Method and device for multiplexing data signals

In a Code Division Multiple Access satellite communication system, a method of multiplexing data signals to be transmitted on a modulated transmission carrier to a plurality of terminal stations by phase-shift keying carrier modulation, said method comprising the steps of:

• prior to modulating the transmission carrier, individually encoding each binary signal into an individual symbol pertaining to a constellation of a finite number of symbols associated to the same number of distinct points so as to produce first and second bit streams, the first bit stream being in phase with an incoming signal and the second bit stream being in phase-quadrature with said incoming signal, and
• assigning to each of said two bit streams an individual signature by applying an individual spreading code to such bit stream thereby to produce two spread code to such bit stream thereby to produce two spread composite bit streams intended each to being applied to a modulator, the individual spreading codes being in quasi-orthogonal cross-correlation therebetween.