Patent ID: 9007251
Filing Date: 2015-04-14
Classification: G01R,H03M

Abstract:
1. An apparatus for converting an analog time domain signal into a digital frequency domain signal, the apparatus comprising: a first analog-to-digital-converter adapted to receive the analog time domain signal and to convert the analog time domain signal into a first digital time domain signal according to a first frequency response; a second analog-to-digital-converter identical in construction to the first analog-to-digital-converter, wherein the second analog-to-digital-converter is adapted to receive the analog time domain signal and to convert the analog time domain signal into a second digital time domain signal according to a second frequency response, the second frequency response differing from the first frequency response; a first transformation unit adapted to transform the first digital time domain signal into a first digital frequency domain signal, wherein the first digital frequency domain signal comprises for a frequency bin of the first digital frequency domain signal a corresponding first frequency value, wherein the first frequency value comprises a first wanted signal component, a first spurious signal component and/or a first noise component, the first spurious signal component and/or the first noise component at least partially being caused by the first analog-to-digital-converter; a second transformation unit adapted to transform the second digital time domain signal into a second frequency domain signal, wherein the second digital frequency domain signal comprises for a same frequency bin of the second digital frequency domain signal a corresponding second frequency value, wherein the second frequency value comprises a second wanted signal component, a second spurious signal component and/or a second noise component, wherein the second spurious signal component and/or the second noise component are at least partially caused by the second analog-to-digital-converter, and wherein the second spurious signal component differs from the first spurious signal component and/or the second noise component differs from the first noise component; a frequency compensation unit adapted to modify the second frequency signal so as to reduce a difference between the second wanted signal component of the second frequency value and the first wanted signal component of the first frequency value caused at least partially by the difference between the second frequency response and the first frequency response; a comparison unit adapted to determine for the same frequency bin a corresponding first energy value associated to the first frequency value and a corresponding second energy value associated to the second frequency value, to compare the first energy value and the second energy value, and to determine a minimum energy value thereof; and a selection unit adapted to select for a same bin of the digital frequency domain signal of the apparatus the corresponding first frequency value in case the corresponding first energy value is the minimum energy value, or the corresponding second frequency value in case the corresponding second energy value is the minimum energy value.