DEVICE FOR EMBODYING A WINDOW ALGORITHM, ESPECIALLY CONCERNED WITH REDUCING THE NUMBER OF A MULTIPLY TO EFFECTIVELY DECREASE COMPLEXITY IN THE WINDOW ALGORITHM WHEN AN INPUT VALUE IS A COMPLEX NUMBER

摘要

PURPOSE: A device for embodying a window algorithm is provided to multiply coefficients each other, thereby suppressing an increase of a multiply generated by multiplications of complex numbers. CONSTITUTION: A constant counter(303) outputs a predetermined constant "s" to be used for renewing a window coefficient from an input sample. A coefficient calculator(302) multiplies an original window coefficient by the constant "s" outputted from the constant counter(303), and generates a new window coefficient. A coefficient storage(301) multiplies the new window coefficient outputted from the coefficient calculator(302) by a coefficient value stored in the coefficient storage(301), and stores a renewed coefficient value. An input sample renewer(304) multiplies the last window coefficient outputted from the coefficient storage(301) by the new window coefficient outputted from the coefficient calculator(302), and multiplies the last renewed coefficient by a sample of a complex number to renew the input sample.