669 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 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.

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 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 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 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 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 invention discloses a polarization code flipping decoding method and system based on deep learning, and belongs to the field of wireless communication. The method comprises the following steps: firstly, constructing a neural network unit and training, and then inputting soft information output by a decoding unit into the neural network unit to obtain a possible decoding error position; and then feeding back a possible decoding error position to the decoding unit, overturning a decoding result of the decoding error position by the decoding unit, and then restarting decoding until a decodingresult is obtained. The system comprises a neural network unit and a decoding unit, wherein the neural network unit is connected with the decoding unit; the decoding unit comprises a belief propagation unit, a verification unit and a turnover unit. According to the invention, the defects of high complexity and unsatisfactory performance of the traditional flip decoding algorithm in the prior artare solved, the decoding complexity is reduced, and different channel environments and configuration requirements of a communication system are met.

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 a system polarization code puncturing method and system based on reliability. The method comprises the steps of performing reliability calculation on a system polarization codewith a code length of N; assuming that an L bit needs to be shortened, firstly selecting the last L sub-channel as a first part of a frozen bit, taking the K sub-channel with the highest reliabilitymetric value as an information bit from the remaining (N to L) sub-channels, and taking the remaining sub-channels as a second part of the frozen bit; performing bit inversion replacement on the indexvalue of the first part of the frozen bit to obtain a codeword end punching vector index s; encoding the system polarization code; deleting codeword bits at corresponding positions according to the punching vector index s; transmitting the punctured system polarization code through a Gaussian channel; initializing a log-likelihood ratio corresponding to the punching index vector s to be infiniteat a decoding end; and evaluating the puncturing method. According to the invention, the system polarization code can adapt to different code lengths on the premise of not changing the basic structureof the system polarization code.

A transmission apparatus: encodes information into a first bit sequence, using a polar code; outputs a second bit sequence by inputting the first bit sequence to an interleaver; modulates the second bit sequence into modulation symbols according to a modulation order; and transmits the modulation symbols. The interleaver: has an odd number of columns; and is configured to cyclically read and output, from column k, bits stored in row n of the interleaver, and cyclically read and output, from column k+a, bits stored in row n+1 of the interleaver, wherein a represents an integer which is not 0.

The invention provides a rapid PDCCH blind detection method based on pruning SCL polar code decoding. The method comprises the following steps of: determining a search space type; calculating the initial position of the CCEs candidate set under the aggregation level, and obtaining the length and position of the whole CCE candidate set according to the CCE aggregation degree; carrying out demodulation, descrambling and rate de-matching on the CCEs candidate set; carrying out polar code decoding; calculating a bit LLR value; calculating PM; performing path expansion on the current bit; performing path pruning; and when N bit decoding is finished, enabling that the path corresponding to the maximum PM passes CRC verification, correct DCI is obtained if verification succeeds, and blind detection of the PDCCH is finished. According to the method, after the CCEs candidate set is selected by applying the proper blind detection process algorithm, the provided pruning SCL polar code decoding algorithm is adopted, and then CRC verification is performed, so that the performance is stable, and the blind detection efficiency is effectively improved.