Multichannel signal modulator for use in broadcast satellite applications

A multichannel signal modulator for use in the digital generation of a unitary multichannel signal at a selected bandwidth from a plurality of source signals, said multichannel signal modulator being a device comprising:

• a plurality of signal inputs each comprising a device connection for reception of a separate source signal from a signal source;
• a signal assembly system, comprising:
• modulation means, namely a plurality of modulator circuits corresponding to the plurality of source signals and each operatively connected to one of the plurality of signal inputs for the modulation of the corresponding source signal, wherein following modulation by the plurality of modulator circuits the plurality of source signals is a plurality of modulated signals;
• source upsampling means, namely a plurality of source upsamplers corresponding and operatively connected to each of the plurality of modulator circuits and each capable of upsampling the related modulated signal to an upsampled signal at at least one selectable sample rate shared with each of the other of the plurality of source upsamplers, whereby in operation upon selection of a selected common sample rate from the available selectable sample rates selected to allow representation of each of the plurality of source signals in the ultimately completed unitary multichannel signal at the selected bandwidth, each source upsampler will yield an upsampled signal at the selected common sample rate;
• frequency mixing means, namely a frequency mixer operatively connected to the source upsampling means to receive and combine the plurality of upsampled signals into a unitary signal;
• and
• final upsampling means, namely a final upsampler operatively connected to the frequency mixer for the upsampling of the unitary signal into a unitary multichannel signal at the selected bandwidth;
• and
• a signal output for output of said unitary multichannel signal from the signal assembly system at the selected bandwidth;
• wherein in operation the signal assembly system will:
• modulate each source signal received via its corresponding modulator circuit into a modulated signal;
• select a selected common sample rate for use by the source upsamplers from the at least one available selectable sample rate;
• upsample each modulated signal at the selected common sample rate into an upsampled signal, via the source upsampler corresponding to the corresponding modulator circuit;
• using the frequency mixer, mix the plurality of upsampled signals into a unitary signal;
• and
• format the unitary signal into the desired final unitary multichannel signal at the selected bandwidth using the final upsampler for output via the signal output, wherein the final unitary multichannel signal contains a representation of all of the source signals by virtue of the selection and application of the appropriate selected common sample rate.