A fast Fourier transform circuit formed on a single chip, including a fast multiplier-accumulator circuit which, in the preferred embodiment, employs a modified form of Booth's algorithm, an adder circuit, a read-only memory for storing FFT twiddle factors, and a random access memory for holding a set...http://www.google.fr/patents/US4547862?utm_source=gb-gplus-shareBrevet US4547862 - Monolithic fast fourier transform circuit
