ARITHMETIC DEVICE FOR HIGH-SPEED FOURIER TRANSFORM

摘要

PURPOSE:To reduce the capacity of an interstage buffer memory, by performing butterfly operation of 2M points (MN) collectively when performing high-speed Fourier transform operation of 2N points. CONSTITUTION:For high-speed Fourier transform (FFT) operation of 2N points, buffers among the 1st-the (M)th, the (M+1)th-the (2M)th-, and the (KM+1)th- the (N)th arithmetic devices 100 are alternate buffers (where K is a maximum integer while KN/M) for holding data on 2M points, and alternate buffers between the (M)th and the (M+1)th, the (2M)th and the (2M+1)th-the (KM)th and the (M+1)th arithmetic devices are alternate buffers 603 and 604 for holding data on 2N points; and the buffers for holding the data on 2N are alternated every time butterfly operation of the 2N points ends, and the buffers for holding data on the 2M are alternated every time butterfly opration of the 2M points ends. Thus, the same high-speed arithmetic processing as conventional processing is performed with less memory capacity.