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Altera_Forum
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11 years ago

Inphase (I) and Quadrature (Q) components of signals

Hi All, How to calculate the Inphase (I) and Quadrature (Q) components of signals, such as RF signals? I would like to shift the RF signals to a specific baseband frequency and then derive the ...
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Altera_Forum
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11 years ago

Hi Dave,

I'm a bit confused with the Eq 37 (from your FPGA-DSP document) and the NCO megaCore function?

The fo in Eq 37 is a normalised frequency, the center frequency divided by the sampling frequency. Does that mean NCO should generate the cosine and sinusoid components with frequency of fo not the centre frequency? For example, the signal's centre frequency is 2.5MHz and the sampling frequency is 80MHz. So the normalised frequency fo = 2.5/80 = 0.0313. So in the NCO, the "Desired output frequnecy" shoud be set to 0.0313 not 2.5 MHz. Is it correct?

Many Thanks,

Lee