Discrete Fourier transform
fft(x) is the discrete
Fourier transform (DFT) of the Galois vector
x is in the Galois field GF(2m),
the length of
x must be 2m-1.
m = 4; n = 2^m-1; x = gf(randi([0 2^m-1],n,1),m); % Random vector y = fft(x); % Transform of x z = ifft(y); % Inverse transform of y ck = isequal(z,x) % Check that ifft(fft(x)) recovers x.
The output is
ck = 1
The Galois field over which this function works must have 256
or fewer elements. In other words,
x must be in
the Galois field GF(2m), where m is an
integer between 1 and 8.