High-speed, high-accuracy, apparatus for performing discrete Fourier and crete cosine transforms, suitable for signal processing applications. The apparatus includes a means for switching an input signal from a sample-and-hold circuit to a circuit which includes an integrator in cascade with an amplifier....http://www.google.fr/patents/US4068311?utm_source=gb-gplus-shareBrevet US4068311 - Discrete transform systems using permuter memories
Discrete transform systems using permuter memories
