54results about "Error correction/detection using LDPC codes" patented technology

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.

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.

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.

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.

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).

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.

In an embodiment, a first codeword is generated by error correction encoding a first individual payload, and a second codeword is generated based on bits that are associated with a second individual payload and are interleaved with bits associated with the first individual payload. Another embodiment involves encoding individual payloads, by low density parity check (LDPC) encoding for example, to generate encoded bits including first encoded bits generated by encoding a first individual payload and second encoded bits generated by encoding a second individual payload with which bits that are associated with the first individual payload are combined. Each of the first codeword and the second codeword includes encoded bits based on the bits that are associated with the first individual payload. The first codeword in these embodiments is decodable independently of the second codeword, and is further decodable jointly with the second codeword.

Various arrangements for improving performance of code split communications are presented herein. A second portion of a first codeword and a third portion of a second codeword can be transmitted using symbols such that each transmitted symbol includes bits from the second portion of the first codeword and bits from the third portion of the second codeword. At a receiver, decoder inputs can be generated for the third portion of the second codeword based on an optimized constellation and the second portion of the first codeword. The second portion of the first codeword is used to identify a label group of the optimized constellation and eliminate all other label groups of the plurality of label groups. Within each label group, symbol labels are Gray labeled. However, at least a first symbol label is not Gray labeled with an adjacent second symbol label of a different label group.

In some implementations, a transmitting UWB device may determine a number of information bits of a payload to communicate via UWB. The transmitting UWB device may select, based on the number of information bits, a codeword length from a selection of available codeword lengths with which to encode the payload using a low-density parity-check (LDPC) encoding scheme, wherein the selection of available codeword lengths include a first codeword length, a second codeword length, and a third codeword length, wherein the third codeword length is longer than the second codeword length, which is longer than the first codeword length. The transmitting UWB device may transmit the payload using one or more codewords having the selected codeword length.

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.

In some implementations, an apparatus may include a transmitter and one or more processors. The one or more processors may be configured to identify, according to a code rate of 1 / 2 and a code block size of 3888 bits, a first binary parity check matrix for a quasi-cyclic-low-density parity-check (QC-LDPC) code. The first binary parity check matrix may correspond to a first exponent matrix having 288 values. The one or more processors may be configured to encode data using the first binary parity check matrix. The one or more processors may be configured to transmit the encoded data.

A method of wireless communication includes sending, from a first device to a second device, first capability information identifying at least one code rate supported by a first low density parity check (LDPC) code, encoding a signal based on the first capability information and the first LDPC code in response to sending the first capability information, and sending the signal encoded based on the first capability information and the first LDPC code.

To ensure good communication quality in data transmission using LDPC codes. [Solution] In group-wise interleaving, an LDPC code with a code length N of 69120 bits is interleaved in units of 360-bit bit groups, with the (i+1)th bit group from the beginning of the LDPC code being bit group i, and the arrangement of bit groups 0 to 191 of the 69120-bit LDPC code being interleaved in a predetermined order. In group-wise deinterleaving, the arrangement of the LDPC code after group-wise interleaving is restored to its original order. This technology can be applied, for example, to data transmission using LDPC codes.

A method of a first communication node may comprise: storing a compressed channel message in an APP memory, based on a signal received from a second communication node; generating a first V2C message using a first APP message and a first C2V message respectively obtained from the APP memory and a C2V memory, in a VNP process; obtaining a first minimum vector and a second minimum vector by performing CW sorting on the first V2C message, in a CNP process; performing normalization on the first V2C message based on the first minimum vector, in the CNP process; and obtaining a third minimum vector by performing RW sorting on the second minimum vector based on the first minimum vector, in the CNP process.

A wireless communication method by a first device, the method includes transmitting, to a second device, first capability information that identifies at least one code rate supported by a first low density parity check (LDPC) code, and receiving a signal that is encoded based on the first capability information and the first LDPC code.

This application provides a communication method and a related apparatus, to reduce complexity of geometric shaping. The method includes: A first device obtains a to-be-transmitted bit sequence; 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 modulated symbol. The first device sends the modulated symbol to a second device. Correspondingly, the second device receives the modulated symbol; and demodulates the modulated symbol, to obtain the bit sequence. 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 a first modulation scheme, the first constellation point set is a subset of a second constellation point set, the second constellation point set is a set of a plurality of constellation points corresponding to a predefined second modulation scheme, an order of the second modulation scheme is higher than an order of the first modulation scheme, and an order of the third modulation scheme is the same as the order of the first modulation scheme.

Provided is a transmitter that shapes uniformly distributed bits into 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 is equal to the uniformly distributed bits. Similarly, a receiver is provided that restores uniformly distributed bits from non-uniformly distributed bits by multiplication of the non-uniformly distributed bits with a parity check matrix.

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.

An encoding method, a decoding method, and an apparatus are provided. A transmit end obtains a first bit sequence, performs LDPC encoding on the first bit sequence based on a check matrix, to obtain a second bit sequence, and outputs the second bit sequence. Correspondingly, a receive end receives to-be-decoded information of the second bit sequence, and performs LDPC decoding on the to-be-decoded information of the second bit sequence based on the check matrix, to obtain Ki information bits. The check matrix is determined based on a correspondence of a first information column and a first base graph, and a quantity of columns in the first information column is determined based on the quantity Ki of information bits and a quantity K of information columns in the first base graph. The technical solutions provided in this application can effectively increase a code rate.

In some implementations, a transmitting UWB device may determine a number of information bits of a payload to communicate via UWB. The transmitting UWB device may select, based on the number of information bits, a codeword length from a selection of available codeword lengths with which to encode the payload using a low-density parity-check (LDPC) encoding scheme, wherein the selection of available codeword lengths include a first codeword length, a second codeword length, and a third codeword length, wherein the third codeword length is longer than the second codeword length, which is longer than the first codeword length. The transmitting UWB device may transmit the payload using one or more codewords having the selected codeword length.

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-Aof the PPDU. The PSDU Length field may be set by the apparatus to have a value according to particular described equations and specifications.

This disclosure provides systems, methods and apparatus, including computer programs encoded on computer storage media, for encoding data for wireless transmissions. In one aspect, a wireless device may encode a number (M) of systematic bits for transmission to a receiving device. The systematic bits may be encoded using a quasi-cyclic low-density parity-check (QC-LDPC) code to produce an LDPC codeword. The LDPC codeword may include a number (N) of codeword bits, including the M systematic bits and one or more parity bits. The wireless device may further puncture a number (K) of the codeword bits (systematic and / or parity bits) to produce a punctured codeword having a code rate M / (N-K) > 5 / 6, e.g M / (N-K) = 7 / 8. The wireless device may transmit the N-K remaining codeword bits, over a wireless channel, to a receiving device.

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 Euclidean distances derived from the BICM signals, and further based on symbol probability log-likelihood ratios (SPLLRs) provided to the symbol APP generator by an extrinsic-information-based symbol probability log-likelihood ratio (SPEER) generator. The SPEER 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.

The disclosure relates to a 5G or 6G communication system supporting a higher data transmission rate than the previous 4G communication system, such as LTE.

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.