Method and device for coding and transmission using a sub-code of a product code

Device for transmitting information representing a physical quantity and represented by first binary symbols, having:

• coding means comprising means of calculating second binary symbols, referred to as calculated binary symbols, from the information, the calculated binary symbols being provided in order to be disposed in a square table,
• means of transferring the said calculated binary symbols, comprising means of modulating the calculated binary symbols, and means of demodulating the modulated symbols into symbols referred to as received symbols,
• means of correcting the received symbols, thus providing corrected symbols, and
• means of decoding the information from the corrected symbols,
• characterised in that, the calculation means is adapted so that, for each calculated binary symbol, there exist at least three distinct diagonals in the table which contain this calculated binary symbol, and which still allow each one on its own to recalculate the calculated binary symbol,
• the demodulating means is adapted to implement a soft decision method, and
• the correcting means is adapted to implement a soft decision method, and
• the correcting means is adapted to implement an iterative correcting method with respect to each of the distinct diagonals.