DEVICE AND METHOD FOR FAST FOURIER TRANSFORM OPERATION, AND DEVICE AND METHOD FOR REVERSE FAST FOURIER TRANSFORM OPERATION

摘要

PROBLEM TO BE SOLVED: To provide a fast Fourier transform operation device which can shorten an arithmetic processing time by reducing the quantity of the arithmetic processing for complex multiplication.;SOLUTION: The fast Fourier transform operation device is equipped with a discrete Fourier transform means which has two inputs and performs fast Fourier transform with N inputs (N: power of 2) by using the discrete Fourier transform means. The discrete Fourier transform means is equipped with a sign inverting means which inverts the sign of an input value and outputs the resultant value, and finds a complex multiplication value as to a rotational factor corresponding to a unit vector on the real axis and a rotational factor corresponding to a unit vector on the imaginary axis among the complex products of complex input values and rotational factors by using the value of the real part of imaginary part of a complex input value and the sign- inverted value of the real part or imaginary part.;COPYRIGHT: (C)2004,JPO