A testing device (3), especially a fading simulator incorporating antenna and circuit parameters, for testing a device under test (6), comprises a signal generating unit (4) and a fading simulation unit (5). The signal generating unit (4) generates a first number of signals according to a number of transmitting means (1) for a simulated transmission to the device under test (6). The fading simulation unit (5) outputs a second number of faded signals, which corresponds to a number of receiving means (2) of the device under test (6), to the device under test (6). It simulates the transmission channels between said transmitting means (1) and said receiving means (2) with the aid of an extended channel correlation matrix comprising a channel correlation matrix based on receive antenna characteristics of the device under test (6).