An optical receiver may receive input signals carried by sub-carriers, and may apply test phases to each input signal. The extractionlocking device alternately secures an insert to the base and assists in extracting the insert from the base. A wear-compensating device is assigned to at least one of the clutch areas. In addition, the system may adapt its processing based on location to take into account locally expected siren formats. The first baseline wander corrector corrects a baseline variation by a feedforward control.