The invention related to a method and to a test device for analyzing a device communicating via a radio link. Said device comprises a plurality of antennas for communicating, together comprising an antenna arrangement. The device under test is first disposed in a first position relative to a radio field. A value of at least one piece of channel state information describing a quality of the antenna arrangement obtained via the return channel is determined in said relative position. A change in the relative position of the device under test relative to the radio field is subsequently performed. A second value of the at least on piece of channel state information is determined in said changed, new relative position.