A method and device for synchronizing a transmitter and a receiver with each other over a radio interface. A transmission signal is produced with a signal source in the transmitter and is transmitted via the radio interface. A corresponding receiver signal is received in the receiver from the radio interface and is evaluated using a receiver signal source signal from a signal source of the receiver adapted to the signal source of the transmitter. The same frequency modulation is applied to the receiver signal source signal, whereby the receiver signal received in the receiver is mixed with the receiver signal source signal to form a mixed signal and the mixed signal is analyzed with respect to frequency unbalance.