A method of operating a system (100, 200) for transmitting signals (si, S2, 202) from a transmitter (101, 206) to a receiver (104, 207), the method comprising the step of muting the transmitter (101, 206), adjusting a receiver transfer function of the receiver (104, 207) so that an output signal (sout) of the receiver (104, 207) is minimized, and setting a transmitter transfer function of the transmitter (101, 206) to be inverse to the adjusted receiver transfer function.