Centre National De La Recherche Scientifique

Université De Bretagne Sud

Oussama Abassi

Emmanuel Boutillon

Laura Conde-Canencia

A method is proposed for managing a parity-check node calculation unit of an error-correcting code decoder having a representation as a bipartite graph comprising at least one parity-check node, the parity-check node being configured to receive first and second input messages, and to produce an output message, the elements of the input and output messages of the parity-check node comprising a symbol and a measure of reliability associated with the symbol, the first and second input messages containing lists of elements ordered by their measure of reliability. The method comprises: initializing a plurality of nFIFO memories with elements calculated from combinations of elements of the first and second input messages, and iteratively determining the values of the output message.

Decoding of non-binary LDPC codes

The invention concerns a method for transmitting symbols of non binary error correcting code words via a transmission channel. The method comprises a first modulation associating each code word symbol of p bits with a sequence of at least 2p chips from 2p possible sequences, a second modulation to modulate the phase or amplitude of a carrier signal with the sequences associated with the code words, and a step of transmitting the modulated carrier signal via said transmission channel. According to the invention, the first modulation is a spread spectrum modulation of the cyclic code shift keying type using a basic pseudo-random sequence of at least 2p chips, the possible 2p sequences being obtained by a circular shift of the basic pseudo-random sequence and a cyclic prefix is inserted into each symbol to be transmitted.

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Lorient, France

Oussama Abassi