Testing procedure and circuit for the determination of frequency distortions and group delay time distortion of a test object
AssigneeSiemens Aktiengesellschaft
InventorGerhard Blaass
Life of this patent
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Abstract
In testing to determine frequency distortions and group delay time distortions of a test object in a telecommunication link, a test pulse is introduced and its distortion caused by the test object is evaluated, which determination is specifically indicated in that the test pulse consist of a number of preselected oscillations, with respect to amplitude and phase of different frequencies, and that the return pulse is processed with the help of Fourier analysis and the individual frequency components are analyzed with respect to amplitude and phase relationship with respect to each other.
Claims19
Apparatus for determining frequency distortions and group delay time distortions of a transmission medium which carries a test pulse composed of a preselected number of oscillations of different frequencies having predetermined amplitudes and phase relationships, comprising:
- receiving means for receiving the test pulse;
- scanning means including an analog/digital converter connected to said receiving means and a scanner connected to said converter for causing said converter to convert the test pulse components into digital data;
- a memory connected to said analog/digital converter for storing the digital data;
- and
- analysis means connected to said memory for dividing the test pulse digital data components into the real and imaginary parts and determining the magnitude and phase of each component including comparison means for comparing the test magnitude and phase data with the original magnitude and phase data to determine damping and group delay time.
A process for determining frequency distortions and group delay time distortions of a communications link, as a test object, comprising the steps of:
- generating a test pulse having a preselected number of oscillations of different frequencies, predetermined amplitudes and phase relationships, in accordance with the expression ##EQU7## where n is the number of different oscillations, A.sub.n is a constant, and .phi..sub.n is the phase relationship of the different oscillations;
- applying the test pulse to the communications link;
- receiving the test pulse, including distortions thereof, from the communications link;
- performing a Fourier analysis of the received pulse;
- and
- analyzing the resultant Fourier components with respect to amplitude and phase relationships.
Dependencies are inferred from the claim text.