MULTIFREQUENCY SIGNAL RECEIVER

摘要

PURPOSE:To make discrete Fourier conversion possible without a multistage shift rgister, by using a primary cyclic digital filter, where the filter coefficient is a positive number smaller than 1, in the multifrequency signal converter using discrete Fourier conversion. CONSTITUTION:When an input signal f(nt) is inputted to a terminal 1, cosnomegaT and sinnomegaT supplied from a generating circuit 7 are multiplied by multipliers 31 and 32 and are inputted to adders 41 and 42. Adders 41 and 42 constitute a primary cyclic digital filter together with multipliers 35 and 36 for multiplication of a filter coefficient alpha (alpha is a positive number smaller than 1) and one-period delay registers 51 and 52, and a real part Fc' and an imaginary part Fs' are outputted from adders 41 and 42. The Fc' and the Fs' are squared and are added by an adder 45.