96results about "Error correction/detection using LDPC codes" patented technology

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.

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 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.

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.

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.

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).

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.

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 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.

Methods, systems, and devices for reporting redundancy version with feedback information. are described. A user equipment (UE) may transmit, to a base station, feedback information corresponding to a code block group in conjunction with an indication of a redundancy version for retransmission of the code block group. The UE may monitor for the retransmission of the code block group based on the indication of the redundancy version for the retransmission of the code block group. The UE may then decode the retransmission of the code block group based on the monitoring and the redundancy version for the retransmission of the code block group.

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.

An apparatus (105) includes a transmitter (120) and one or more processors (2010). The one or more processors (2010) is configured to identify, according to a code rate of 1 / 2 and a code block size of 7776 bits, a first binary parity check matrix for a quasi-cyclic-low-density parity-check, QC-LDPC, code, the first binary parity check matrix corresponding to a first exponent matrix. The one or more processors (2010) encode data using the first binary parity check matrix. The transmitter (120) transmits the encoded data.

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.

A method and apparatus for generating broadcast signal frames are disclosed herein. An embodiment of the present invention provides an apparatus for generating broadcast signal frames, comprising: a combiner configured to generate a multiplexed signal by combining a core layer signal and an enhancement layer signal; a power normalizer configured to reduce the power of the multiplexed signal to a power level corresponding to the core layer signal; a time interleaver configured to generate a time-interleaved signal by performing time interleaving applied to both the core layer signal and the enhancement layer signal; and a frame builder configured to generate broadcast signal frames, wherein the broadcast signal frames include a preamble for signaling start position information and size information for each physical layer channel (PLP) in a physical layer channel (PLP). In this case, the physical layer channels include a core physical layer channel corresponding to the core layer signal and an enhancement physical layer channel corresponding to the enhancement 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.

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.

An apparatus for use by an OLT communicatively connected to an ONU includes means for interleaving a first number N of codewords according to a predetermined interleaving scheme to obtain an interleaved bit stream, where N is an even number; mapping the interleaved bit stream to a 4-level pulse amplitude modulation (PAM4) label sequence according to a predetermined mapping scheme, where a respective PAM4 label includes a least significant bit (LSB) and a most significant bit (MSB) that respectively correspond to bits in the interleaved bit stream; transmitting, to the ONU, a PAM4 symbol sequence generated based on the PAM4 label sequence; wherein bits from a respective codeword of the N codewords are assigned to LSBs of a first subset of labels and MSBs of a second subset of labels, where the first subset of labels and the second subset of labels are determined based on the predetermined interleaving scheme and the predetermined mapping scheme and respectively include labels that are N labels apart in the PAM4 label sequence.

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.

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 decoding performance at the receiver, the transmitter may apply probabilistic shaping to one or more retransmissions. In some aspects, an apparatus sends 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 probabilistically shaped bits for the second set of error correction bits.