Over the air testing for massive MIMO arrays

1. A system that tests a massive MIMO array antenna, the system including:

an anechoic chamber;

a mount for a MIMO array antenna positioned in the anechoic chamber, wherein the MIMO array antenna has at least 8×4 antenna elements that are individually activated to steer transmissions from the MIMO array antenna;

at least one pair of dual element antenna probes positionable in the anechoic chamber;

feeds coupling one or more UE sources to the dual element antenna probes, the UE sources generating RF in over-the-air communication with the MIMO array antenna, the UE sources emulating multiple UE devices;

base station electronics coupled to the MIMO array antenna;

a test controller coupled to the base station electronics;

wherein the test controller signals the UE sources over-the-air via the MIMO array antenna to invoke a connection to the UE sources and measure over-the-air channel performance between the MIMO array antenna and each of the multiple UE devices emulated, the performance including at least throughput; and

a first distribution of test probes in the anechoic chamber, wherein dual element antenna probes in the first distribution of test probes are substantially clumped in an area to allow the MIMO array antenna to observe isolation between directions to multiple users, then evaluating performance for the first distribution of test probes according to a reference direction of the MIMO array antenna, wherein the MIMO array antenna can be rotated or tilted or rolled to observe the performance when test probes fall at the center versus at an edge of array coverage.

2. The system of claim 1 , further including a single one of the at least a plurality of dual element antenna probes coupled to a single UE source.

3. The system of claim 1 , further including at least a first UE source and a second UE source, a first set of 2 or more probes coupled to the first UE source and a second set of 2 or more probes coupled to the second UE source and wherein the first set of 2 or more probes and the second set of 2 or more probes share at least one probe.

4. The system of claim 1 , wherein elements of at least one dual element antenna probe are substantially orthogonal, and further including applying a first signal from a first UE to a first element of the at least one dual element antenna probe and a second signal from a second UE to a second element of the at least one dual element antenna probe.

5. The system of claim 1 , further including increasing spacing between selected test probes in the anechoic chamber wherein dual element antenna probes of selected test probes are spatially distributed to allow the MIMO array antenna to observe a change in isolation between directions to multiple users, then evaluating performance for this set of test probes according to a reference direction of the MIMO array antenna, wherein the MIMO array antenna can be rotated or tilted or rolled to observe performance when test probes fall at the center versus at an edge of array coverage.

6. The system of claim 1 , further including a second distribution of a set of test probes in the anechoic chamber wherein dual element antenna probes in the set of test probes are substantially separated to allow the MIMO array antenna to observe a change in isolation between directions to multiple users, then evaluating performance for this set of test probes according to a reference direction of the MIMO array antenna, wherein the MIMO array antenna can be rotated or tilted or rolled to observe performance when test probes fall at the center versus at an edge of array coverage.

7. A method for testing a MIMO array antenna, the method including:

positioning a MIMO array antenna on a mount in an anechoic chamber, wherein the MIMO array antenna has at least 8×4 antenna elements that are individually activated to steer transmissions from the MIMO array antenna;

using at least one pair of dual element antenna probes positioned in the anechoic chamber, generating RF in over-the-air communication with the MIMO array antenna, with feeds coupling one or more UE sources to the dual element antenna probes, wherein the UE sources emulate multiple UE devices;

signaling the UE sources over-the-air via the MIMO array antenna, using base station electronics coupled to a test controller, connecting with the UE sources;

evaluating performance according to a reference direction of the MIMO array antenna for a first distribution of test probes in the anechoic chamber wherein dual element antenna probes in the first distribution of test probes are substantially clumped in an area to allow the MIMO array antenna to observe isolation between directions to multiple users, wherein the MIMO array antenna can be rotated or tilted or rolled to observe the performance when probes fall at the center versus at an edge of array coverage; and

measuring over-the-air channel performance between the MIMO array antenna and each of the multiple UE devices emulated, the performance including at least throughput.

8. The method of claim 7 , wherein a single one of the at least a plurality of dual element antenna probes coupled to a single UE source.

9. The method of claim 7 , further including at least a first UE source and a second UE source, a first set of 2 or more probes coupled to the first UE source and a second set of 2 or more probes coupled to the second UE source, and wherein the first set of 2 or more probes and the second set of 2 or more probes share at least one probe.

10. The method of claim 7 , wherein elements of at least one dual element antenna probe are substantially orthogonal, and further including applying a first signal from a first UE to a first element of the at least one dual element antenna probe and a second signal from a second UE to a second element of the at least one dual element antenna probe.

11. The method of claim 7 , further including:

increasing spacing between selected test probes within the anechoic chamber, wherein dual element antenna probes of selected test probes are spatially distributed to allow the MIMO array antenna to observe a change in isolation between directions to multiple users;

evaluating performance according to the reference direction of the MIMO array antenna for the test probes, wherein the MIMO array antenna can be rotated or tilted or rolled to observe performance when test probes fall at the center versus at an edge of array coverage.

12. The method of claim 7 , further including:

evaluating performance according to the reference direction of the MIMO array antenna for a second distribution of test probes in the anechoic chamber wherein dual element antenna probes in the second distribution of test probes are substantially separated to allow the MIMO array antenna to observe a change in isolation between directions to multiple users, wherein the MIMO array antenna can be rotated or tilted or rolled to observe performance when test probes fall at the center versus at an edge of array coverage.

13. A tangible non-transitory computer readable media with instructions that are combinable with a processor and memory coupled to the processor to carry out a method for testing a massive MIMO array antenna positioned within an anechoic chamber and having individually activated antenna elements to steer transmissions from the array, the method including:

using at least one pair of dual element antenna probes positioned in the anechoic chamber, generating RF in over-the-air communication with the MIMO array antenna, with feeds coupling one or more UE sources to the dual element antenna probes, wherein the UE sources emulate multiple UE devices;

signaling over-the-air via the MIMO array antenna, the UE sources using base station electronics coupled to a test controller, connecting with the UE sources;

evaluating performance according to a reference direction of the MIMO array antenna for a first distribution of test probes in the anechoic chamber wherein dual element antenna probes in the first distribution of test probes are substantially clumped in an area to allow the MIMO array antenna to observe isolation between directions to multiple users, wherein the MIMO array antenna can be rotated or tilted or rolled to observe the performance when probes fall at the center versus at an edge of array coverage; and

measuring over-the-air channel performance between the MIMO array antenna and each of the multiple UE devices emulated, the performance including at least throughput.

14. The tangible non-transitory computer readable media of claim 13 , wherein a single one of the at least a plurality of dual element antenna probes coupled to a single UE source.

15. The tangible non-transitory computer readable media of claim 13 , further including at least a first UE source and a second UE source, a first set of 2 or more probes coupled to the first UE source and a second set of 2 or more probes coupled to the second UE source, and wherein the first set of 2 or more probes and the second set of 2 or more probes share at least one probe.

16. The tangible non-transitory computer readable media of claim 13 , wherein elements of at least one dual element antenna probe are substantially orthogonal, and further including applying a first signal from a first UE to a first element of the at least one dual element antenna probe and a second signal from a second UE to a second element of the at least one dual element antenna probe.

17. The tangible non-transitory computer readable media of claim 13 , further including:

increasing spacing between selected test probes within the anechoic chamber, wherein dual element antenna probes of selected test probes are spatially distributed to allow the MIMO array antenna to observe a change in isolation between directions to multiple users; and

evaluating performance according to the reference direction of the MIMO array antenna for the test probes, wherein the MIMO array antenna can be rotated or tilted or rolled to observe performance when test probes fall at the center versus at an edge of array coverage.

18. The tangible non-transitory computer readable media of claim 13 , further including:

evaluating performance according to the reference direction of the MIMO array antenna for a second distribution of test probes in the anechoic chamber wherein dual element antenna probes in the second distribution of test probes are substantially separated to allow the MIMO array antenna to observe a change in isolation between directions to multiple users, wherein the MIMO array antenna can be rotated or tilted or rolled to observe performance when test probes fall at the center versus at an edge of array coverage.