The present invention relates to a layered semi-parallel LDPC decoder system having a single permutation network, and belongs to the field of decoder hardware design. The system comprises a layered decoding architecture of the single permutation network, a layered semi-parallel decoding architecture of the single permutation network, a pipeline design for layered semi-parallel decoding and a hardware framework of a layered semi-parallel LDPC decoder. The present invention removes a permutation network module between a check node and a variable node by modifying the cyclic shift value of each information block transferred from the variable node to the check node, i.e., the cyclic shift operation of the decoder can be completed through the single permutation network so as to reduce hardware resources of the decoder. A semi-parallel decoding structure is adopted, and meanwhile, a pipeline is added between half layers. Compared with a decoder with a layered full-parallel structure, a decoder with a semi-parallel structure has the degree of parallelism of a variable node equal to only half of the code length but can achieve ¾ of the throughput as well as reduce hardware resources by half.

One example of layer-by-layer error correction can include iteratively error correcting the codeword on a layer-by-layer basis with the first error correction circuit in a first mode and determining on the layer-by-layer basis whether a number of parity errors in a particular layer is less than a threshold number of parity errors. The codeword can be transferred to a second error correction circuit when the number of parity errors is less than the threshold number of parity errors. The codeword can be iteratively error corrected with the first error correction circuit in a second mode when the number of parity errors is at least the threshold number of parity errors. The threshold number of parity errors can be at least partially based on an adjustable code rate of the first error correction circuit or the second error correction circuit.

The present disclosure provides techniques for bandwidth constrained communication systems with frequency domain information processing. A bandwidth constrained equalized transport (BCET) communication system can include a transmitter, a communication channel, and a receiver. The transmitter can include a pulse-shaping filter that intentionally introduces memory into a signal in the form of inter-symbol interference, an error control code (ECC) encoder, a multidimensional fast Fourier transform (FFT) processing block that processes the signal in the frequency domain, and a first interleaver. The receiver can include an information-retrieving equalizer, a deinterleaver with an ECC decoder, and a second interleaver joined in an iterative ECC decoding loop. The communication system can be bandwidth constrained, and the signal can comprise an information rate that is higher than that of a communication system without intentional introduction of the memory at the transmitter.

The disclosure relates to a method performed by an apparatus for decoding an encoded signal in a communication system according to an embodiment of the disclosure may include an operation of receiving an encoded signal including a plurality of codeword bits, an operation of determining a first log-likelihood ratio (LLR) for the plurality of codeword bits, and an operation of performing iterative decoding a predetermined number of times based the first LLR, and the plurality of codeword bits may include a codeword bit included in a first subset and a codeword bit included in a second subset, and the operation of performing iterative decoding may include determining a second LLR only for the codeword bit included in the first subset of the plurality of codeword bits, and estimating, based on the second LLR, a bit value only for the codeword bit included in the first subset.

A method for accelerating bit error correction in a receiver in a radio communication network, wherein the receiver is configured to update soft bit values associated with each code bit of a block code based on parallel parity checks. The method includes receiving a block code encoded message, and for any group of two or more rows of a parity-check matrix of the block code: when the two or more rows are non-overlapping: combining the two or more rows in a row group for parallel updating, updating, in parallel, the parity checks of the row group for the received message, and forming a message estimate based on the updated parity checks. Corresponding computer program product, apparatus, and receiver are also disclosed.

A wireless receiving device comprises a low-density parity check (LDPC) decoding circuit, comprising a circular shifter constructed and arranged to simultaneously process multiple code words of a parity check matrix configured for different wireless communication standards, including performing a cyclic shift operation of the multiple code words to align with one or more requisite check nodes of a decoder and a logic circuit at an output of the circular shifter constructed and arranged for a matrix larger than the parity check matrix and that includes components having excess hardware due to the construction and arrangement for the larger matrix to decode the multiple code words of the smaller parity check matrix for output to the one or more requisite check nodes.

Certain aspects of the present disclosure generally relate to methods and apparatus for decoding low-density parity check (LDPC) codes, for example, using a parity check matrix having full row-orthogonality. An exemplary method for performing low-density parity-check (LDPC) decoding includes receiving soft bits associated to an LDPC codeword and performing LDPC decoding of the soft bits using a parity check matrix, wherein each row of the parity check matrix corresponds to a lifted parity check of a lifted LDPC code, at least two columns of the parity check matrix correspond to punctured variable nodes of the lifted LDPC code, and the parity check matrix has row orthogonality between each pair of consecutive rows that are below a row to which the at least two punctured variable nodes are both connected.

Embodiments of the invention provide a variable node processing unit for a non-binary error correcting code decoder, the variable node processing unit being configured to receive one check node message and intrinsic reliability metrics, and to generate one variable node message from auxiliary components derived from said one check node message and intrinsic reliability metrics, the intrinsic reliability metrics being derived from a received signal, an auxiliary component comprising an auxiliary symbol and an auxiliary reliability metrics associated with said auxiliary symbol, wherein the variable node processing unit comprises: a sorting and redundancy elimination unit configured to process iteratively the auxiliary components and to determine components of the variable node message by iteratively sorting the auxiliary components according to a given order of the auxiliary reliability metrics and keeping a predefined number of auxiliary components comprising the auxiliary symbols that are the most reliable and all different from one another.

A decoding method includes a selection step of reading reception data from a storage unit in units of P words, of reproducing data based on a column weight of a P-column unit of a check matrix, of writing reproduced data into an intermediate value storage unit, and of reading data from as many applicable register files as a row weight on a row block-by-row block basis for row blocks generated by row-wise division of the check matrix; a first shifting step of shifting the data read; a parallel row operation step of performing a row operation in parallel on a word-by-word basis using data shifted; a second shifting step of shifting as many operational results as the row weight, obtained by the row operation, to undo the shifting; and a first update step of updating values in the intermediate value storage unit with operational results.

According to certain embodiments, a method is provided for fast layered decoding for Low-density Parity-Check (LDPC) codes with a Parity-Check Matrix (PCM) that includes at least a first layer and a second layer. The method includes reading, from a memory, Variable Node (VN) soft information, wherein the VN soft information is associated with a message from a VN to a Check Node (CN) of the second layer of the PCM. A new CN to VN message is calculated from the CN of the second layer of the PCM. New VN soft information is calculated for the VN. The new VN soft information is calculated based on the VN soft information and a new CN to VN message from a CN of the first layer to the VN and an old CN to VN message from the CN of the first layer to the VN such that the updating of new VN soft information is delayed by at least one layer. The fast layered decoding has lower decoding latency and utilizes the decoding hardware more efficiently than standard layered decoding techniques. This may be achieved by keeping the memory access and processing hardware units active simultaneously to avoid excess decoding latency. More specifically, certain embodiments may carry out memory access and computation process simultaneously, without any effort to make the row layers mutually orthogonal to each other. Another technical advantage may be that the proposed decoding algorithm adjusts the LLRs to partially account for deviations from the layered decoding due to non-orthogonal rows.