A DIGITAL MODULATOR AND A METHOD FOR GENERATING A COMPLEX CARRIER MODULATED BY A DIGITAL SIGNAL

摘要

A digital modulator for generating a complex carrier modulated by a digital signal comprisings a source (202) of digital signal occurring at a given sample rate an upsampler (800) responsive to said digital signal* having an output providing samples at a sample rate higher than said given sample rate; a complex modulator (802) having a signal input coupled to the output of the upsampler, and having a carrier input; a source (804) of a repeating sequence of S complex values, with respective complex values occurring at said higher sample rate, applied to said carrier input; wherein the complex values of the sequence are selected to condition the modulator to provide a complex modulation centered about a pseudo-carrier, which pseudo-carrier has an impage corresponding to a desired frequency.