Systems and methods for selecting digital content channels using low noise block converters including digital channelizer switches
View Patent ↗Systems and methods in accordance with embodiments of the invention include converting satellite signals to an intermediate frequency signal for content decoding, and selecting modulated digital data within the satellite signals for content decoding using digital signal processing. One embodiment includes a system configured to select at least one content channel from an input signal including a plurality of content channels modulated onto a carrier, the system including: a digital channelizer switch including: a high speed analog to digital converter configured to digitize an intermediate frequency signal; a digital channelizer configured to digitally tune a content channel from the digitized intermediate frequency signal; and a high speed digital to analog converter configured to generate an analog output signal using the content channel digitally tuned from the digitized intermediate frequency signal by the digital channelizer.
1. A system for selecting content channels modulated onto a carrier, the system comprising:
a mixer configured to convert the content channels to an intermediate frequency signal;
a high-speed analog-to-digital converter configured to digitize the intermediate frequency signal;
a digital channelizer configured to digitally select content channels from the digitized intermediate frequency signal, where the digital channelizer comprises:
at least one poly-phase filter,
an N-points Fast Fourier Transform,
a plurality of selectors, wherein each selector is operable to select, among a plurality of outputs of the N-points Fast Fourier Transform, an output corresponding to a particular content channel,
a plurality of variable gain elements, wherein each variable gain element is operable to apply particular gain to an output of a corresponding one of the plurality of selectors, and
a gain control element that is operable to apply common gain control to all of the content channels; and
a high-speed digital-to-analog converter configured to generate an analog output signal using the digitally selected content channels.
2. The system of claim 1 , wherein the mixer comprises a local oscillator.
3. The system of claim 1 , wherein a frequency of the carrier signal is in a range from 10.7 GHz to 12.75 GHz.
4. The system of claim 1 , wherein a frequency of the intermediate frequency signal is in a range from 0.2 GHz to 2.25 GHz.
5. The system of claim 1 , wherein a frequency of the analog output signal is in a range from 950 MHz to 2150 MHz.
6. The system of claim 1 , wherein a frequency of the analog output signal is in a range from 950 MHz to 1450 MHz.
7. The system of claim 1 , wherein the high-speed analog-to-digital converter is configured to sample the intermediate frequency signal at a frequency at least twice a highest frequency of the intermediate frequency signal.
8. A method for selecting content channels modulated in different frequency bands on a carrier signal, the method comprising:
down converting the content channels to an intermediate frequency signal;
digitizing the intermediate frequency signal using a high-speed analog-to-digital converter;
digitally selecting content channels from the digitized intermediate frequency signals using a digital channelizer that comprises:
at least one poly-phase filter,
an N-points Fast Fourier Transform,
a plurality of selectors,
a plurality of variable gain elements, and
a gain control element,
wherein selecting the content channels via the digital channelizer comprises:
selecting, via the plurality of selectors, among a plurality of outputs of the N-points Fast Fourier Transform, an output corresponding to a particular content channel;
applying via each one of the plurality of variable gain elements a particular gain to an output of a corresponding one of the plurality of selectors; and
applying via the gain control element common gain control to all of the content channels;
combining the selected content channels; and
generating an analog output signal containing the combined selected content channels.