687 results about "Polar code" patented technology

The invention discloses a coder based on repeated coding and channel polarization and a coding / decoding method thereof. The coder comprises two coding modules with the same structure; each coding module is provided with a repeated coder group, a bit position mapper with the length of N and a channel polarization device with the length of N, wherein the repeated coder group has m*L output ports and is composed of L sequentially-arranged repeated coders with the repeating times of m; and the two coding modules are connected together through a coding mode selector between the repeated coder and the bit position mapper. The invention provides a concrete method of embedding repeated codes in the channel polarization process to perform channel coding and decoding based on the coder; and compared with the polarization code of the limited length in the prior art, the coding / decoding method disclosed by the invention has stronger error correction capability and obviously improves the transmission performance on the premise of rarely increasing the decoding complexity, is particularly suitable for the practical engineering systems of mobile communication, satellite communication, underwatercommunication and the like, and has good popularization and application prospects.

The invention discloses a polarization code and multi-bit even parity check code cascaded error correction coding method. The method comprises the steps: a transmitting end encoder utilizes a multi-bit even parity check code as an outer code, and utilizes a polarization code as an inner code; a receiving end decoder decodes by utilizing a modified successive cancellation list (SCL) decoding algorithm. On the aspect of error correction performance, comparing with the prior art utilizing middle-short code length non-cascaded polarization codes of the SCL decoding algorithm, the polarization code and multi-bit even parity check code cascaded error correction coding method has the advantages that frame error rate performance of a system can be remarkably improved, and a maximum likelihood bound (ML Bound), which cannot be broken through by the SCL decoding algorithm, can be remarkably broken through. On the aspect of engineering realization, according to the polarization code and multi-bit even parity check code cascaded error correction coding method, the outer code utilizes the multi-bit even parity check code, which is simple to code; the modified SCL decoding algorithm is utilized to decode, bit decision and even parity check are combined to be carried out in a decoding process, and compared with the original SCL decoding algorithm, the method provided by the invention does not increase the decoding complexity, and facilitates the engineering realization.

The invention discloses a quantum key distribution after-treatment system and a quantum key distribution after-treatment method based on polar code correction. The system comprises a key screening module, a parameter estimation module, a polar code correction module, a consistency verification module and a privacy amplification module which are connected in sequence. The method comprises the following steps: only keeping original keys with the same base selection to form screening keys after quantum bite information is transmitted on a quantum channel; commonly selecting partial key bits from the screening keys to perform disclosed comparison; coding and decoding undisclosed key bits by adopting a system polar code algorithm under the condition that the quantum bit error rate is not higher than a safety threshold value; verifying the consistence of the corrected quantum keys by adopting cryptographic algorithm; and calculating safety information entropy and performing information compression to obtain absolutely safe key bits. The quantum key distribution after-treatment system has linear coding / decoding complexity characteristics, so that the after-treatment time delay and key length increase have linear relationship, and the after-treatment speed is improved.

The invention provides a polarization code coding method, a decoding method, a coding device and a decoding device. The coding method comprises the following steps: a coding device generates a first bit sequence according to target information needing to be transmitted to a decoding device, wherein the first bit sequence includes information bits and fixed bits, and the information bits are used to carry the target information, and the fixed bits are used to carry preset information; the coding device determines a check bit according to the first bit sequence; the coding device generates a second bit sequence according to the first bit sequence and the check bit; and the coding device generates a polarization code sequence according to the second bit sequence. Decoding delay can be reduced, and the user experience can be improved.

The invention discloses a self-adaptive continuous erasure decoding method and architecture based on a polarization code. The method comprises the following steps: selecting a SCA-SCL decoder when a signal to noise ratio (SNR) is less than a specific threshold value, or selecting an adaptive SCL decoder; and performing the decoder conversion by use of a switching mechanism when a list length is greater than the specific threshold value. By use of the method disclosed by the invention, the optimal condition of two decoder working modes is selected, and the existing combined logic circuit architecture is not greatly changed, so that the architecture is universal and general, popular and easy to understand; not only is the performance of the decoder improved, but also is the complexity of the decoder lowered.

In view of a polar code, the embodiment of the invention provides a new serial list decoding algorithm based on bit flipping. In view of the problem of error propagation in a serial cancellation list coding algorithm (CA-SCL) for assisting cyclic redundancy check, error bits appearing for the first time on the original error path are flipped to enable the error path to become a correct path. Compared with the CA-SCL algorithm, although the new algorithm has a little loss in the space complexity and the decoding complexity, the performance is greatly enhanced, and 0.3 dB coding gains can be realized as much as possible, and while the security is ensured, the convenience is improved.

The present invention provides a serial offset list bit flip decoding method for a polarization code, which comprises the following steps: a first step of constructing a bit flip index set; a second step of decoding the received signal formula with a CRC-SCL decoder; and a third step of performing SCLF decoding. The serial offset list bit flip (Successive cancellation list flip, SCLF) decoding method for THE polarization code proposed by the present invention is an improved method for the existing SCF and CRC-SCL decoding methods, the SCLF method introduces the concept of bit flipping into theCRC-SCL decoder, thereby further improving the performance of the CRC-SCL decoder. That is, the CRC-SCL decoder can still take remedial measures after finding a decoding failure, so that the currentdecoding is successful.

The invention provides an efficient multi-scheme ECC technology based on a polar code. The technology is called as a pre-detection scheme and used for meeting the actual application requirements and reducing decoding delay. According to the technology, balance between the decoding speed and the performance requirements can be achieved by judging the voltage diffusion condition of a current NAND flash memory and selecting a corresponding polar code decoder (such as a hard decision decoder, a quantitative soft decision decoder and a pure soft decision decoder) for different voltage distribution states.

The invention relates to a nonuniform quantizing coding method used for decoding an LDPC code and the application of the method in a decoder. The method comprises the steps that the quantification range of messages L(rji), L(qij) and L(Qi) is determined according to information distribution of an initial message L(Pi), a coding mode is adopted for performing nonuniform quantizing on the messages L(rji), L(qij) and L(Qi), quantized intervals of positive number portions and negative number portions are respectively divided into m sections, coding is a codon composed of 1-bit polar codes, k-bit segment codes and (n-1-k)-bit in-segment codes, the polar codes mark positive numbers and negative numbers, the segment codes mark different segments, the segment internal codes show specific size of the data in the segments, each segment is divided into 2<g> small segments, and the small segments are the quantized intervals of the corresponding segments. According to the method, consumption of hardware storage resources, operation processing units and locating and wiring resources is reduced, quantization errors of small-value data are reduced, and the decoding performance is improved.

The invention discloses a parallel decoding method and device for polarization codes, belongs to the field of wireless communication, and particularly relates to a parallel decoding method for polarization codes. Based on the defect of high decoding delay of a Fast-SSC algorithm, the invention provides a parallel quick method, two parallel Fast-SSC decoders are adopted, channel information is divided into two parts during decoding, and decoding is performed by the two parallel decoders, so that the decoding delay of the Fast-SSC algorithm is effectively reduced. The method has the same bit error rate as the Fast-SSC algorithm, but is faster in decoding speed than the Fast-SSC algorithm; and when the two Fast-SSC decoders are parallel, the parallelism is improved by about 40% over the Fast-SSC algorithm.

The invention discloses a hybrid automatic repeat request method based on a polarization code and a device using the same. The method comprises the following step: when repeat is initiated automatically under the condition of transmission failure, first transmission bit sequences polarization-coded at a certain code rate are linearly combined to get second transmission bit sequences, wherein the code rate of the second transmission bit sequences is lower than that of the first transmission bit sequences. The second transmission bit sequences are set to linear combination of the first transmission bit sequences. After second transmission, soft information received through two times of transmission is serially combined according to a certain way. Decoding is performed with a lower-rate and longer polarization code. Certain coding gain is achieved while diversity gain is obtained.

The invention relates to the technical field of channel encoding, in particular to Polar code encoding cooperation based on inverse code word Plotkin construction and information bit re-hibernation. The encoding cooperation based on Polar codes is researched from the aspects of sub-code word construction way, performance optimization and the like. Plotkin construction is performed on non-system Polar inverse code words from the aspect of sub-code word construction to obtain an encoding cooperation method based on inverse sub-code words, so that the performance of non-system Polar code encoding cooperation is improved remarkably under a fading channel. From the aspect of performance optimization, an information bit re-hibernation mechanism is introduced by analysis of a decoding feature of the inverse sub-code word, so that the cooperation benefit is increased; and then, encoding cooperation based on non-system Polar codes is extended to encoding cooperation based on system Polar codes. The method and the system have the beneficial effects that the inverse code word Plotkin construction, the information bit re-hibernation and the system Polar codes are introduced, so that the performance of the Polar codes is improved remarkably compared with the prior art under a slow fading channel.

Decoding and encoding methods, systems, and devices for wireless communication are described. One method may include receiving a codeword over a wireless channel, the codeword being encoded using a polar code, identifying a set of repeated bit locations in the received codeword, and identifying a set of bit locations of the polar code used for information bits for the encoding. The set of bit locations may be determined based at least in part on recursively partitioning bit-channels of the polar code for each stage of polarization and assigning portions of a number of the information bits to bit-channel partitions of each stage of polarization based on a mutual information transfer function of respective aggregate capacities of the bit-channel partitions. The method may also include decoding the received codeword according to the polar code to obtain an information bit vector at the set of bit locations, and other aspects and features.

The invention discloses a polar code BP decoding method and device based on multi-stage updating processes. A hardware device is mainly composed of a BP decoder, a controller, a processing element module, an early iteration stopping module and a storage. The decoding method comprises the steps of: (S1), pre-setting the maximum iteration time of the BP decoder; (S2), decoding polarization by usinga multi-stage flooding BP decoding algorithm; and (S3), performing CRC check on a decoding result in an iteration process, wherein if the CRC check is passed, the decoder stops iteration and outputs the decoding result; and otherwise, iteration is continuously carried out till the time is up to the maximum iteration time. According to the polar code BP decoding method and device based on the multi-stage updating processes provided in the invention, parallel decoding through multiple sets of PEs having opposite initial iteration directions is used; therefore, the iteration time is further reduced under the early iteration stopping standard; a test result is displayed in a range of 2-3.5 dB; therefore, the average iteration time is reduced by 31.7-36.5%; and the decoding delay is effectivelyreduced.

The invention discloses a single-step quantum key distribution post-processing method and system based on a polarization code, a medium and equipment. The system comprises a secret key screening module, an error code calculation module, a polarization code construction module, a polarization code coding module, a polarization code decoding module and a consistency checking module, and the method comprises the steps that a sending end and a receiving end carry out base comparison on an original secret key to obtain a screened secret key; a quantum bit error rate is calculated through error codeestimation, and if the quantum bit error rate is smaller than a threshold value, remaining screened keys are reserved; a quantum bit error rate is combined with reliability and safety conditions to construct a polarization code word structure, and system polarization code coding generates coded code words corresponding to check bits and random bits; and the receiving end receives the encoded codeword and combines the reserved key bits to obtain a decoded bit value through decoding, wherein decoded bit value and the encoded codeword corresponding to the key bit of the sending end constitute akey pair, carries out consistency verification, and obtains the final secret key, so that the post-processing time consumption and the system complexity are reduced, and the final secret key generation rate of quantum secret key distribution is improved.

The invention discloses a multi-stage bit interleaved coded modulation method based on a polarization code, which mainly aims at a communication system under a complex Gaussian channel and comprises two parts of contents: polarization code coding and design of a bit-to-symbol mapping rule. In polar code coding, firstly, by designing sub-modulation orders of all levels, a traditional binary kernelcan be used for polar code coding of all levels, punching and construction of a multi-core polar code are avoided, and the polarization performance of the polar code is guaranteed. And then, calculating the reliability of the bit polarization channel through external information transfer, and selecting the high-reliability bit polarization channel to transmit information bits, thereby finishing polarization code coding. The design of a bit-to-symbol mapping rule mainly aims at mapping of a symmetric constellation diagram, and is hybrid mapping of joint set decomposition and Gray mapping. According to the invention, by designing the mapping rule from bits to symbols, the polarization performance can be improved to the maximum extent, so that the group error rate performance of the system isimproved.

The invention relates to the technical field of mobile communication, in particular to an improved polar code serial elimination list bit flipping decoding method and system, and the method comprisesthe steps: inputting an initialized log likelihood ratio LLR into a decoder for decoder path selection, and screening out L paths for CRC verification; determining a fixed key flipping index set SCSS,and determining an improved key flipping index set ICSS according to a threshold of simulation statistics; if the bit index in the decoding process belongs to the ICSS, performing bit flipping to obtain L paths after bit flipping; performing CRC (cyclic redundancy check) on the L paths after bit flipping, and if the L paths pass the CRC, determining that decoding succeeds; and if the CRC is not passed, changing the bit flipping index, and returning to the decoding iteration process. According to the method, the number of elements in the key flipping index set is reduced in a threshold segmentation mode, and the key flipping index set is optimized.

The cascaded polarization code bit inverting belief propagation encoding and decoding method is suitable for being used in the technical field of channel encoding in wireless communication, messages are transmitted between LDPC and polarization codes through a BP decoding method, and the correct rate of information transmission through an unreliable channel is increased; under the condition that BP decoding fails, a bit inverting decoding method is used for selecting unreliable information bit judgment through a pre-constructed key set, and the prior log-likelihood ratio of unreliable channelinformation bits is set to be an infinite value; by trying to correct error information propagation in the BP decoder, the error rate performance of the cascade code under the BP decoding method is improved. According to the method, the accuracy of key set inverting is effectively improved, the group error rate can be greatly improved, and the group error rate performance is remarkably improved; and meanwhile, the decoding time delay is not increased, and the gain of the bit error rate performance can be obtained at the cost of relatively small decoding time delay.

The embodiment of the invention provides a data transmission method which comprises the steps of: carrying out polar code encoding on to-be-encoded bits to obtain a mother code, wherein a code length of the mother code is related to K and Mi, i=1, 2,..., K, K represents sending times, Mi represents a length of bits sent at an ith time, and K and Mi are positive integers greater than 1; carrying out rate matching on the mother code to obtain to-be-sent bits, wherein the number of the to-be-sent bits is a sum of lengths of bits sent for K times; and sending Mi to-be-sent bits at the ith time. By utilizing sending times in the polar code encoding process, the mother code which further accords with the actual transmission demands can be obtained, so that encoding amplification of a polar code can be sufficiently utilized; and moreover, a signaling does not need to be sent in real time to request for retransmission, so that signaling cost can be reduced.

The invention provides a low-time-delay polar code decoder combined with deep learning, and particularly, compared with a simplified Successive cancellation list (SSCL) decoder, the low-time-delay polar code decoder has the advantage that the number of calculation times is smaller. The decoder comprises five modules, namely a normal SCL calculation module, a Rate-0 calculation module, a Rep calculation module, a Rate-1 calculation module, and a DNN calculation module of a common node. The SSCL decoder combined with the deep neural network retains the original low decoding delay characteristicof Rate-0, Rate-1 and Rep nodes, a deep neural network is used for decoding common nodes to reduce the decoding delay, and finally the purpose of reducing the overall decoding delay is achieved. Experimental calculation shows that when the code length is 64 and the code rate is 1 / 2, the decoding delay is reduced by about 27% compared with the decoding delay of the SSCL.

The invention discloses a PS-64-QAM IMDD transmission method and system based on polar code coding. The method is used in a transmitting end, and comprises the steps: inputting binary bits which are uniformly distributed into a PS encoder, and creating a transmission mode lookup table, thereby generating K data bits and M selection bits; performing pseudo-random interleaving operation on the K bits, and inputting the K bits into a system polarization code encoder. The invention has the beneficial effects that experiments prove that in an IM / DD 64-QAM OFDM transmission system, the performance of the system is greatly improved through probability shaping and PAPR suppression in combination with system polarization code error correction. It can be seen that 7dB and 4dB performance improvements are obtained under the condition that the BER is 3.8 * 10 <-3 > before FEC and after FEC according to the scheme of the invention. Moreover, the redundant information of the PS and the SLM is skillfully put into the frozen bit of the polar code, so the redundancy of the whole transmission system is ensured to be constant.

The application provides a coding method of a Polar code. The method comprises the following steps: enabling sending equipment to determine a punctured bit sub-channel, determining J' second types of auxiliary bit sub-channels in combination with a table look-up mode, and after determining the first type of auxiliary bit sub-channels and information bit sub-channels, performing Polar coding for a sequence to be coded. Through the mode, the overhead of real-timely computing the reliability degree can be effectively reduced, the time can be saved, and the delay can be reduced.

The invention discloses a polar code segment coding method. The method comprises the following steps: determining a coded code length N according to a to-be-coded information bit number and a code rate; according to the N, the minimum segment code length and the maximum segment code length, determining the reserved segment number of each segment in the segments with the b-a+1 segment code lengthsand the reserved code length corresponding to the N, wherein the minimum segment code length is 2[Lambda]a, and the maximum segment code length is 2[Lambda]b; determining the segment number of each segment according to N, the reserved code length, the segment code length of each segment and the reserved segment number of each segment, wherein N corresponds to an S segment, and the segment code length of the ith segment in the S segment is larger than or equal to the segment code length of the (i+1)th segment in the S segment; determining a target information bit number of the S-segment segmentaccording to the code rate and the segment code length of the S-segment segment; and performing polarization code encoding on the information bits to be encoded according to the target information bit number of the S segments. By implementing the invention, the performance of the low-power-consumption communication system can be effectively improved under the condition of meeting the decoding andreporting delay limitation.

The invention provides a soft demodulation method of a linear frequency modulation spread spectrum modulation technology. The method comprises FFT transformation processing and orthogonal binary peakdifference soft demodulation, and the orthogonal binary peak difference soft demodulation process comprises the following steps: S1, respectively finding out a first symbol subscript set with the ithbit being 0 and a second symbol subscript set with the ith bit being 1 in a transformation result; S2, determining soft information of the ith bit after demodulation according to a first maximum amplitude in all amplitudes corresponding to the first symbol subscript set and a second maximum amplitude in all amplitudes corresponding to the second symbol subscript set; and S3, starting from i=0, increasing i progressively, and repeating the steps S1 and S2 until all bits are traversed. The method has the advantages that the problem that soft information is needed in the decoding process when Turbo codes, LDPC codes, Polar codes and the like are used for replacing Hamming codes in LoRa is solved; cascading conditions are provided for Turbo+CSS, LDPC+CSS, Polar+CSS and other physical layer schemes, a series of enhanced LoRa communication systems are constructed, and the communication capacity of LoRa is greatly improved.

The invention provides an underwater acoustic communication method using a polarization code and an equalizer. An underwater acoustic channel is converted into a Gaussian channel through the equalizer to construct the polarization code, and an HARQ mechanism is added to improve the performance of the scheme. According to the scheme, the bit error rate performance is superior to the result of turbo equalization iteration for five times, the decoding complexity is low, the coding structure is simple, and only noise variance information needs to be fed back when a polarization code receiving end is constructed by using a Gaussian approximation method.

Embodiments of this disclosure enhance the error detection performance of parallel polar encoding by cross-concatenating parity bits between segments of information bits transmitted over different sets of sub-channels. In one embodiment, a first segment of information bits is transmitted over a first set of sub-channels, and at least a second segment of information bits, and a masked parity bit, are transmitted over a second set of sub-channels. A value of the masked parity bit is equal to a bitwise combination of a first parity bit computed from the first segment of information bits and a second parity bit computed from the second segment of information bits. The bitwise combination may be a bitwise AND, a bitwise OR, or a bitwise XOR of the respective parity bits.

The embodiment of the invention provides a polar code decoding method and device based on a neural network. The method comprises the following steps: obtaining a polarization code to be decoded, the polarization code being obtained by performing polarization coding on an uncoded sequence, the uncoded sequence being composed of information bits of K bits and frozen bits of (N-K) bits, N = 2n, n being a positive integer, and K being a positive integer less than N; inputting a polarization code to be decoded into the neural network model to obtain a decoding sequence; wherein the neural network model is obtained by training based on a preset training set, and the preset training set comprises a sample polarization code and a sample uncoded sequence. By applying the technical scheme provided by the embodiment of the invention, after the neural network model is trained, the error between the decoding sequence of the sample polar code and the uncoded sequence of the sample is adjusted to bewithin an acceptable range, so that the bit error rate of polar code decoding can be reduced; in addition, parallel decoding can be carried out by using the neural network model, and the delay time ofpolar code decoding is reduced.

The invention discloses an SC-BP hybrid decoding method for a polar code and an adjustable hardware architecture thereof, comprising the following steps of: processing the channel log-likelihood ratioof an input through a k-order SC decoder to obtain the input log-likelihood ratio of a BP decoder; iterating the input to obtain an output of the BP decoder, wherein the k is a decomposition factor of a hybrid decoder; encoding and returning the output to the SC decoder as a returned value of the SC decoder; and performing the next decoding operation according to the returned value by the SC decoder. The SC-BP hybrid decoding method for a polar code integrates the SC decoder algorithm and the BP decoder algorithm into an SC-BP hybrid decoding unit and adds the pre-computing technology, so that under the effects of an SC encoding feedback architecture and an hybrid decoding systolic architecture, the time delay and the performance of the decoding can be rounded between the effects of the SC and the BP algorithms, the decoder can adapt to multiple communication requirements, and the market application prospect is excellent.