A method for decoding an error correction code and an associated decoding circuit are provided, where the method includes the steps of: calculating a set of error syndromes of the error correction code, where the error correction code is a t-error correcting code and has capability of correcting t errors, and a number s of the set of error syndromes is smaller than t; sequentially determining a set of coefficients within a plurality of coefficients of an error locator polynomial of the error correction code according to at least one portion of error syndromes within the set of error syndromes for building a roughly-estimated error locator polynomial; performing a Chien search to determine a plurality of roots of the roughly-estimated error locator polynomial; and performing at least one check operation to selectively utilize a correction result of the error correction code as a decoding result of the error correction code.

A soft-decision decoding computes a first syndrome polynomial in accordance with a received word, computes a second syndrome polynomial by multiplying the first syndrome polynomial by a locator polynomial based on locations of erasures within the received word, finds a basis and private solution to an affine space of polynomials that solve key equations based on the second syndrome polynomial, determines a weak set of a locations of symbols in the received word with confidence below a certain confidence level, computes a matrix from the basis, the private solution and the weak set, determines sub-matrices in the matrix whose rank is equal to a rank of the matrix, determines error locator polynomial (ELP) candidates from the sub-matrices, the basis, and the private solution, and corrects the received word using a selected one of the ELP candidates.

A decoder includes a syndrome calculator, a Key Equation Solver (KES) and an error corrector. The syndrome calculator receives an n-symbol code word encoded using a Reed Solomon (RS) code to include (nk) redundancy symbols, calculates for the code word 2t syndromes Si, t=(nk)/2 is a maximal number of correctable erroneous symbols. The KES derives an error locator polynomial {circumflex over ()}(x) whose roots identify locations of erroneous symbols, by applying to the syndromes a number of t iterations. In each iteration the KES calculates two discrepancies between {circumflex over ()}(x) and respective two candidates of {circumflex over ()}(x), and derives from the two candidates an updated candidate of {circumflex over ()}(x). The error corrector recovers the code word by correcting the erroneous symbols using the derived error locator polynomial {circumflex over ()}(x).

A decoding method includes that when encoding at a sending terminal, for a m-order primitive polynomial P(x), a primitive field element in galois field GF(2.sup.m) is represented by ; a lookup table f(.sup.j) for different power exponents of is established, where the value of j is selected from all the integers ranging from 0 to 2m1, with a total number of 2m; a generator polynomial G(x) is expanded to obtain a polynomial with respect to x, with coefficients being an addition or subtraction of the power exponents of ; a remainder polynomial R(x), obtained by dividing code word polynomial Q(x) by the generator polynomial G(x), is a polynomial with respect to x, with coefficients being an addition or subtraction of the power exponents of ; and the coefficients of the generator polynomial G(x) and the remainder polynomial R(x) are both calculated using data found in the lookup table f(.sup.j).

Embodiments of the present disclosure provide a high speed low latency rate configurable soft decision and hard decision based pipelined Reed-Solomon (RS) decoder architecture suitable for optical communication and storage. The proposed RS decoder is a configurable RS decoder that is configured to monitor the channel and adjust code parameters based on channel capacity. The proposed RS decoder includes interpolation and factorization free Low-Complexity-Chase (LCC) decoding to implement soft-decision decoder (SDD). The proposed RS decoder generates test vectors and feeds these to a pipelined 2-stage hard decision decoder (HDD). The proposed RS decoder architecture computes error locator polynomial in exactly 2t clock cycles without parallelism and supports high throughput, and further computes error evaluator polynomial in exactly t cycles. The present disclosure provides a 2-stage pipelined decoder to operate at least latency possible and reduced size of delay buffer.

A system comprises a forward error correction decoder comprising syndrome computation circuitry, key-equation solver circuitry, and search and evaluator circuitry. The syndrome computation circuitry may comprise a plurality of syndrome compute units connected in parallel. The syndrome computation circuitry may be dynamically configurable to vary a quantity of the syndrome compute units used for processing of a codeword based on conditions of a channel over which the codeword was received. The syndrome computation circuitry may be operable to use a first quantity of the syndrome compute units for processing of a first codeword received over the channel when the channel is characterized by a first bit error rate and a second quantity of the syndrome compute units for processing of a second codeword received over the channel when the channel is characterized by a second bit error rate.

A method for decoding an error correction code and an associated decoding circuit are provided, where the method includes the steps of: calculating a set of error syndromes of the error correction code, where the error correction code is a t-error correcting code and has capability of correcting t errors, and a number s of the set of error syndromes is smaller than t; sequentially determining a set of coefficients within a plurality of coefficients of an error locator polynomial of the error correction code according to at least one portion of error syndromes within the set of error syndromes for building a roughly-estimated error locator polynomial; performing a Chien search to determine a plurality of roots of the roughly-estimated error locator polynomial; and performing at least one check operation to selectively utilize a correction result of the error correction code as a decoding result of the error correction code.

A method of operation for a Reed-Solomon decoder includes receiving partial input data of symbols of a Reed-Solomon codeword; updating Reed-Solomon syndromes and error location polynomial coefficients based on the partial input data; maintaining the Reed-Solomon syndromes and the error location polynomial coefficients in a memory prior to starting activation of Reed-Solomon decoding; and inputting the Reed-Solomon syndromes and the error location polynomial coefficients to a first activation of Reed-Solomon decoding including calculating an initial error evaluator polynomial as a first error evaluator polynomial, performing error detection based on the first error evaluator polynomial to determine presence and location of errors in an input Reed-Solomon codeword, and updating the error location polynomial when errors are found in the input Reed-Solomon codeword. The error location polynomial coefficients in the memory are updated during each activation of Reed-Solomon decoding when at least one error is identified in the Reed-Solomon codeword.

A construction method for a (n,n(n1),n1) permutation group code based on coset partition is provided. The presented (n,n(n1),n1) permutation group code has an error-correcting capability of d1 and features a strong anti-interference capability for channel interferences comprising multi-frequency interferences and signal fading. As n is a prime, for a permutation code family with a minimum distance of n1 and a code set size of n(n1), the invention provides a method of calculating n1 orbit leader permutation codewords by O.sub.n={o.sub.1}.sub.=1.sup.n-1(mod n) and enumerating residual codewords of the code set by P.sub.n=C.sub.nO.sub.n={(l.sub.1).sup.n-1O.sub.n}={(r.sub.n).sup.n-1O.sub.n}. Besides, a generator of the code set thereof is provided. The (n,n(n1),n1) permutation group code of the invention is an algebraic-structured code, n1 codewords of the orbit leader array can be obtained simply by adder and (mod n) calculator rather than multiplication of positive integers. Composition operations of the cyclic subgroup C.sub.n acting on all permutations o.sub. of the orbit leader permutation array O.sub.n are replaced by well-defined cyclic shift composite operation functions (l.sub.1).sup.n-1 and (r.sub.n).sup.n-1 so that the action of the cyclic group acting on permutations is realized by a group of cyclic shift registers.

An apparatus for generating encoded data includes processing circuitry configured to encode data using a Mojette transform (MT) based on generating encoded representations of data blocks. Generating the encoded representations of data blocks includes reading data in the form of a data block formatted according to specified settings to comprise rows and columns, creating a set of projections, and outputting the created set of projections to enable storage of the data in the form of the set of projections. The apparatus then transmits the encoded data over a network to another device. Additionally, creating the set of projections includes applying the Mojette transform on the data block, and creating a first number of projections based on mapping each row of the data block to a corresponding projection, wherein the first number of projections carries the same information as a corresponding row.