The present invention provides a radio system and a method for relaying radio signals. The radio system and the method provide a calibration of transmit radio signals in which no dedicated calibration signal generator is required for calibrating the radio system. The radio system comprises at least one transmit path, a calibration unit at the least one link. A coupled transmit signal is extracted from the transmit paths and selectively forwarded as a feedback signal to a feedback signal demodulator. The feedback signal demodulator generates a base band feedback signal adapted for updating phase and amplitude changes applied a calibrated payload signal.