Original Source: https://ccrma.stanford.edu/~jos/ReviewFourier/Example_FFT_Convolution.html
Matlab - GNU/Octave functions for Fast convolution and deconvolution using Fast Fourier Transform (FFT).
Run the example.m script to see an example of the usage of the functions by filtering a white noise signal with an impulse response of a bandpass filter through FFT Convolution, and then by using the FFT deconvolution, extract the original IR using the original and filtered signals.
The fftconv.m takes two parameters: an x row vector of a signal to be processed, and an h row vector of an Impulse Response signal, and returns a y vector with the fast convolution of the two signals.
y = fftconv(x,h)
x and h must be row vectors
x = Data
h = Impulse Response
y = Output
The fftdec.m takes two parameters: a row vector out of an affected/processed signal, and a row vector in: the original signal before being affected/processed, and returns a y vector with the Impulse Response of the system or Device Under Test.
h = fftdec(out,in)
IN and OUT must be row vectors
out = System Output, filtered/affected signal.
in = System Input, original signal.
h = Impulse response -> h(n)