Fourth-generation (4G) wireless relies on Multiple-Input Multiple-Output (MIMO) technology to deliver on the promises of higher data rates, greater coverage areas, and lower operational costs. However, the performance of MIMO-based mobile devices is especially sensitive to antenna design, motion and a host of other factors that were less significant in single-antenna designs. This places new emphasis on Over-the-Air (OTA) testing of MIMO devices.

MIMO-OTA tests are usually performed using a chamber-based method, in which wireless channel emulators apply real-world spatial channel models to the signals that are sent to antenna probes mounted in the chamber. This enables the user to precisely characterize how well a mobile device with MIMO receives signals with these real-world spatial properties, which are arriving from a specific direction.

Spirent’s MIMO OTA Environment Builder software allows the test operator to select the desired mobile environment, and then automatically configures a Spirent wireless channel emulator to correctly supply the multiple signals to the chamber. An intuitive graphical interface wraps the complexities of chamber-based MIMO-OTA testing into a clear, easy-to-use control and feedback mechanism. Unlike competitive approaches, the Spirent solution allows the mobile environment to be reconfigured in real time, increasing test coverage while reducing test time.

As a recognized leader in both RF channel emulation and MIMO-OTA testing, an important development goal for Spirent’s new VR5 HD Spatial Channel Emulator was to create a single bench-top unit that could easily and accurately manage the most demanding MIMO-OTA test cases. When the MIMO OTA Environment Builder software is used with Spirent’s VR5 or SR5500 channel emulators and an RF chamber such as Spirent octoBox or a chamber from a Spirent partner, creating the complex spatial fields required in MIMO OTA testing is quick and simple.