Signal processing
That which you study for 4 years in order to design trippy music visualisers
March 19, 2015 — January 5, 2018
Signal processing is a discipline dedicated to the engineering end of stochastic process inference and prediction, especially linear time series.
There are various translation difficulties for statisticians; “Testing” = “Detection”, “Linear Filter” = “ARIMA model”, estimation of parameters is system identification, estimation of hidden states is filtering, and so on.
This is a general note to mention that the field exists. Most useful information is under sub-fields, e.g. machine listening, for some signal processing tricks for audio, or feedback systems, for some models particularly appropriate to systems that accept their own output as input, etc.
See also orthogonal basis decompositions. There are close connections to optimal control.
Anyway, I don’t need to explain that here; there are so many software engineers involved with it. The internet is full of interactive diagrammy textbooks to fill that niche.
But here are some notes on some nuggets of interest that I wasn’t sure where else to file.
1 Signal processing on graphs
Nothing to say here yet, but I feel I should raid the literature of the EPFL Signal processing lab 2 who make a specialty of it.
2 Stochastic decomposition
Model for decomposing harmonic sound into pure tones plus other stuff (aside: why not other periodic functions?) This is just some kind of parametric state or system inference, right?
3 Sampling
Signal sampling is the art of turning continuous signals into discrete ones and back again.
4 Resources
See also the slightly more specialised and overlapping list of filter design resources.
- Tom O’Haver has a free online textbook with extensive OCTAVE/MATLAB code, A Pragmatic Introduction to Signal Processing, skewed towards pure Fourier domain techniques.
- Textbook: Paolo Prandoni and Martin Vetterli, Signal Processing for Communications is available online. Vetterli is smart at unexpected and enlightening perspectives.
- Textbook: Antoniou has been generally recommended if you want to get hands-on ASAP. (Antoniou 2005)
- Textbook: Orfandis’ opus is free online. (Antoniou 2005)
- Course notes/textbook: Oppenheim and Verghese, Signals, Systems, and Inference is free online.
- Numerical tours of signal processing gives python, julia and matlab tours of signal processing. Better consumed through their github repo.