A radio system for relaying radio signals, the radio system comprising: - at least one transmit path (70-1, 70-2,..., 70-N) adapted to forward a payload signal as a transmit signal (75-1, 75-2,..., 75-N), - the at least one transmit path (70-1, 70-2,..., 70-N) comprising an amplifier (30-1, 30-2,..., 30-N) for amplifying the transmit signal (75-1, 75-2,..., 75-N), a duplex filter (40-1, 40-2,..., 40-N) for separating the transmit paths (70-1, 70-2,..., 70-N) from receive paths (Rx-1, Rx-2,..., Rx-N), a first coupler (50a-1, 50a-2,..., 50a-N), arranged before the duplex filter (40-1, 40-2,..., 40-N) in a transmit direction, adapted to extract a first coupled transmit signal (90a-1, 90a-2,..., 90a-N) from the transmit signal (75-1, 75-2,..., 75-N), a second coupler (50b-1, 50b-2,..., 50b-N), connected between the duplex filter (40-1, 40-2,... 40-N) and an antenna element (60-1, 60-2,..., 60-N), adapted to extract a second coupled transmit signal (90b-1, 90b-2,..., 90b-N), and at least one switch (S-1, S-2,..., S-N) adapted to select one between the first coupled transmit signal (90a-1, 90a-2,..., 90aN) and the second coupled transmit signal (90b-1, 90b-2,... 90b-N) individually for each one of the transmit paths (70-1, 70-2,..., 70-N), - a digital predistortion unit adapted to apply a digital predistortion to the payload signal for linearising a transfer characteristic of the radio system, - a calibration unit adapted to apply phase and amplitude changes (210-1, 210-2,..., 210-N) to the at least one transmit path (70-1, 70-2,..., 70-N), - a feedback path commonly used by the digital predistortion unit and the calibration unit for feeding back a selected one of the coupled transmit signals (90a-1, 90a-2,..., 90a-N, 90b-1, 90b-2,..., 90b-N) as a feedback signal, wherein at least one of: the phase and amplitude changes (210-1, 210-2,..., 210-N) and the digital predistortion (310-1, 310-2,..., 310-N) is adaptable using the feedback signal, wherein the radio system comprises a further switch for further selecting one of the coupled transmit signals from the individually selected ones of the first coupled transmit signals (90a-1, 90a-2,..., 90a-N) or the second coupled transmit signals (90b-1, 90b-2,..., 90b-N) and for forwarding the further selected one of the coupled transmit signals as the feedback signal, wherein, if a first coupled transmit signal (90a-1, 90a-2,..., 90a-N) has been further selected, it is used for updating of the digital predistortions (310-1, 310-2,..., 310-N) and, if a second coupled transmit signal (90b-1, 90b-2,..., 90b-N) has been further selected, it is used for calibrating the phase and amplitude changes (210-1, 210-2,...,210-N). - at least one transmit path (70-1, 70-2,..., 70-N) adapted to forward a payload signal as a transmit signal (75-1, 75-2,..., 75-N), - the at least one transmit path (70-1, 70-2,..., 70-N) comprising an amplifier (30-1, 30-2,..., 30-N) for amplifying the transmit signal (75-1, 75-2,..., 75-N), a duplex filter (40-1, 40-2,..., 40-N) for separating the transmit paths (70-1, 70-2,..., 70-N) from receive paths (Rx-1, Rx-2,..., Rx-N), a first coupler (50a-1, 50a-2,..., 50a-N), arranged before the duplex filter (40-1, 40-2,..., 40-N) in a transmit direction, adapted to extract a first coupled transmit signal (90a-1, 90a-2,..., 90a-N) from the transmit signal (75-1, 75-2,..., 75-N), a second coupler (50b-1, 50b-2,..., 50b-N), connected between the duplex filter (40-1, 40-2,... 40-N) and an antenna element (60-1, 60-2,..., 60-N), adapted to extract a second coupled transmit signal (90b-1, 90b-2,..., 90b-N), and at least one switch (S-1, S-2,..., S-N) adapted to select one between the first coupled transmit signal (90a-1, 90a-2,..., 90aN) and the second coupled transmit signal (90b-1, 90b-2,... 90b-N) individually for each one of the transmit paths (70-1, 70-2,..., 70-N), - a digital predistortion unit adapted to apply a digital predistortion to the payload signal for linearising a transfer characteristic of the radio system, - a calibration unit adapted to apply phase and amplitude changes (210-1, 210-2,..., 210-N) to the at least one transmit path (70-1, 70-2,..., 70-N), - a feedback path commonly used by the digital predistortion unit and the calibration unit for feeding back a selected one of the coupled transmit signals (90a-1, 90a-2,..., 90a-N, 90b-1, 90b-2,..., 90b-N) as a feedback signal,