The invention relates to the establishment of a radio link using at least two spatial modes (in other words at least horizontal and vertical or right and left circular modes) by means of corresponding antennae or a line link using at least three conductors and the use of at least one transmission oscillator and no oscillator on the reception side, wherein the transmitter has amplitude and/or phase and/or frequency modulation and the at least two different polarized modes are received by means of at least two antennae and processed by one or more multipliers, mixers, phase comparators, frequency comparators, or power detectors.