Variable node processing methods and devices for message-passing decoding of non-binary codes

A variable node processing unit implemented in a non-binary error correcting code decoder, the decoder being configured to determine and output an estimate of a codeword from a sequence received from a transmitter using messages exchanged between one or more variable node processing units and one or more check node processing units implemented in the decoder, wherein the variable node processing unit is configured to receive one check node message from a check node processing unit comprised in said decoder and intrinsic reliability metrics, and to generate one variable node message from auxiliary components extracted from a first auxiliary message or a second auxiliary message, said first auxiliary message being derived from said one check node message and intrinsic reliability metrics, said second auxiliary message being derived from at least some of said intrinsic reliability metrics, the intrinsic reliability metrics being derived from a received signal, an auxiliary component comprising an auxiliary symbol and an auxiliary reliability metrics associated with said auxiliary symbol, wherein the variable node processing unit comprises:

• a sorting and redundancy elimination unit configured to process iteratively the auxiliary components, one auxiliary component being processed at each iteration, and to determine components of the variable node message by iteratively sorting the auxiliary components according to a given order of the auxiliary reliability metrics and keeping a predefined number of auxiliary components comprising the auxiliary symbols that are the most reliable and all different from one another.