Generation of radio frequency outputs
View Patent ↗Methods, systems, and apparatus can provide a plurality of RF outputs using a single digital to analog convertor (DAC) for digitally modulated data. In various examples, an intermediate frequency (IF) containing one or more digitally modulated channels is frequency down converted to meet the radio frequency (RF) specifications of a communication system.
1. A system, comprising:
a digital analog convertor (DAC) operable to synthesize a plurality of groups of one or more digitally modulated channels;
the DAC further operable to synthesize the plurality of groups of the one or more digitally modulated channels at frequencies within and greater than the RF passband of a communication system;
a frequency translator operable to generate a plurality of physical RF outputs by downconverting the one or more groups of the one or more digitally modulated channels synthesized at frequencies greater than the RF passband of the communication system to frequencies within the RF passband of the communication system,
wherein the frequency translator generates the plurality of physical outputs from the downconverted one or more groups of the one or more digitally modulated channels,
wherein each physical RF output is associated with one of the groups of the one or more digitally modulated channels.
2. The system of claim 1 , wherein one of the plurality of groups of the one or more digitally modulated channels are synthesized at frequencies within the RF passband of the communication system.
3. The system of claim 1 , wherein the frequency translator comprises one or more mixers and one or more filters operable to down convert and condition the one or more of the plurality of groups of the one or more digitally modulated channels synthesized at frequencies greater than the RF passband of the communication system.
4. The system of claim 1 , wherein the system is implemented by an edge quadrature amplitude modulation (EQAM) device.
5. The system of claim 1 , wherein the communication system is implemented by a wired network to communicate with one or more customer premise equipment (CPE) devices.
6. The system of claim 5 , wherein the wired network is a hybrid fiber-coax network.
7. A method, comprising:
receiving a first group of one or more digitally modulated channels;
synthesizing the first group of the one or more digitally modulated channels at frequencies within the RF passband of a communication system;
generating a RF physical output from the synthesized first group of the one or more digitally modulated channels; and
receiving one or more groups of the one or more digitally modulated channels different from the first group;
synthesizing the one or more groups of the digitally modulated channels different from the first group at frequencies greater than the RF passband of the communication system;
down converting the synthesized one or more groups of the digitally modulated channels different from the first group at frequencies greater than the RF passband to frequencies within the RF passband of a communication system; and
generating one or more RF physical outputs associated with the down converted one or more groups of the digitally modulated channels.
8. The method of claim 7 , wherein the digitally modulated channels are modulated using quadrature amplitude modulation (QAM).
9. The method of claim 7 , wherein the digitally modulated channels comprise one of video, data and voice information.
10. A system, comprising:
a digital analog convertor (DAC) operable to synthesize a plurality of groups of one or more digitally modulated channels;
the DAC further operable to synthesize the plurality of groups of one or more digitally modulated channels at frequencies greater than the RF passband of a communication system;
a frequency translator operable to generate a plurality of physical RF outputs by downconverting the one or more groups of the one or more digitally modulated channels synthesized at frequencies greater than the RF passband of the communication system to frequencies within the RF passband of the communication system,
wherein the frequency translator generates the plurality of physical outputs from the downconverted one or more groups of the one or more digitally modulated channels,
wherein each physical RF output is associated with one of the groups of the one or more digitally modulated channels.
11. The system of claim 10 , wherein the frequency translator comprises one or more mixers and one or more bandpass filters operable to down convert and condition one or more of the plurality of groups of one or more digitally modulated channels synthesized at frequencies greater than the RF passband of the communication system.
12. The system of claim 10 , wherein the communication system is implemented by a wireless network to communicate with one or more customer premise equipment (CPE) devices.
13. The system of claim 12 , wherein the wireless network comprises a cellular network.