Device and associated method for calculating the direct or inverse fourier transform of the product of a complex symbol times a complex sinusoidal waveform

The invention relates to electronic calculating devices making it possible to calculate the direct or inverse Fourier transform of the product of a complex input symbol of size N times a complex sinusoidal waveform of period n, and their modes of operation. The invention applies, for example, to devices having a so-called "serial" or "pipelined" architecture. A device includes a processor able to calculate the direct or inverse Fourier transform of the product of a complex input symbol of size N times a complex sinusoidal waveform of period n. The calculation is performed on the basis of elementary processes of the butterfly type corresponding to several stages of a general butterfly-shaped calculation graph where n is an integer less than N. The processor includes a first elementary processor able to simultaneously perform the multiplication and the Fourier transform calculations relating to the first stage of the graph.