A digital communication system which applies channel coding and QAM modulation, where in QAM, at the transmitter, a number Q of bits is mapped to one QAM symbol, which is transmitted over the channel, at the receiver side, for each QAM symbol, a de-mapping is performed in order to obtain an L-value for each bit which corresponds to the QAM symbol, such that these L-values provide not only an estimation of the transmitted bits but also give information about their reliability.