Inverse Matrix Autosearch Technique for the RTS MIMO OTA Test

An inverse matrix autosearch algorithm for radiated two-stage (RTS) multiple input and multiple output (MIMO) over-the-air (OTA) tests is proposed in this article. The RTS is one standard technique for the MIMO OTA test provided by the Cellular Telecommunication and Internet Association and the Third Generation Partnership Project. A basic step in the RTS test procedure is to solve the inverse matrix at a combination of measurement antennas and device orientation. The automatic solving algorithm proposed in this article is based on two parts: the technique for selecting an appropriate combination for inverse matrix solving and the method for solving the inverse matrix at a fixed combination. The technique proposed in this article makes the RTS test procedure automatic and fast, which improves the test user experience. In fact, only 2 min are required for the whole process of the appropriate combination calculation and the inverse matrix solving at the selected combination, while several hours might be needed using the traversal method.