86 results about "List decoding" patented technology

Embodiments of the present invention provide a decoding method and a decoding apparatus for a polar code. The method comprises: grouping a first polar code having a length of N into s second polar codes, a length of each second polar code being N/s, N and s being integer powers of 2, and N>s; performing path splitting of list decoding on s second polar codes concurrently, and combining split paths of s second polar codes after path splitting, so as to obtain multiple combined paths having a length of N; choosing a first combined path from multiple combined paths having a length of N bits, the first combined path being a path having the greatest path metric value among the multiple combined paths having a length of N bits, or a path passing cyclic redundancy check (CRC) among the multiple combined paths having a length of N bits; and obtaining a decoding result of the first polar code according to the first combined path. In this case, a decoding throughput of the polar code can be improved, and a decoding delay can be decreased.

Various embodiments are described of a system and method for improved SCL decoder operation. In particular, various embodiments are described which improve the efficiency of the buffer management based on updated path metric statistics. In some embodiments, the SCL decoder may perform selective replacement to limit the extent of LLR updates per row only to the statistics that have changed since the previous update cycle. In some embodiments, the SCL decoder may perform deferred updates, which may involves in-place calculation of both û_φ=0 and û_φ=1 bit estimate (LLR) updates based on the row from which the updated row will be derived.

Systems and methods are provided for implementing various aspects of a Reed-Solomon (RS) error-correction system. A detector can provide a decision-codeword from a channel and can also provide soft-information for the decision-codeword. If the decision-codeword corresponds to an inner code and an RS code is the outer code, a soft-information map can process the soft-information for the decision-codeword to produce soft-information for a RS decision-codeword. A RS decoder can employ the Berlekamp-Massey algorithm (BMA), list decoding, and a Chien search, and can include a pipelined architecture. A threshold-based control circuit can be used to predict whether list decoding will be needed and can suspend the list decoding operation if it predicts that list decoding is not needed.

Two decoding algorithms are introduced for the decoding of multi-level coded modulation and other types of coded modulation involving component codes and interleaving operations. An improved hard iterative decoding (IHID) algorithm is presented that improves upon a hard iteration decoding technique by adding a stopping criterion. Also, a list Viterbi hard iteration decoding (LV-IHID) algorithm is presented that employs list decoding in conjunction with the IHID algorithm. Both of these decoding algorithms improve upon conventional multi-stage decoding by reducing the effective error multiplicity that is observed at the lowest coding level. It is demonstrated that the LV-IHID algorithm performs close to soft iterative decoding. The computational and delay complexity of the proposed decoding algorithms compare favorably with soft iterative decoding strategies. Also, a novel labeling strategy for MLC design is presented.

The invention discloses a polarization code belief propagation list decoding method based on bit flipping. Code words used in the method are cascade codes formed by CRC codes and polarization codes. According to the method provided by the invention, under the condition that the BPL decoding result does not pass the CRC check, a decoding result in a BPL decoding method is analyzed, a Flip Bits Set (FBS) is constructed, and information bits, located in the FBS, of the polarization codes are flipped (bit flipping is achieved by setting the prior log-likelihood ratio of flipped bits to be infinite). Errors in part of BPL decoders can be corrected, and then the bit error rate and the frame error rate performance of the BPL decoding method are improved.

The invention provides a rapid optimization method for polarization code decoding parameters. The method comprises the following steps of firstly, starting from collection and sorting of sample data;then carrying out modeling according to the characteristics and the size of the sample data, and adopting a supervised learning and random gradient optimization method for training a network; then inputting the likelihood ratio obtained by calculation of the received signal into a radial basis function neural network model which completes the training and outputting M; and finally, initializing Lto M and executing a serial offset list decoding algorithm. According to the method, a radial basis function neural network technology and a polarization code decoding technology are combined, so thatunnecessary calculation operation is avoided, and therefore the coding complexity of polarization codes is greatly lowered.

Two decoding algorithms are introduced for the decoding of multi-level coded modulation and other types of coded modulation involving component codes and interleaving operations. An improved hard iterative decoding (IHID) algorithm is presented that improves upon a hard iteration decoding technique by adding a stopping criterion. Also, a list Viterbi hard iteration decoding (LV-IHID) algorithm is presented that employs list decoding in conjunction with the IHID algorithm. Both of these decoding algorithms improve upon conventional multi-stage decoding by reducing the effective error multiplicity that is observed at the lowest coding level. It is demonstrated that the LV-IHID algorithm performs close to soft iterative decoding. The computational and delay complexity of the proposed decoding algorithms compare favorably with soft iterative decoding strategies. Also, a novel labeling strategy for MLC design is presented.

The invention discloses a self-adaptive fusion serial cancellation list polarization code decoding method and a self-adaptive fusion serial cancellation list polarization code decoding system. The method comprises the following steps: obtaining bits in a to-be-decoded sequence; screening out information bits in the sequence to be decoded; judging whether the log-likelihood ratio of each information bit meets a positive threshold judgment condition which is greater than 0 and greater than a positive threshold or a negative threshold judgment condition which is less than 0 and less than a negative threshold one by one according to the arrangement sequence of the coded bit sequence to obtain a first judgment result; when the first judgment result is negative information bits, the informationbits of which the arrangement sequence is before the information bits of which the first judgment result is negative are decoded one by one by adopting a serial offset decoding method; and decoding the information bits with the first judgment result being no and all the bits behind the information bits one by one by adopting a cyclic redundancy auxiliary serial offset list decoding method. According to the invention, the average complexity of the adaptive serial cancellation list decoding method under a low signal-to-noise ratio can be reduced, and the low average complexity under a high signal-to-noise ratio can be maintained.

The invention discloses a joint decoding method and apparatus based on continuous elimination list decoding and list sphere decoding. According to the joint decoding method and apparatus disclosed bythe invention, the continuous elimination list decoding and the list sphere decoding are combined, decoding is performed from the first bit to the Mth bit by using a continuous elimination list decoding mode, and decoding is performed from the last bit to the (M+1)th bit by using a list sphere decoding mode; and in a matching phase, a path i in a list of the continuous elimination list decoding and a path j in a list of the list sphere decoding are respectively selected, an Euclidean distance between a synthetic code word and a receiving code word is calculated and matched, and the code word having the minimum Euclidean distance is selected as the output of the decoding method. The joint decoding method and apparatus disclosed by the invention have the advantages of lower delay and higherefficiency.

An apparatus and a method. The apparatus includes a receiver to receive a polar codeword of length m^j; a processor configured to determine a decoding node tree structure with m^j leaf nodes for the received codeword, and receive i indicating a level at which parallelism of order m is applied to the decoding node tree structure, wherein i indicates levels of the decoding node tree structure, and wherein the m^j leaf nodes are at level j; and m successive cancellation list decoders (SCLDs) applied to each child node of each node in the decoding node tree structure at level i−1, wherein each of the m SCLDs executes in parallel to determine log likelihood ratios (LLRs) for a codeword of length m^j−i, and wherein each of the m SCLDs uses LLRs of an associated parent node without using a hard decision or a soft reliability estimate of any other node of the other m SCLDs.

A method of decoding a barcode includes determining number of barcode candidates in the image captured and processing the image captured in accordance with the number of barcode candidates found. If the number of barcode candidates is one, the image captured is processed to decode the only one barcode candidate in the image captured. If the number of barcode candidates is larger than one, the image captured is processed to find a barcode candidate that overlays with an aiming location between a first location and a second location on a scan line and to decode the barcode candidate that is found that overlays with the aiming location.

The invention discloses an adaptive belief propagation list decoding method for polar codes. The method comprises: firstly, determining the number of BP decoders owned by a receiving end; determiningthe maximum list number of the method; obtaining a BP decoding factor graph capable of achieving a good decoding effect through calculation by a Gaussian approximation method; then, selecting different BP decoding factor graphs for decoding from the BP decoders recorded in the list; and sequencing the decoding results, then carrying out cyclic redundancy check, if a result passing through the cyclic redundancy check exists, determining that the decoding is successful and stopping the decoding, otherwise, automatically adjusting the size of the list, expanding the number of the list by two times of the original number, and continuing to use the BP decoder in the list to decode.

An application specific integrated circuit (ASIC) tangibly encodes a method for fast polynomial updates in fast Chase decoding of binary Bose-Chaudhuri-Hocquenghem (BCH) codes. The method includes the steps of using outputs of a syndrome-based hard-decision (HD) algorithm to find a Groebner basis for a solution module of a modified key equation, upon failure of HD decoding of a BCH codeword received by the ASIC from a communication channel; evaluating polynomials obtained from said Groebner basis at inverses of specified weak-bit locations; and transforming a Groebner basis for a set of flipped weak-bit locations (α₁, . . . , α_r−1) to a Groebner basis for (α₁, . . . , α_r), wherein α_r is a next weak-bit location, wherein r is a difference between a number of errors and a HD correction radius of the BCH codeword.

The invention discloses a polarization code serial cancellation list decoding method based on a simplified third-order critical set, and belongs to the technical field of channel coding in wireless communication. The method comprises the following steps: step 1, constructing a third-order critical set TCS, wherein the TCS is composed of the first 3 bits in all R1 nodes in the polarization code, and the R1 nodes refer to the nodes in a polarization code decoding binary tree where all leaf nodes represent information bits; step 2, constructing a simplified third-order critical set STCS; and step3, classifying decoding paths by the simplified third-order critical set STCS according to the decoding index, and performing separate decoding. By defining the simplified third-order critical set, the method only performs path splitting on information bits located in the STCS, and does not perform path splitting on information bits not located in the STCS, so as to reduce the number of splittingof the decoding paths, thereby reducing the number of path management in the CA-SCL decoder and reducing the time delay of the CA-SCL decoding method.

The invention discloses an improved polar code BP List decoding method which comprises the following steps: 1, selecting a factor graph set according to a factor graph error probability method; 2, selecting one factor graph from the factor graph set Z in sequence to perform BP decoding; 3, if the decoding is correct, ending the decoding; otherwise, executing the step 4; 4, if the factor graph is the last factor graph, determining that the decoding fails, and ending the decoding; otherwise, executing the step 5; 5, selecting two positions with the lowest reliability in the x end according to adecoding result in the current factor graph, namely selecting an unreliable position; 6, selecting an unreliable position symbol; and 7, updating the channel initial information, and then turning to the step 2 for execution. According to the method, the performance of BP decoding is close to the performance of CASCL8, the requirement of engineering application is met, meanwhile, the time delay ofthe algorithm can be effectively reduced through parallelization, and the time delay requirement is met.