APPARATUS AND METHOD FOR CONVERTING AN ANALOG TIME DOMAIN SIGNAL INTO A DIGITAL FREQUENCY DOMAIN SIGNAL, AND APPARATUS AND METHOD FOR CONVERTING AN ANALOG TIME DOMAIN SIGNAL INTO A DIGITAL TIME DOMAIN SIGNAL

摘要

An apparatus (100; 200) for converting an analog time domain signal into a digital frequency domain signal is described, the apparatus comprising: a first analog-to-digital- converter (110) adapted to convert the analog time domain (v(t)) signal into a first digital time domain signal; a second analog-to-digital-converter (130) identical in construction to the first analog-to-digital-converter (110), wherein the second analog-to-digital-converter is adapted to convert the analog time domain signal (v(t)) into a second digital time domain signal; a first transformation unit (120) adapted to transform the first digital time domain signal into a first digital frequency domain signal (V1), a second transformation unit (140) adapted to transform the second digital time domain signal into a second frequency domain signal (V2); a frequency compensation unit (150) adapted to modify the second frequency signal so as to reduce a difference between a wanted signal component of the second frequency value and a wanted signal component of the first frequency value caused at least partially by a difference between frequency responses of the first and second analog-to- digital converter; a comparison unit (160) adapted to determine for a same frequency bin (k) a corresponding first energy value associated to a corresponding frequency value (V1(k)) of the first digital frequency domain signal (V1) and a corresponding second energy value associated to a frequency value (V2(k)) of the second digital frequency domain signal (V2), and to determine a minimum energy value thereof; and a selection unit (170) adapted to select for a same frequency bin (k) of the digital frequency domain signal (V) of the apparatus the digital frequency domain signal associated to the minimum energy value.