117 results about "Low-density parity-check code" patented technology

The invention discloses an image encryption system and method in an intelligent power grid environment, and aims to solve the problem that an encryption strategy is static and lacks self-adaptive capability in the prior art. The image encryption system comprises terminal equipment, edge equipment and central equipment, and a dynamic key generation unit on the terminal equipment generates a dynamic key by cooperatively utilizing a physical unclonable feature (PUF) of the equipment and a real-time load of a power grid; the hierarchical encryption unit performs encryption of different intensities based on image content complexity. A topology sensing transmission module of the system analyzes power grid topology by using a graph neural network (GNN) and dynamically optimizes transmission. In addition, the image encryption system further integrates low-density parity check code encoding and decoding and a self-adaptive decryption strategy so as to enhance the anti-interference capability. According to the invention, by constructing a sensing, decision-making and execution integrated adaptive security system, the security, high efficiency and robustness of smart grid image data transmission are significantly improved.

This application provides a rate matching method and a communication apparatus. A transmit end punctures an LDPC codeword based on a priority order of check bits of a mother code of an LDPC code. The priority order of the check bits of the mother code indicates a priority order of puncturing the check bits in a rate matching process, and the priority order is related to confidences of the check bits. The confidences of the check bits indicate degrees to which the check bits are affected by noise in a channel transmission process. In addition, puncturing the check bits can ensure restorability of a system variable node, and a check bit with a higher confidence is more likely to be correctly restored, so that more valid information can be provided for another system variable node during decoding iteration.

The invention discloses a soft decoding method and device, a medium and a product, and relates to the technical field of error correction coding, and the method is applied to a low-density parity check code, and comprises the steps: obtaining a target low-density parity check code with an information node and a check node containing an erasure bit; and allocating a preset non-zero log-likelihood ratio to the erasure bit on the check node, and executing first soft decoding. And if the first soft decoding fails, judging whether to carry out second soft decoding or not based on the weight of the syndrome generated by the first soft decoding and the number of the erasure bits on the information node. If it is judged that the second soft decoding needs to be carried out, a preset non-zero log likelihood ratio is distributed to the erasure bit located on the information node, and the second soft decoding is carried out. According to the method and the device, the erasing bits on different nodes are conditionally processed in stages, so that the success rate and the efficiency of decoding are effectively improved.

This application provides example concatenated code encoding and decoding methods. In one example method, polar code encoding is performed on a to-be-encoded message bit sequence based on a frozen bit set and a message bit set that are of a first polar code, to obtain a first encoded code word whose length is N_o. The first encoded code word is interleaved to obtain a second encoded code word, and optimized low-density parity-check (LDPC) code encoding is performed on the second encoded code word to obtain a concatenated code word. Interleaving includes both outer interleaving and inner interleaving. The concatenated code word is then outputted.

The invention provides a backtracking-based spatial coupling low-density parity check code decoding method. The backtracking-based spatial coupling low-density parity check code decoding method comprises the following steps: acquiring a code word sequence of a spatial coupling low-density parity check code to be decoded according to set parameters; performing side information initialization on the decoding window, executing belief propagation decoding in the decoding window, and performing judgment when the number of iterations reaches the set minimum number of iterations; and determining the decoding position and the window size of a decoding window in the next step according to a judgment result until all target symbols in the code word sequence are decoded. According to the invention, the error propagation phenomenon in the space coupling LDPC code sliding window decoding process can be effectively improved, and the sliding window decoding performance is improved.

An apparatus may include a transmitter and one or more processors configured to identify a code rate of a low-density parity-check (LDPC) code, receive, by an LDPC encoder, a set of information bits and encode, using the code rate, the set of information bits to generate a set of encoded bits and a set of parity bits, generate, from the set of encoded bits, a matrix of bit arrays, discard one or more parity bits from the set of parity bits to generate a parity bit array with a size equal to a number of column of the matrix, generate a bit array by concatenating (1) one or more bit arrays selected from the matrix of bit arrays and (2) one or more bits selected from the parity bit array corresponding to the one or more bit arrays, and modulate, by a modulator, the bit array to generate modulated data.

Certain aspects of this disclosure generally relate to techniques for enhanced puncturing and low-density parity-check (LDPC) code structures. A method for wireless communication by a transmitting device is provided. This method generally includes: encoding a set of information bits based on an LDPC code to generate a codeword, the LDPC code being defined by a basic matrix having a first number of variable nodes and a second number of parity nodes; puncturing the codeword according to a puncturing pattern designed to puncture bits corresponding to at least two of the variable nodes to generate a punctured codeword; adding at least one additional parity bit to the punctured at least two variable nodes; and transmitting the punctured codeword.

Methods, systems, and devices for wireless communication are described. The method may include a first wireless device generating one or more low density parity check (LDPC) codewords and adding one or more symbols or one or more symbol fractions to adjust a first boundary of a packet such that a puncturing ratio associated with the one or more LDPC codewords is reduced or set to zero. In some examples, the first boundary may specify a first number of symbols of the packet allocated for the one or more LDPC codewords. Further, the first wireless device may transmit, to a second wireless device, the packet comprising the one or more LDPC codewords based on the adjusted first boundary.

The invention relates to the technical field of wireless communication, and discloses an adaptive LDPC code coding method, system and device based on evaporation waveguide field intensity distribution, and a medium, and the method comprises the steps: obtaining the evaporation waveguide field intensity distribution in real time, and generating a field intensity distribution diagram; calculating a channel state parameter, and dynamically selecting a low-density parity check code rate according to the channel state parameter information; dynamic low-density parity check coding is adopted, and a sparse structure is adjusted through a check matrix, so that real-time switching of multi-code-rate low-density parity check codes is carried out; and a receiving end carries out decoding by adopting an NW-RBP decoding algorithm, defines a node updating rule, and dynamically schedules a node updating sequence through a residual error. According to the method, the bit error rate under a complex channel is reduced, and meanwhile, the reliable transmission efficiency of system data is improved.

The application provides a low-density parity-check code decoding method and device based on a graph neural network, which comprises the following steps: step 1, constructing a factor graph comprising variable nodes, check nodes and edge relationships, and mapping log-likelihood ratio information of a received signal to initial embedding of the variable nodes; step 2, generating message features according to node embedding, node degree and iteration step length, and constructing attention weights for each edge to measure the importance of the message; step 3, inputting the message features and the attention weights into a gated recurrent unit to update the residual of the edge weight, and feeding back the updated edge weight to the graph structure; step 4, weighting and aggregating the messages from the adjacent nodes according to the edge weight, calculating the updated embedding of the variable nodes and the check nodes, and performing gated modulation combined with the check result; step 5, repeating steps 2 to 4 until a preset iteration number or a decoding convergence condition is reached, and mapping the final variable node embedding to a decoding result to realize LDPC code word recovery. By introducing the attention mechanism and the gated residual update into the message passing process, the application realizes adaptive modeling of the contribution degree of different edge messages, dynamically remembers the historical state, thereby improving the decoding performance and the convergence speed; meanwhile, the application can effectively reduce the bit error rate and is suitable for high-speed reliable data transmission scenarios in a 5G / 6G wireless communication system.

An apparatus may include a transmitter. The apparatus may identify a target code rate and a low density parity check (LDPC) code that has a base code rate for a base size of information bits, select, based at least on the target data rate and the base code rate, a first size that is less than the base size of information bits, generate a second set of information bits to include a first set of information bits corresponding to the first size and one or more bits to increase a size of the second set of information to correspond to the base size of information bits, encode, using the base code rate, the second set of information bits to generate parity data, and generate a codeword by concatenating the first set of information bits and the parity data to achieve the target code rate. The transmitter may transmit the codeword.

A channel coding method and apparatus. In the method, a sending apparatus performs low-density parity-check code (LDPC) coding on an input bit sequence on the basis of a first base graph that includes a first core matrix and corresponds to a first initial transmission code rate, so as to obtain a coded bit sequence, wherein the first base graph is one of N base graphs; the N base graphs further comprise a second base graph; the second base graph includes a second core matrix and corresponds to a second initial transmission code rate; N is an integer greater than or equal to 2; elements in the first base graph are zero elements and non-zero elements, and elements in the second base graph are zero elements and non-zero elements; the number of rows of the first base graph is equal to the number of rows of the second base graph, and the number of columns of the first base graph is equal to the number of columns of the second base graph; the second initial transmission code rate is less than the first initial transmission code rate; and the number of rows of the second core matrix is greater than the number of rows of the first core matrix. The method can reduce the complexity of channel coding and channel decoding.

A method for very high coding rates for next generation wireless local area network (WLAN) systems involves coding input data at a first coding rate to provide coded data, the coding input data at a first coding rate being based on a second coding rate, wherein the second coding rate is lower than the first coding rate and the second coding rate coding uses low density parity check codes. The method also involves wirelessly transmitting the coded data.

In some implementations, an apparatus may include a transmitter and one or more processors. The one or more processors may identify a plurality of resource units (RUs) used for transmitting respective data streams within one or more wireless channels. The one or more processors may determine, based at least on a difference in signal quality between transmissions across the plurality of RUs, respective target code rates for the plurality of RUs. The respective target code rates may be different from each other and different from a base code rate of a low density parity check (LDPC) code. The one or more processors may encode, by an LDPC encoder using the LDPC code with the base code rate, the respective data streams to generate respective encoded data streams at the respective target code rates. The transmitter may transmit the respective encoded data streams using the plurality of respective RUs.

Embodiments of the present invention relate to a communication method, a communication device, and a communication system. The communication method is applied to a first device, and comprises: determining a first radio frame, the first radio frame comprising first identification information, and the first identification information identifying whether the first device supports a low-density parity-check code (LDPC) data encoding mode having a codeword length of 3844 bits; and sending the first radio frame. The first identification information is used for identifying whether the first device supports the LDPC data encoding mode having the codeword length of 3844 bits, so that a 2×LDPC transmission rule is used in data transmission, thereby improving data transmission efficiency and meeting service transmission requirements.

The present invention discloses a memory device and a memory controller. The memory controller includes a control unit, a storage unit, and a plurality of encoder units. The storage unit is coupled to the control unit and includes a plurality of storage areas. Each storage area is represented by a memory address and stores one of a plurality of parts of a generator matrix. The encoder units are coupled to the control unit and the storage unit and are coupled to the memory chips one-to-one, many-to-one, or one-to-many. The encoder units are based on a low density parity check (LDPC) code, and the LDPC code is based on the generator matrix.

Systems and methods for performing low-density parity-check (LDPC) coding may include a wireless communication device that determines a low density parity check (LDPC) codeword length from among a predetermined set of codeword lengths, according to a payload bit count corresponding to a plurality of information bits. The wireless communication device may determine a number of LDCP codewords according to the payload bit count and the selected LDCP codeword length. The wireless communication device may provide, via an LDPC encoder, the number of LDPC codewords, each LDPC codeword encoding a respective portion of the plurality of information bits and having the selected LDPC codeword length.

The invention relates to a self-adaptive SPA decoding method for low density parity check LDPC code decoding, and belongs to the technical field of signal processing. According to the method, a decoding strategy is adaptively selected according to the signal-to-noise ratio, and a simplified SPA decoding algorithm for reducing the calculation amount through residual calculation is provided, so that the decoding efficiency is improved, and the calculation complexity is reduced. Specifically, when the signal-to-noise ratio is lower than a preset threshold value, the algorithm adopts a simplified SPA decoding strategy, and in the strategy, first 15% of check nodes with the maximum influence are selected for updating by utilizing residual errors, so that the calculated amount of each iteration is reduced; and when the signal-to-noise ratio is higher than the threshold value, the algorithm is converted to use a standard SPA decoding strategy, so that higher decoding accuracy is ensured. Through the mode of dynamically selecting the decoding strategy, the average time of each iteration can be obviously reduced under the condition of low signal-to-noise ratio, and extra calculation complexity caused by residual error sorting is avoided under the condition of high signal-to-noise ratio.

Embodiments of the present application provide a method for communication, a device, a storage medium, and a program product. In the method, a decoding apparatus decodes a low density parity check (LDPC) code on the basis of a belief propagation (BP) algorithm to obtain an initial bit sequence that does not satisfy a parity-check equation set. In addition, the decoding apparatus performs multiple bit flipping operations on a predetermined bit range of the initial bit sequence to obtain a plurality of flipped bit sequences. In one bit flipping operation, at least one bit in the predetermined bit range is flipped. In addition, the decoding apparatus performs LDPC encoding on the plurality of flipped bit sequences to obtain a plurality of candidate bit sequences. Furthermore, the decoding apparatus determines, from among the plurality of candidate bit sequences, a target bit sequence meeting a predetermined condition as a decoding result of the LDPC code. In this way, a certain degree of randomness is introduced by performing bit flipping within the predetermined bit range, thereby resisting the influence of noise or interference, improving decoding performance, and reducing complexity.

A data encoding method includes, writing information bits into at least two cache blocks, where the cache blocks store parity bits corresponding to the information bits, and two adjacent bits of data of the parity bits are stored in different cache blocks; and performing low density parity check code (LDPC) encoding according to the information bits and the parity bits in the cache blocks.

Communication systems and methods are disclosed that utilize Probability Amplitude Shaping (PAS) and Trellis Coded Modulation (TCM) to transmit short block-length messages. While capacity-approaching codes, such as Low Density Parity Check (LDPC) codes, Turbo codes, and Polar codes, can achieve data rates approaching the Shannon limit at large block-lengths, the performance of these codes can deteriorate dramatically at short block-lengths. Communication systems configured in accordance with various embodiments of the invention can utilize classical codes to encode short block-length messages to achieve communication rates exceeding Polyanskiy's Random Coding Union bound. In several embodiments, message bits are transmitted using a TCM system in which message bits that have been previously encoded by an error detection code are encoded using a convolutional code (CC). In a number of embodiments, the error detection code and the CC are obtained via a joint optimization with respect to a Frame Error Rate bound.

The present disclosure provides coding and decoding methods, a communication device, and a storage medium. The coding method, applied to a first transmission node, includes: determining a base matrix for low density parity check (LDPC) coding from a preset base matrix set; performing LDPC coding on original data according to the base matrix, so as to obtain coded data; transmitting the coded data to a second transmission node; wherein the base matrix includes two kinds of elements: an element indicating an all-zero square matrix, and an element indicating a cyclic shift of an identity matrix; the base matrix set includes at least two non-empty subsets of base matrices, and all base matrices in each subset of the at least two non-empty subsets of base matrices have a same coding rate.

The invention discloses a switch division multiple access passive random access method and system based on protograph joint information source channel coding, and relates to the technical field of communication, and the method comprises the steps: carrying out joint information source channel coding based on protograph low density parity check codes on binary information source sequences of a plurality of activated users, and determining corresponding code word sequences; selecting a plurality of check bits from each code word sequence to respectively construct a switching mode control sequence, and correspondingly mapping the switching mode control sequence into an activated decimal switching mode index value; selecting a switching mode from a preset switching mode matrix according to an associated activation decimal switching mode index value for a modulation sequence generated by modulation of each codeword sequence, mapping the selected switching mode into a sending symbol, and sending the sending symbol in a superposed manner; and detecting and decoding the received symbol sequence, and outputting a decoded signal source sequence of each activated user. Based on the scheme, efficient and reliable transmission of non-uniform information sources in a large-scale machine type communication scene is realized.

The invention discloses a channel coding method and device, and the method comprises the steps that a transmitting device carries out the LDPC coding of an input bit sequence based on a first base graph which corresponds to a first initial transmission code rate and comprises a first core matrix, and obtains a coded bit sequence; wherein the first base graph is one of N base graphs, the N base graphs further comprise a second base graph, the second base graph comprises a second core array and corresponds to the second initial code transmission rate, and N is an integer larger than or equal to 2. The elements in the first base graph are zero elements and non-zero elements, and the elements in the second base graph are zero elements and non-zero elements. The row number of the first base graph is equal to that of the second base graph, and the column number of the first base graph is equal to that of the second base graph. The second initial code transmission rate is smaller than the first initial code transmission rate, and the line number of the second core array is larger than the line number of the first core array. The method can reduce the complexity of channel coding and channel decoding.

A method for performing data access control for a host device includes: receiving a plurality of host commands from the host device, for performing data access on at least one medium according to the plurality of host commands, wherein the data access includes data receiving; and performing a data access optimization procedure for maintaining correctness of the data receiving that includes: performing the data receiving on the at least one medium to obtain at least one code word; performing multiple first low-density parity-check (LDPC) code decoding operations regarding multiple column segments, where a portion of column segments are abnormal column segments corresponding to puncture variable nodes; finding at least one column segment satisfying predetermined selection condition, to perform at least one second LDPC code decoding operation regarding the at least one column segment; performing multiple third LDPC code decoding operations regarding the multiple column segments; and returning error-free data.

The invention relates to a self-adaptive LDPC (Low Density Parity Check Code) decoding method, device and equipment based on dynamic adjustment. The method comprises the following steps: after information data to be decoded are transmitted to check nodes, calculating residual errors of edges connected with the check nodes; when the residual error is greater than a preset initial threshold value, updating the check node by adopting a BP algorithm, otherwise, updating the check node by adopting an MS algorithm; counting the number of the check nodes updated by adopting the BP algorithm after updating, reducing the size of the initial threshold when the number of the nodes is greater than the number of iteration nodes in the last round, increasing the size of the initial threshold when the number of the nodes is zero, and otherwise, maintaining the size of the initial threshold; and after message transmission of the check nodes and the variable nodes is completed, counting total information of the check nodes, performing decoding judgment based on the total information, outputting a decoding result when the decoding judgment is passed or reaches the maximum number of iterations, and otherwise, performing the next round of iteration. By adopting the method, both performance and decoding efficiency can be considered.

Input data is received for storage by a system. The input data is encoded using a low-density parity-check (LDPC) matrix to generate encoded data, wherein the LDPC matrix is selected from a plurality of LDPC matrices, each of the plurality of LDPC matrices having a common size and a unique degree distribution. The encoded data is then stored on a memory device of the system.

The disclosure relates to systems and methods for providing multiple code rates across resource units in a communication system. In some embodiments, an apparatus may include a transmitter and one or more processors. The one or more processors may identify a plurality of resource units (RUs) for transmitting respective data streams within one or more wireless channels. The one or more processors may determine respective target code rates for the plurality of RUs based at least on signal quality differences between transmissions across the plurality of RUs. The respective target code rates may be different from each other and from a base code rate of a low density parity check (LDPC) code. The one or more processors may encode, by an LDPC encoder, the respective data streams using the LDPC code having the base code rate to generate respective encoded data streams at the respective target code rate. The transmitter may transmit the respective encoded data streams using the plurality of respective RUs.

The present application relates to the technical field of data verification, and in particular, to a method for decoding a low-density parity-check code. The method includes: combining the input codeword information with a preset low-density parity-check matrix for initialization to obtain initialized decoding information, and obtaining the eigenvalues of each row of the initialized decoding information; calculating the check node check values of each non-zero element in the current column of the initialized decoding information according to the eigenvalues; performing decoding based on all the check node check values in the current column and the codeword information to obtain the decoding result of the current column; obtaining the historical decoding result, calculating the syndrome according to the historical decoding result, if the syndrome is 0, the decoding is successful and the decoding result is output; if the syndrome is not 0, all the eigenvalues are updated, and then the next column is used as the current column, and the step of calculating the check node check values of each non-zero element in the current column of the initialized decoding information is executed according to the eigenvalues. Decoding by column reduces the requirement for storage space.