TimesToCome Mobile

iOS apps and tips, tricks and tools for smart phones

Using the FFT to decipher a signal




I recently began to learn about signal processing. There’s a lot of theory out there but little on the basics and much of what should be obvious isn’t. I ended up writing a test program I could play with and decipher. By adjusting the signal, frequency of samples, window size &c you’ll see how it all fits together.

TestFFT

Download the full project

Signal Processing Resources:
Texts (free, online)
Intro to Digital Filters
Mathematics of the Discrete Fourier Transform
Spectral Signal Processing
The Scientists and Engineer’s Guild to Digital Signal Processing
Signal Processing for Communications
Complex to Real, Tutorials on Digital Communications Engineering

Math
The Nyquist Sampling Theorem
An Interactive Guide to the Fourier Transform

Coding
Mike Ash: Obtaining and Interpreting Audio Data
Invasive Code: A Quasi Real Time Video Processing on iOS

Papers
Arxiv: DSP

Online Classes
Coursera DSP
Coursera Fundamentals EE