second sequence is divided into z groups of multi-element codes with each group including K.sub.1 multi-element codes, wherein C=formula (I), and formula (II) represents rounding up; each group of multi-element codes is mapped to a constellation diagram to form K.sub.2 Mth-order modulation symbols; and z groups of Mth-order modulation symbols are sequentially cascaded to form a modulation symbol to be sent. The present disclosure further discloses a computer storage medium.

A communication device (alternatively, device) includes a processor configured to support communications with other communication device(s) and to generate and process signals for such communications. In some examples, the device includes a communication interface and a processor, among other possible circuitries, components, elements, etc. to support communications with other communication device(s) and to generate and process signals for such communications. The device receives a non-binary low density parity check (NB-LDPC) coded signal. The device then decodes the NB-LDPC coded signal using a NB-LDPC matrix to generate estimates of information bits encoded therein. The NB-LDPC matrix is characterized by a base proto-matrix having elements that represent sub-matrices, and the elements are selected from a finite Galois field that includes symbols. In another example, the device encodes other information bits using a generator matrix to generate another NB-LDPC coded signal and then transmits this other NB-LDPC coded signal.

The present technology relates to a data processing device and a data processing method which can ensure high communication quality in data transmission using LDPC codes.

In group-wise interleaving, an LDPC code having a code length N of 64800 bits and a coding rate r of 13/15 is interleaved in a unit of a bit group of 360 bits. In group-wise deinterleaving, a sequence of bit groups of the LDPC code which has been subjected to the group-wise interleaving is returned to an original sequence. The present technology can be applied to, for example, a case in which data transmission is performed using LDPC codes.

Various embodiments of the present disclosure adjusts the size (nm) of a message input to a corresponding check node in case the unsatisfied check equation increases as the iteration count increases. Another embodiment of the present disclosure relates to a method for selecting a message and grasps the data distribution characteristics of the message vector values converted using the signal to noise ratio (SNR) and modulation and coding scheme (MCS) parameters of the receiver to select the message value with a value smaller than the threshold value in each message vector.

An apparatus for decoding data includes a data decoding circuit configured to decode data encoded with an irregular low density parity check code based on a parity check matrix with non-uniform column weights, and at least one scaling circuit configured to scale values in the data decoding circuit with a scaling value that is dependent at least in part on a column weight of the likelihood values being scaled.

A method for decoding a codeword transmitted over a channel demodulates data received over the channel to produce an initial estimate of belief messages for bits of the codeword and decodes the codeword using a belief propagation (BP) decoding that iteratively passes the belief messages between a set of variable nodes representing the bits of the codeword and a set of check nodes representing parity-check constraints on the bits of the codeword until a termination condition is met. The BP decoding selects a look-up table based on a probability of the belief messages and maps, using the look-up table, values of at least two incoming belief messages to values of at least one outgoing belief message that forms an incoming belief message in a subsequent iteration of the BP decoding.

An apparatus for processing data includes a storage medium operable to store encoded data, and a read channel circuit with a low density parity check encoder operable to encode data to generate the encoded data, and a low density parity check decoder operable to decode the encoded data retrieved from the storage medium. The read channel circuit is operable to perform a column rotation on the encoded data prior to storage and after retrieval before decoding.

A decoder includes a processor and a scheduler coupled to the processor. The processor is configured to process a set of nodes related to a representation of a codeword during a first decode iteration. The nodes are processed in a first order. The scheduler is configured to generate a schedule that indicates a second order of the set of nodes. The second order is different from the first order.