This is an animated slide deck providing a tour of digital signal processing topics relevant to implementation of software-defined radios, focusing on building visual/geometric intuition for signals.
Topics covered:
- Complex (IQ) and analytic signals.
- Filtering (FIR and IIR).
- Frequency shifting.
- Sampling rates and the Nyquist limit.
- The discrete Fourier transform (DFT) and fast Fourier transform (FFT).
- Digital modulation (OOK, PSK, QPSK, QAM).
I originally wrote down the idea for this presentation as follows:
sdr tutorial idea:
starting from interactive slide deck w/ live spiral-graph display
transform it in multiple ways
a fft corresponds to successive amounts of untwist + sum (does it?)
Use the MathBox WebGL framework
That sat around for a while until Balint Seeber organized a meetup group for SDR local to me, in November 2014, and I saw an excuse to do this thing — and here it is, exactly as originally conceived.
Here's the recording of that meetup with me giving this presentation. Note that this version does not include the material on digital modulations.
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