Abstract:
A method is provided for coding information representing a physical quantity and represented by first binary symbols, having an operation of calculating second binary symbols from the information, the second binary symbols being called calculated binary symbols and being provided in order to be disposed in a square table. For each calculated binary symbol, there exist at least three distinct diagonals in the table which contain this calculated binary symbol and which, deprived of this calculated binary symbol, still allow each one on its own to recalculate the calculated binary symbol. A coding device, a decoding method, a decoding device, a transmission method, and a transmission device are provided, as well as a camera, a facsimile machine, photographic apparatus, and a computer, implementing the invention.
Abstract:
A coding device that supplied code words, the symbols of which are capable of modulating a physical quantity on a transmission channel making use of symbols of a first alphabet. The decoding of these words uses symbols of a second alphabet containing the first alphabet, the cardinal of the second alphabet being strictly greater than that of the first alphabet and not being an integer power of the cardinal of the first alphabet. The coding device has an input of the “primary” symbols belonging to the first alphabet, a processor which determines redundant symbols capable of allowing decoding of the code words formed from primary symbols and redundant symbols, by a decoder working on the second alphabet, and solves a system of equations expressing the constraints to be met so that the redundant symbols are in the first alphabet, and an output of the symbols of the code words.
Abstract:
For each data element (symbol), a sequence of N points from a QAM constellation is transmitted. If the symbol period is T, then each point in the sequence may have a duration T/N. The sequence is determined by treating the constellation as a finite ring, and repeatedly multiplying the data point by a constant point.
Abstract:
A method of decoding a one-point algebraic geometric code of dimension k and length n, in which, in order to identify the position of the errors in a received word, the syndromes matrix S, of size (n−k)×(n−k), is defined, of which the elements Sij of each line i are calculated, for j between 1 and w(i), where the boundary w is a decreasing function, using the syndrome s of the received word. Matrices Su are constructed for the successive values of u starting with S1=S, and, for u>1, each matrix Su is obtained by performing on the matrix Su−1, column permutations where appropriate, then linear manipulations involving the line of index u. These steps are performed in such a manner as to find a matrix Sλ which has a line of index less than or equal to λ of which the elements are zero in the first w(λ) columns. The invention also relates to devices and apparatuses adapted to implement this method.
Abstract:
The present invention concerns a device (10) for the encoding of information symbols to transmit or to record, and for the correction of errors among the symbols received or read, according to codes defined over a Galois field Fq, where q is an integer greater than 2 and equal to a power of a prime number, and in which a set of elements of Fq are considered which are denoted yl(j), where j=1, . . . , R with 1≦R≦q−1 and l=0, . . . , p−1 with p>1. Said device (10) comprises a Reed-Solomon encoder (210), a Reed-Solomon decoder (220) and a unit (500) serving to calculate the inverse of a Vandermonde matrix as well as: registers “A” (420, 430, 440, 450) in which are stored, for the encoding, said information symbols, and, for the error correction, the symbols received or read after they have been corrected, registers “S” (280, 285, 290, 295) in which are stored, for the encoding, the symbols output from said Reed-Solomon encoder (210), and, for the error correction, the symbols entering said Reed-Solomon decoder (220), and registers “Y” (410, 411, 412, 413) in which said quantities yl(j) are stored.
Abstract:
Method and apparatus for decoding a one-point algebraic geometric code of dimension k and length n, in order to identify the position of the errors in a received word, the syndromes matrix S, of dimension (n−k)×(n−k) is defined, of which the elements Sij of each line i are calculated, for j between 1 and w(i), where the boundary w is a decreasing function, using the syndrome s of the received word, as well as the matrix S* obtained by “extending” the matrix S, that is to say by calculating the value of certain elements S*ij where j is greater than w(i). This method makes it possible in certain favorable cases to find the erroneous positions of the received word when the number of errors is greater than (n−k+1−g)/2, even if it is not possible to calculate all the elements of S* conventionally required by a two-stage algorithm to perform that correction.
Abstract translation:为了识别接收到的字中的错误的位置,对尺寸k和长度n的一点代数几何码进行解码的方法和装置,定义尺寸(nk)x(nk)的校正矩阵S, 对于i和w(i)之间的j,计算每行i的元素S ij ij,其中边界w是递减函数,使用综合征 s,以及通过“扩展”矩阵S而获得的矩阵S *,也就是说通过计算某些元素S * 其中j大于w的值 一世)。 该方法使得当误差数大于(n-k + 1-g)/ 2时,在某些有利的情况下可以发现接收字的错误位置,即使不可能计算出所有元素的全部元素 S *通常由两级算法执行该校正所要求的。