Quellsignal

Quellsignal, in German, denotes the source signal or excitation signal that enters a system and drives its response. It is the original waveform used to probe a process, test a device, or transmit information through a channel. In measurement and experimentation, the Quellsignal is chosen to reveal the system’s characteristics and behavior.

In signal processing and system identification, the Quellsignal is the input x(t) to a system, whose output y(t) is observed. For linear time-invariant models, the relation y(t) = h * x(t) allows estimation of the impulse response h or the transfer function H. The usefulness of the analysis depends on the properties of the Quellsignal, including bandwidth, determinism, repeatability, and signal-to-noise ratio.

Common types include deterministic signals (sine waves, chirps, ramps) and stochastic signals (white noise, colored noise). In practice, signals are generated with equipment such as arbitrary waveform generators and digital-to-analog converters, then prepared through scaling, windowing, or replay to suit testing needs.

Practical considerations encompass sampling rate, aliasing, dynamic range, phase alignment, and synchronization with measurement systems. A well-chosen Quellsignal enables stable identification, reliable deconvolution, and accurate calibration.

Applications span audio engineering, telecommunications, control systems, seismology, and radar. Examples include using a logarithmic sine sweep to measure frequency response or employing pseudo-random sequences for system identification and channel testing.

See also: source signal, excitation signal, input signal, system identification, impulse response.