Abstract: A scheme for coding digital source data, implementing, in parallel, at least two elementary coding steps each taking into account all of the source data, and including a permutation step modifying a sequence of consideration of the source data between the elementary coding steps. In one example, the source data is organized in sequences of non-binary symbols, each non-binary symbol including n binary source elements, n being greater than or equal to 2. The example permutation step includes reversibly modifying contents of at least some of the non-binary symbols, delivering modified non-binary symbols, and permutating the sequence of the source or modified non-binary symbols.

Abstract: Equalizing and decoding apparatus including a module which comprises an equalizer and a weighted output decoder, the apparatus being characterized in that it comprises a plurality of modules of said type in series, in which each equalizer has at least one transversal filter for reducing noise power and in which each module of rank greater than 1 also receives a stream of channel samples that has been delayed by a quantity equal to the processing time of the preceding modules.

Abstract: The invention relates to a device for the reception of signals formed by a series of digital symbols corresponding to the convolutive encoding of items of source digital data comprising p cascade-connected detection and decoding modules M.sub.1 to M.sub.p, p being greater than or equal to 2, each of said modules M.sub.i including: (a) inter-symbol interference correction means supplied by a symbol input R.sub.i and delivering estimated symbols A.sub.i,1 with weighted values, (b) means for the decoding of said estimated symbols A.sub.i,1, performing operations symmetrical to said convolutive encoding and delivering decoded symbols A.sub.i,2 with weighted values, and (c) means for the computation of an item of correction information Z.sub.i+1 from said estimated symbol A.sub.i,1 and said decoded symbol A.sub.i,2, (d) said means for the correction of each of said modules M.sub.i, except for the first module M.sub.1, taking account of at least one item of correction information Z.sub.

Abstract: The transmitted bits are coded according to the product of at least two systematic block codes. An iterative decoding is applied in order to determine, at each code word search step, a data matrix and a decision matrix which are used for the following step. The new decision matrix is determined at each step by decoding the rows or the columns of the input matrix, and the new data matrix is determined by taking account of correction terms which increase the reliability of the decoding at each iteration. The method is especially suited for use with high-efficiency block codes.