is an element of order
in
, where
is a Fermat prime for
. Hence it can be used to define a fast Fourier transform (FFT) of as many as
symbols in
. Since
is a root of unity of order
in
, this transform requires fewer muitiplications than the conventional FFT algorithm. Moreover, as Justesen points out [1], such an FFT can be used to decode certain Reed-Solomon codes. An example of such a transform decoder for the case
, where
is in
, is given.