A radio channel generator has a radio channel model predistorted on the basis of a predetermined chamber model. An emulator receives the weights of the radio channel model predistorted on the basis of the chamber model. A transmitter feeds a communication signal to the emulator. The emulator weights the communication signal with the radio channel model predistorted on the basis of the chamber model. The over-the-air antennas receive the weighted communication signal and transmit it to a device under test. The chamber model is based on a simulation or a measurement. The chamber model takes into account undesired interactions in the over-the-air chamber for cancelling them during the radio channel emulation.