MIMO device performance measurements in a wireless environment simulator

Over-the-air performance testing of MIMO wireless devices requires the simulation of an RF environment similar to that experienced in the real world. There are a number of standardized spatial channel models that are considered acceptable for evaluating MIMO performance of LTE devices. A number of different methods have been proposed for generating MIMO test environments, but the ability of those methods to reproduce a target wireless channel, and the results they produce, vary. There are several methods for evaluating a spatial channel that are useful validation tools if the goal is to produce a specific known environment. This paper will present the results from several of those for different test cases. In addition, a set of reference device antenna systems have been developed to allow one MIMO radio to be tested with antennas designed for "good", "nominal", and "bad" performance. In this way, the ability of a MIMO test system to provide a relative distinction between different levels of device performance may be assessed. This paper will show results of this comparison for different system configurations and channel models and provide an indication of the suitability of these systems for evaluating MIMO device performance.