Generalized Short Time DFTのヒルベルト変換器への適用とその特性

Abstract

Instantaneous spectrum concept is a promising solution to effectively developing key devices for economical communication systems. An exact realization of the Hilbert transformer has been previously discussed with employing new concept of instantaneous spectrum defined by ST DFT. The Hilbert transformer used in SSB or RZ SSB modulator provides with indispensable function for eliminating one sideband from output signals to efficiently reduce occupied spectrum over radio channels. A new class of signal processing is introduced by generalized short time DFT, in which sub-channels are arbitrary adjusted on the objective frequency domain. Another implementation of the noble Hilbert transformer is discussed with employing this ST gDFT. Restricting the ST gDFT within causality, phase shifting error of implemented Hilbert transformer is examined to be so accurate as detecting no error by micro degree order. Simultaneously, its amplitude error is shown to be less than 0.01dB.