Analog reconstruction of a digital signal
AssigneeNorthrop Grumman Corporation
InventorsCyrus Asafandiar Dhalla, Michael Steven Muñoz
Life of this patent
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Abstract
A system and method is provided for efficient analog reconstruction of a digital signal to an intermediate frequency (IF). The digital signal can be a complex baseband digital signal that is sourced from a near perfect reconstruction filterbank (NPRFB). The output of the NPRFB, after some manipulation in the digital domain, is converted to the analog domain at IF. The IF analog signal can then be modulated with a high frequency RF signal or further mixed with a RF transmission frequency signal for RF transmission.
Claims25
A system for analog reconstruction of a digital signal, the system comprising:
- an upsampling component that upsamples a digital signal by an upsampling factor to provide a plurality of spectral images being integer multiples of the digital signal at the Nyquist frequency divided by the upsampling factor, one of the plurality of spectral images being centered at an intermediate frequency (IF);
- a filter that filters out the spectral image centered at the IF;
- and
- a digital-to-analog converter (DAC) that converts the spectral image centered at the IF to an IF analog signal.
A system for converting a digital signal to an analog intermediate frequency, the system comprising:
- means for upsampling a wideband digital signal by an upsampling factor to provide a plurality of spectral images being integer multiples of the wideband digital signal at the Nyquist frequency divided by the upsampling factor, one of the plurality of spectral images being centered at an intermediate frequency (IF);
- means for filtering the spectral image centered at the IF;
- and
- means for converting the spectral image centered at the IF to an IF analog signal.
A method for analog reconstruction of digital signal to an intermediate frequency signal, the method comprising:
- providing an oversampled wideband digital signal;
- upsampling the oversampled wideband digital signal to provide a plurality of spectral images of the wideband digital signal separated by transition bands, one of the spectral images being centered at an intermediate frequency (IF);
- filtering the spectral image centered at the IF;
- and
- converting the spectral image centered at the IF to an IF analog signal.
A system for analog reconstruction of a digital signal, the system comprising:
- an upsampling component that upsamples a complex wideband digital signal by an upsampling factor to provide a plurality of spectral images of the digital signal;
- a real filter that the spectral image centered at baseband frequency;
- a multiplier mixed with the spectral image centered at baseband frequency to shift the spectral image to be centered at an intermediate frequency (IF), the multiplier being exp (j*2 π*f*t) where f is the IF and t is the time interval of the input signal to the multiplier;
- and
- a digital-to-analog converter (DAC) that converts the spectral image centered at the IF to an IF analog signal.
Dependencies are inferred from the claim text.