156results about "Error correction/detection using LDPC codes" patented technology

A method and apparatus for receiving a PPDU in a wireless LAN system are provided. Specifically, a receiving STA receives a PPDU from a transmitting STA via a first frequency band and decodes the PPDU. The PPDU includes a preamble and a data field. The first frequency band includes a first sub-block and a second sub-block. The data field includes first data for the first sub-block and second data for the second sub-block. The first data is generated based on data in which constellation mapping is performed on coded data bits. The second data is generated based on data obtained by replicating the first data and applying phase rotation to the data.

Disclosed is a method comprising, by a transmitter apparatus, partitioning (901) an input data stream to obtain a bit stream X1 and a bit stream X2; subjecting (902) the bit stream X2 to encoding by LDPC encoders, to obtain X2 parity bits, and X2 information bits; applying (903) SPC encoding to the X2 parity bits, together with the bit stream X1, to obtain sign bits, wherein the bit stream X1 is used as padding bits; subjecting (904) the sign bits, the padding bits, and the X2 information bits, to an interleaver operation to obtain an interleaver output; subjecting (905) the interleaver output to Gray mapping to form multiple consecutive quadratic amplitude modulation, QAM, symbols; modulating (905) the QAM symbols by quadratic amplitude modulation to obtain a modulated data stream; and transmitting (906) the modulated data stream via a radio access network or optical fibre communication network.

The present disclosure provides a system and a method for implementing rate recovery in the PUSCH and PDCH bit rate processing chain of network. The system packs log likelihood ratios (LLRs) data in such a way that for each equalized in phase and quadrature (IQ) symbols, a predetermined number of LLRs equal to the modulation order are packed. The system de-interleaves the packed LLRs by reading the most significant bit (MSB) LLRs row wise for the number of columns equal to the modulation order. The system uses a single buffer for de-interleaving, bit-deselection, and filler bit addition stages, thereby reducing memory requirement of the system. The system processes only a predetermined number of LLRs to a HARQ combining stage to optimize memory and reduce latency.

A transmitter is provided that shapes uniformly-distributed bits into a non-uniformly distributed bits according to a parity check matrix of a linear code such that a product of the parity check matrix and the non-uniformly distributed bits equals the uniformly-distributed bits. Similarly, receiver is provided that recovers the uniformly-distributed bits from the non-uniformly distributed bits through a multiplication of the non-uniformly-distributed bits with the parity check matrix.

Provided is a method (300) and a successive interference cancellation (SIC) based multi-user uplink receiver (200) for multi-user uplink transmission. The method comprises receiving (302) signal of one or more multiple-access (MA) scheme waveforms by a plurality of antennas (202.1, . . . , 202.R) from one or more users. The method further comprises determining (304) one or more effective channel matrices corresponding to the plurality of antennas. Thereby, the method comprises performing (306) channel equalization for signal received in a corresponding antenna by an effective channel matrix. Furthermore, the method comprises combining (308) the channel equalized signal. Subsequently, the method comprises detecting (310) Correctly Decoded Code Blocks (CCBs) and Wrongly Decoded Code Blocks (WCBs). Upon detecting CCBs and WCBs, the method comprises performing (312) the SIC on received signals from one or more users until all WCBs are converted to CCBs or a maximum number of threshold iterations are completed.

An LDPC code-based communication method and a communication apparatus are provided. There is a nested relationship between base graphs, so that a base graph of a small scale can be derived based on a base graph of a large scale. The communication apparatus may store a base graph of a largest scale. When another base graph needs to be used for encoding or decoding, the communication apparatus may derive a required base graph based on the base graph of the largest scale. In this way, content that needs to be stored by the communication apparatus can be reduced.

In one embodiment, a first codeword is generated by error correction encoding a first individual payload, and a second codeword is generated based on bits associated with a second individual payload, the bits interleaving with bits associated with the first individual payload. Another embodiment includes encoding individual payloads by, for example, low density parity check (LDPC) encoding to generate encoded bits, the encoded bits including a first encoded bit generated by encoding a first individual payload, and a second encoded bit generated by encoding a second individual payload, where the encoded bits include a first encoded bit generated by encoding the first individual payload, and a second encoded bit generated by encoding the second individual payload, where the encoded bits include a first encoded bit generated by encoding the first individual payload, and a second encoded bit generated by encoding the second individual payload. The bits associated with the first individual payload are combined with the second individual payload. The first codeword and the second codeword each include encoded bits based on bits associated with the first individual payload. The first codeword in these embodiments may be decoded independently of the second codeword, and may also be decoded in conjunction with the second codeword.

The invention provides a mode for constructing the LDPC basis matrix, the LDPC basis matrix can be obtained according to the storage matrix and the indication information used for indicating the corresponding relation between the rows of the storage matrix or the expected corresponding relation between the rows of the LDPC basis matrix, and in the process of obtaining the LDPC basis matrix, the LDPC basis matrix can be obtained according to the indication information. And the number of the total edges on the Tanner graph corresponding to the non-expanded columns is not changed. Therefore, through the mode provided by the invention, the calculation complexity of the LDPC code can be maintained, and particularly, the calculation complexity of the low-code-rate LDPC code can be reduced and the decoding efficiency can be improved in a scene of expanding from a high code rate to a low code rate.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive a reference signal for estimation of at least one parameter associated with generation of an adapted low density parity check (LDPC) graph. The UE may transmit an indication of an adapted LDPC graph that is based on at least one adaptation metric associated with the at least one parameter. The UE may receive, based on the adapted LDPC graph, a downlink shared channel communication. Numerous other aspects are described.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a low density parity check (LDPC) code may include a parity check matrix (PCM) with a lifted parity submatrix. The lifted parity submatrix may include an upper-triangular portion having non-zero diagonal elements, a high-degree column portion, an all-zero portion, and a remaining portion, resulting in improved encoding efficiency. In some aspects, a transmitter may encode, in a first encoding operation, the upper-triangular portion and the high-degree column portion, and the transmitter may encode, in a second encoding operation, the all-zero portion and the remaining portion of the lifted parity submatrix. The encoded lifted parity submatrix may be transmitted from the transmitter to a receiver in a PCM as part of an LDPC code. Additionally, a base graph PCM structure may be included in the remaining portion of the lifted parity submatrix. Numerous other aspects are described.

The invention provides a communication method and a related device. The complexity of geometric forming can be reduced. The method comprises the following steps: a first device obtains a bit sequence to be transmitted, and modulates the bit sequence based on a third modulation scheme to map the bit sequence to each constellation point in a third constellation point set to obtain a modulation symbol; and the first device sends the modulation symbol to the second device, and correspondingly, the second device receives the modulation symbol and demodulates the modulation symbol to obtain the bit sequence. Wherein a plurality of constellation points in the third constellation point set are non-uniformly distributed, the third constellation point set is similar to a first constellation point set corresponding to the first modulation scheme, the first constellation point set is a subset of a second constellation point set, and the second constellation point set is a set of a plurality of constellation points corresponding to a predefined second modulation scheme; the order of the second modulation scheme is higher than that of the first modulation scheme, and the order of the third modulation scheme is the same as that of the first modulation scheme.

The invention relates to a system and a method for a quasi-cyclic low density parity check (QC-LDPC) code with a 1 / 2 code rate. An apparatus may include a transmitter and one or more processors. The one or more processors may be configured to identify a first binary parity check matrix for a quasi-cyclic low density parity check (QC-LDPC) code according to a code rate of 1 / 2 and a code block size of 7776 bits, the first binary parity check matrix corresponding to a first exponential matrix. The one or more processors may be configured to encode data using the first binary parity check matrix. The transmitter may be configured to transmit the encoded data.

To secure favorable communication quality in data transmission using an LDPC code.SOLUTION: In group-wise interleaving, the LDPC code with a code length N of 69120 bits is interleaved in units of 360-bit bit groups. In group-wise deinterleaving, a sequence of the LDPC code after group-wise interleaving is returned to an original sequence. The present technology can be applied, for example, to a case of performing LDPC code-based data transmission and the like.SELECTED DRAWING: Figure 143

Methods, systems, and devices for wireless communications are described. The described techniques may enable a transmitting device to perform probabilistic shaping using an energy function that is independent of a modulation and coding scheme (MCS) used by the transmitting device. For example, the transmitting device may encode a set of information bits according to a probability distribution, the energy function, a symbol alphabet, and a shaping parameter. The transmitting device may generate a set of probabilities corresponding to the symbol alphabet based on an energy sequence computed using the energy function, where a quantity of terms in the energy sequence may be based on a shaping order. The transmitting device may indicate the shaping order to a receiving device.

The invention discloses a coding method and device and a decoding method and device. A sending end acquires a first bit sequence, performs LDPC coding on the first bit sequence based on a check matrix to obtain a second bit sequence, and outputs the second bit sequence. Correspondingly, the receiving end receives the to-be-decoded information of the second bit sequence, LDPC decoding is carried out on the to-be-decoded information of the second bit sequence based on the check matrix, and K1 information bits are obtained. Wherein the check matrix is determined based on the corresponding relation of the first information columns and the first base graph, and the column number of the first information columns is determined based on the number K1 of the information bits and the column number K of the information columns of the first base graph. According to the technical scheme provided by the invention, the code rate can be effectively improved.

An apparatus and method for multiplexing signals using layered division multiplexing are disclosed. A signal multiplexing apparatus according to an embodiment of the present invention includes a combiner configured to combine a core layer signal and an enhanced layer signal at different power levels, and a time interleaver configured to perform interleaving applied to both the core layer signal and the enhanced layer signal.

An apparatus may include a receiver and one or more processors. The receiver may receive log likelihood ratio (LLR) values corresponding to encoded data that is encoded using a low-density parity-check (LDPC) code. The one or more processors may identify a number of punctured parity bits corresponding to the encoded data, determine that the number of punctured parity bits is less than a threshold, and remove, from a first parity check matrix corresponding to the encoded data, one or more rows corresponding to the number of punctured parity bits to generate a second parity check matrix. The one or more processors may determine, using the LLR values and the second parity check matrix, that there is an error in the LLR values, and an LDPC decoder may decode, based at least on the determination, the LLR values to resolve the error.

An apparatus (e.g., a transmitter) may transmit a message and one or more retransmissions of the message in a wireless communication network. The message may include a codeword that includes information bits and error correction bits (e.g., parity bits). The one or more retransmissions may include error correction bits associated with the information bits. To improve the decoding performance at a receiver, the transmitter may apply probabilistic shaping to the one or more retransmissions. In some aspects, the apparatus transmits a first message including information bits and a first set of error correction bits associated with the information bits. The apparatus transmits at least a second message associated with the first message, wherein the second message includes a second set of error correction bits associated with the information bits and a set of probabilistic shaping bits for the second set of error correction bits.

Embodiments of this application disclose an interleaving method supporting unequal modulation, a subcarrier mapping method supporting unequal modulation, and a related apparatus. An interleaver includes a first interleaver and a second interleaver, the interleaver is configured to determine an order of information bits carried in a subcarrier of a first RU and a subcarrier of a second RU, and a modulation scheme of the first RU is different from a modulation scheme of the second RU. The first interleaver is configured to input information bits by row. A quantity of columns of the first interleaver is M1+M2, a quantity of rows of the first interleaver is a larger value in N1 and N2, N1 and M1 are determined based on a quantity of subcarriers of the first RU, and N2 and M2 are determined based on a quantity of subcarriers of the second RU. The second interleaver is configured to receive the information bits that are output by the first interleaver by column, and perform interleaving mapping on the information bits. According to the interleaver provided in embodiments of this application, information bits of a plurality of RUs using different modulation and coding schemes can be interleaved, to simplify a hardware structure of a communication apparatus.

Communication systems are described that use unequally spaced constellations that have increased capacity compared to conventional constellations operating within a similar SNR band. One embodiment is a digital communications system including a transmitter transmitting signals via a communication channel, the transmitter including a coder capable of receiving user bits and outputting encoded bits at a rate, a mapper capable of mapping encoded bits to symbols in a constellation, and a modulator capable of generating a modulated signal for transmission via the communication channel using symbols generated by the mapper, wherein the constellation is unequally spaced and characterizable by assignment of locations and labels of constellation points to maximize parallel decode capacity of the constellation at a given signal-to-noise ratio so that the constellation provides a given capacity at a reduced signal-to-noise ratio compared to a uniform constellation that maximizes the minimum distance between constellation points of the uniform constellation.

This disclosure describes systems, methods, and devices related to for low-density parity-check (LDPC) Wi-Fi coding and decoding. A device may identify a first base matrix to generate LDPC codewords of 1944 bits; identify a mask matrix to generate a second base matrix based on the first base matrix used to generate LDPC codewords of 3888 bits, the entries of the mask matrix having values of 0, 1, and −1; generate the second base matrix by multiplying each the first base matrix by the mask matrix, the entries of the second base matrix indicative of respective cyclic shifts to apply to an identity matrix; generate a parity check matrix by multiplying the second base matrix by the identity matrix; generate a LDPC codeword of 3888 bits based on the parity check matrix; and transmit a frame including the LDPC codeword.

Apparatus, methods and systems for communication and sensing in multi-static sensing may be provided. According to an aspect a method 800 for transmitting a multistatic sensing PPDU may be provided. The method 800 includes generating, by processing electronics in an initiator 801, a multistatic sensing PPDU 804. The multistatic sensing PPDU 804 may be an IEEE 802.11 multistatic sensing PPDU, e.g., PPDU 300. The IEEE 802.11 multistatic sensing PPDU may include a data field, a sync field following the data field, a training field (TRN) following the sync field, and a PSDU Length field included in an EDMG-Header-A of the PPDU. The PSDU Length field may be set by the apparatus to have a value according to particular described equations and specifications.

Systems and methods for processing bit-interleaved coded modulation (BICM) signals from a BICM transmitter to generate information bit estimates of information in the BICM signals, including a decoder to generate the information bit estimates of the information in the received BICM signals and a symbol a posteriori probability (APP) generator to generate first symbol a posteriori probabilities (APPs) by processing the BICM signals based on symbol probability log-likelihood ratios (SPLLRs) provided to the symbol APP generator by an extrinsic-information-based symbol probability log-likelihood ratio (SPLLR) generator. The SPLLR generator generates the SPLLRs directly from extrinsic information based on updated symbol APPs output from the decoder, without converting the extrinsic information into log-likelihoods (LLs), and the decoder generates the information bit estimates based on the first symbol APPs output from the symbol APP generator.

This application provides an LDPC base graph construction manner. An LDPC base graph may be obtained based on a storage matrix and indication information that indicates a correspondence between rows of the storage matrix or a correspondence between rows of the expected LDPC base graph. In addition, in a process of obtaining the LDPC base graph, a total quantity of edges that correspond to non-extended columns and that are in a Tanner graph may not be changed. Therefore, the manner provided in this application helps maintain calculation complexity of an LDPC code, and in particular, helps reduce calculation complexity of an LDPC code in a scenario in which a high code rate is extended to a low code rate, to improve decoding efficiency.

The present disclosure relates to a 5G or 6G communication system for supporting higher data transfer rates than 4G communication systems such as LTE. The present invention relates to a method performed by a transmitter in a communication system, the method comprising the steps of: determining the number of input bits; determining a base matrix on the basis of the number of input bits; determining a lifting size (Z) on the basis of at least one of the number of input bits or the base matrix; determining a parity check matrix on the basis of at least one of the base matrix and the lifting size (Z); and performing encoding on the basis of the parity check matrix and the input bits, wherein the parity check matrix includes a first submatrix corresponding to the input bits and a second submatrix corresponding to first parity bits, three cyclic permutation matrices are included in a first column block of the second submatrix, the greatest common divisor of at least one of difference values of each exponent of the cyclic permutation matrices and the lifting size (Z) is 1 or the smallest number greater than 1 among divisors of the lifting size (Z), and the at least one of the difference values of each exponent of the cyclic permutation matrices is Z / 2' (0≤i≤L), where Z = p*2' (p is an odd number, 0≤i≤L).

This application discloses a modulation / demodulation and encoding / decoding method and belongs to the field of communication technologies. The modulation and encoding method includes: grading to-be-transmitted bits into a plurality of levels; encoding a plurality of levels of bits obtained through grading to obtain a plurality of levels of codewords; and mapping the plurality of levels of codewords to a symbol in a staggered manner, where the plurality of levels of codewords include a first codeword, the first codeword is located at a Yth level of the plurality of levels of codewords, and the first codeword overlaps at least one codeword at any level other than the Yth level. In this way, codewords at different levels are associated by using a symbol to which the codewords are mapped, and an overlapping part between a plurality of codewords can assist in demodulating the codewords.

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.

A data processing method is provided. The method may be applied to the field of communication technologies, and the method includes: generating a check block, where the check block is determined based on first bit sequences respectively corresponding to a plurality of code blocks, the first bit sequence is a part of a second bit sequence, and the second bit sequence is an encoded bit sequence of the code block corresponding to the first bit sequence; and sending the check block and the code blocks. In this way, error correction performance is improved when assisting in code block recovery.