METHOD AND APPARATUS FOR PROCESSING A DIGITAL SIGNAL FOR ANALOG TRANSMISSION

In a digital preprocessing system for processing a digital signal for analog transmission, the digital signal is up-sampled to produce a digital up-sampled signal having signal components in a plurality of Nyquist bands including a first Nyquist band and a plurality of super-Nyquist bands at higher frequencies than the first Nyquist band, wherein the first Nyquist band includes a baseband signal component and a plurality of aliased signal components. Thereafter, one of the plurality of signal components in the first Nyquist band is selected from the digital up-sampled signal. Finally, the selected one of the plurality of signal components is output at a frequency that will cause a digital to analog converter to output an aliased signal component in a super-Nyquist band nearer an anticipated peak amplitude of a filtering characteristic of the digital to analog converter than an aliased signal component in the super-Nyquist band that would be output by the digital to analog converter processing the baseband signal component.