A low density parity check (LDPC) decoder initializing variable nodes with a value of a codeword and outputting the updated variable nodes as decoded messages with reference to an irregular parity check matrix. The LDPC decoder includes a plurality of unit logic circuits operating in a single mode in which all the unit logic circuits update one variable node group including at least one variable node, or a multi-mode in which each of the unit logic circuits updates a plurality of variable node groups in parallel by updating different variable nodes, and a mode controller controlling the plurality of unit logic circuits to update a high-degree variable node group having a degree greater than a threshold degree among the variable node groups in the single mode, and update a low-degree variable node group having a degree less than or equal to the threshold degree among the variable node groups in the multi-mode.

A circuit with an interface, a transmit data register coupled to the interface, a storage device coupled to the transmit data register and including a plurality of storage locations, each storage location adapted to store a data unit, and a serial register coupled between the storage device and an output. The circuit also includes a CRC generation circuit having an input coupled between an output of the transmit data register and the storage device. The CRC generation circuit includes a first CRC generation block for providing a CRC in response to an X-bit data unit and an X-bit polynomial and a second CRC generation block with a collective X-bit input for providing a CRC in response to an X-bit data unit and a 2X-bit polynomial in a single clock cycle and a 2X-bit data unit and a 2X-bit polynomial in two clock cycles.

A bit interleaving method involves applying a bit permutation process to a QC-LDPC codeword made up of N cyclic blocks each including Q bits, and dividing the codeword after the permutation process into a plurality of constellation words each including M bits, the codeword being divided into FN/M folding sections, each of the constellation words being associated with one of the FN/M folding sections, and the bit permutation process being applied such that each of the constellation words includes F bits from each of M/F different cyclic blocks in a given folding section associated with a given constellation word.

Uncorrectable memory errors may be reduced by determining a logical array address for a set of memory arrays and transforming the logical array address to at least two unique array addresses based, at least in part, on logical locations of at least two memory arrays within the set of memory arrays. The at least two memory arrays are then accessed using the at least two unique array addresses, respectively.

A deinterleaver device, a method for deinterleaving, an interleaver device, and a method for interleaving are provided. The method for deinterleaving includes: providing a memory and a stream count for a frame; virtually dividing the memory into equal sections, wherein a section count equals the stream count; calculating a write address for a sample of the samples based on a location of the sample in the frame and a correspondence of the location to one of the sections; receiving the sample; and writing the received sample to the write address, wherein the calculating and the write address corresponds to a correct deinterleaving location in one of the sections for the sample.

A processor of an apparatus establishes a wireless communication link with at least one other apparatus via a transceiver of the apparatus. The processor wirelessly communicates with the other apparatus via the wireless communication link by: selecting a first shift-coefficient table from a plurality of shift-coefficient tables; generating a QC-LDPC code using a base matrix and at least a portion of the first shift-coefficient table; selecting a codebook from a plurality of codebooks embedded in the QC-LDPC code; storing the selected codebook in a memory associated with the processor; encoding data using the selected codebook to generate a plurality of modulation symbols of the data; and controlling the transceiver to multiplex, convert, filter, amplify and radiate the modulation symbols as electromagnetic waves through one or more antennas of the apparatus to transmit the modulation symbols of the data to the other apparatus via the wireless communication link.

A bit interleaving method involves applying a bit permutation process to a QC-LDPC codeword made up of N cyclic blocks each including Q bits, and dividing the codeword after the permutation process into a plurality of constellation words each including M bits, the codeword being divided into FN/M folding sections, each of the constellation words being associated with one of the FN/M folding sections, and the bit permutation process being applied such that each of the constellation words includes F bits from each of M/F different cyclic blocks in a given folding section associated with a given constellation word.

A method for communication device processing a data block in a low-density parity-check (LDPC) encoder includes the steps of, if a size of a payload is equal to or greater than a prescribed size, performing code block segmentation, and performing encoding in a unit of a code block on code blocks according to the code block segmentation. In this case, the code block segmentation may be performed by a payload size supported by a parity check matrix (H) corresponding to a coding rate of the LDPC encoder.

A user station for a serial bus system. The user station includes a communication control device for controlling a communication of the user station with at least one other user station, and a transceiver device to serially transmit a transmission signal, generated by the communication control device, onto a bus, and serially receive signals from the bus. The communication control device generates the transmission signal according to a frame and inserts into the frame two check sums that include different bits of the frame in the computation. The communication control device inserts dynamic stuff bits into the frame in such a way that an inverse stuff bit is inserted into the bit stream of the frame after 5 identical bits in succession. The communication control device computes the two check sums so that a maximum of one of the two check sums includes the dynamic stuff bits in the computation.

An error correction encoder (10) includes an interleaver circuit (31), encoding circuits (32.sub.1, 32.sub.2) and a deinterleaver circuit (33). The interleaver circuit (31) generates, in a standard speed mode, a single series of yet-to-be-coded bit sequences (IL.sub.1) on the basis of the bits in plural columns that are arranged at an interval of C columns in a single series of transmission frames, and generates, in a two-times speed mode, two series of yet-to-be-coded bit sequences (IL.sub.1, IL.sub.2) on the basis of the bits in plural columns that are arranged at an interval of C/2 columns in each of two series of transmission frames. The encoding circuits (32.sub.1, 32.sub.2) apply error-correction coding to either the single series of yet-to-be-coded bit sequences (IL.sub.1) or the two series of yet-to-be-coded bit sequences (IL.sub.1, IL.sub.2).