A detector for zero crossings and a counter which is connected to it are used to determine the time intervals between the zero crossings of the received signal or of an intermediate-frequency signal which is produced from the received signal, and for detection of the digital signal data. In this case, a sequence of determined zero crossing intervals can be stored in digital form in a shift register chain, and can be compared in a classification device with previously stored interval sequences. Furthermore, a frequency offset can be determined by averaging the zero crossing intervals and can be compensated for by suitable selection or modification of the previously stored interval sequences, in which case the latter can also be used during the synchronization phase. The synchronization process may, furthermore, be assisted by payload data identification.