process for the implementation of the multi-level digital modulation signals by a computer numerical

摘要

A process for actuation of multi-level digital modulation and in particular QAM modulation by using a single microprocessor (DSP) is described. The process calls for synchronism of all the frequencies in play and comprises an oversampling of the symbols of the 'in phase' and 'in quadrature' channels and appropriate digital filtration thereof. A digital carrier is QAM modulated simply by selecting in string the symbols belonging to said digitally filtered channels taken with their true of negated value. Said symbols are then sent to a digital/analog converter (DAC) followed by a reconstruction filter (FRIC) to obtain the corresponding QAM modulated analog carrier. IMAGE