SDR Theory
From Hamspirit wiki
Useful links
- I/Q Data for Dummies A simple explaination of IQ signals.
- interactive complex FFT example
- The Scientist and Engineer's Guide to Digital Signal Processing
- http://www.earlevel.com/main/2010/12/11/a-closer-look-at-upsampling-filters/
Polyphase discrete Fourier transform (Polyphase DFT)
AKA: "weighted overlap-add", "Window-presum FFT"
This technique is used to create a better spectrogram or panoramic display. It suffers less from the spectral-leakage that normal DFT has.
