Patent ID: 8102137

Claim:
A method of detecting a useful signal (N) from a measurement signal (M) that is overlaid by at least one interference signal (Σ v ), which occurs with at least one known interference signal frequency (v), and the useful signal (N) being utilized in a control or regulating device, the method comprising the steps of: detecting the measurement signal (M); performing a Fourier transformation (F v (M)) of the measurement signal (M) only with reference to the known interference signal frequency (v) to detect an interference signal amplitude (A Σ ) and an interference signal phase (φ Σ ); detecting the interference signal (Σ v ) on a basis of the interference signal amplitude (A Σ ) and the interference signal phase (φ Σ ); and subtracting the interference signal (Σ v ) from the measurement signal (M) to detect the useful signal (N).