Over the air calibration and testing of beamforming-based multi-antenna devices in anechoic and non-anechoic enviornments

Embodiments provide a method for wirelessly calibrating/testing RF and digital components of a multi-antenna device under test. The method comprises the step of wirelessly transmitting a first signaling information between the device under test and a device tester, the first signaling information indicating a calibration request, wherein the first signaling information is transmitted by the device under test or the device tester. Further, the method comprises the step of estimating, in response to the first signaling information, channel transfer function matrices between active antenna ports/RF ports of the device under test and antenna ports of the device tester using reference signals wirelessly transmitted between the device tester and the device under test or vice versa. According to a first alternative, the method further comprises a step of wirelessly transmitting precoded reference signals between the device tester and the device under test using precoder matrices selected or determined based on the estimated channel transfer function matrices or the information derived therefrom. According to a second alternative, the method comprises a step of selecting or estimating equalizer matrices using the estimated channel transfer function matrices or the information derived therefrom.