Abstract:
The present invention relates to a method of decoding a one-point algebraic geometric code defined on an algebraic curve of type C(a,b) represented by an equation F(X,Y)=0 of degree b in X and of degree a in Y over Fq, comprising the following steps: —calculating extended error syndromes (σj(i)) associated with a received word (r); —determining the values of errors in each component (r(x, yp(x))) of the received word r, on the basis of the extended error syndromes calculated. Since the error value is determined for each component, it is not necessary to have recourse to an error locating step. The invention also relates to devices and apparatuses associated with the method.
Abstract:
Turbocoding methods use a first RSC coder operating on sequences of binary data a, and a second RSC coder operating on binary sequences a* each obtained from a by means of a predetermined permutation. These permutations are designed so that, for any sequence a represented by a polynomial divisible by the recursion polynomial, the associated sequence a* is also represented by a polynomial divisible by the recursion polynomial. These permutations are relatively simple to implement, and are applicable to all the data sequences a which have a length which is a multiple of the period of the recursion polynomial. In addition, once the transfer functions of the coders and the sequence length have been chosen, it is possible to select, amongst the corresponding permutations, the one which will probably offer the highest minimum distance of the code. Application to devices and apparatus implementing these methods.
Abstract translation:涡轮编码方法使用在二进制数据序列(U STYLE =“SINGLE”)a上操作的第一RSC编码器,以及从 a * SINGLE“> a通过预定的排列。 这些排列被设计成使得对于由可由递归多项式除除的多项式表示的任何序列 a,相关联的序列 a *也由多项式表示,该多项式可以被 递归多项式。 这些排列实现起来相对简单,并且适用于所有的数据序列 a,其长度是递归多项式周期的倍数。 另外,一旦选择了编码器的传递函数和序列长度,就可以在相应的排列中选择可能提供代码最大最小距离的排列。 应用于实现这些方法的设备和设备。
Abstract:
In order to decode a sequence α=(α1, . . . , αi, . . . , αn) where αi is the received electrical signal corresponding to a transmitted signal ai representing the ith binary element vi of a word v=(v1, . . . , vn) chosen in a code C of words satisfying v·hT=0, where h is a row n-tuplet on the set {0,1 }, whose number of 1 is denoted w, an item of extrinsic information ρext[A(i,h)]=P[ai=−1|A(i,h)]/P[ai=+1|A(i,h)] is determined on each of the elements vi covered by h, A(i,h) being the set of the received values αj covered by h, with the exception of αi, and P[ai|A(i,h)] being the probability that the ith signal transmitted was ai. This gives ρext[A(i,h)]=[S1(i)+S3(i)+ . . . ]/[1+S2(i)+S4(i)+ . . . ] where the numbers Sr(i) are calculated by applying the recurrence r - 1 ∑ i = 1 w z α i S r - 1 ( i ) - z α j S r - 1 ( j ) = S r ( j ) to the numbers S0(i) initialised to 1, with z=exp(−4 E/N), where E is the energy of the transmitted signals ai and N is the spectral power density of the noise on the transmission channel.
Abstract:
A method of transmitting information on a transmission channel associated with a first numerical alphabet that takes into account a matrix n×n with an orthogonal dominant H on a second numerical alphabet including at least three different non-null values, and a set of at least one sub-matrix of the matrix H, each sub-matrix of the set containing a number p greater than or equal to 2 rows of the matrix H. A sub-matrix from the set of sub-matrixes is selected along with a p-tuple of real numbers referred to as a “row of coefficients”, such that the matrix product of the row of coefficients and the selected sub-matrix supplies a sequence of numbers of the first alphabet, in order to represent the information to be transmitted. In addition to being orthogonal, matrix H is preferentially balanced.
Abstract:
The information transfer method uses: an alphabet Z2t={0, 1, 2, . . . 2t−1}, t≧3, in which additions and multiplications are carried out modulo 2t, and a lifted Hamming code whose generator polynomial is in Z2t. It includes: coding (302) of the information by a sequence of words of the said code, labelling (303), each letter of the alphabet Z2t labelling a letter of an alphabet A, for two adjacent symbols of A, one of the labels is the residue modulo 2t of the other incremented by 1, for each word of the said code, transmission (305) of signals, a physical quantity of which is proportional to the elements of A labelled by each of the symbols of the words of the said code.