Over-the air test

1. A method of communicating wirelessly with an electronic device under test surrounded by antenna elements, the communication being performed through a simulated radio channel of an emulator, the method comprising:

transmitting noise wirelessly at a total noise power from at least two antenna elements to a device under test,

the total noise power being based on a total signal power received by the emulator, a gain of at least one antenna-specific channel between the emulator and antenna elements, and a desired signal-to-noise ratio;

forming a complex Gaussian noise corresponding to a desired noise power distribution of the total noise power; and

feeding the Gaussian noise to the at least two antenna elements.

2. The method of claim 1 , further comprising:

weighting the total signal power with the gain of the at least one antenna-specific channel in order to form a total antenna power;

dividing the total antenna power by the desired value of a signal-to-noise ratio to form the total noise power; and

providing the at least two antenna elements with noise of a desired noise power distribution for transmission over a frequency, the desired noise power distribution having the total noise power.

3. The method of claim 1 , further comprising transmitting, by the at least two antenna elements, the noise whose noise power is the total noise power divided by a number of the antenna elements transmitting the noise.

4. The method of claim 1 , further comprising forming the total noise power in a predetermined time window on the basis of time averages of the total signal power and the gain of the at least one antenna-specific channel in the predetermined time window.

5. The method of claim 1 , further comprising transmitting the noise uniformly from all directions towards the DUT.

6. A testing system for communicating wirelessly with an electronic device under test surrounded by a plurality of antenna elements, at least one of which is connected to an emulator, which is configured to form a simulated radio channel for the communication, the testing system comprising:

a noise source coupled to at least two antenna elements,

the noise source forming a total noise power on the basis of a total signal power received by the emulator, a gain of at least one antenna-specific channel between the emulator and the antenna elements, and a desired signal-to-noise ratio,

the noise source transmitting noise wirelessly at the total noise power from the at least two antenna elements to the device under test.

7. The testing system of claim 6 , wherein the noise source weights the total signal power with the gain of the at least one antenna-specific channel in order to form a total antenna power,

the noise source dividing the total antenna power by the desired value of a signal-to-noise ratio to form the total noise power,

the noise source providing the at least two antenna elements with a desired noise power distribution for transmission over a frequency, the desired noise power distribution having the total noise power.

8. The testing system of claim 6 , wherein the noise source transmits, through the at least two antenna elements, a noise power having the total noise power divided by a number of antenna elements transmitting the noise.

9. The testing system of claim 6 , wherein the noise source forms the total noise power in a predetermined time window on the basis of time averages of the total signal power and the gain of the at least one antenna-specific channel in the predetermined time window.

10. The testing system of claim 6 , wherein the noise source generates complex Gaussian noise corresponding to the desired noise power distribution of the total noise power, the noise source feeding the Gaussian noise to the at least two antenna elements.

11. The testing system of claim 6 , wherein the testing system transmits the noise uniformly from all directions towards the DUT.