Research on OTA Testing Optimization of 5G IoT Devices

Over-the-air (OTA) testing for wireless devices is crucial to guarantee actual network performance. Current OTA testing requires respectively 266 and 62 grid points for Total Radiated Power (TRP) and Total Isotropic Sensitivity (TIS) measurement. For 5G Internet of Things (IoT) devices, especially for low transmit duty-cycle devices, this number of grid points could lead to an unacceptably large amount of test time. Therefore, test time reduction is significant. The objective of this paper is to determine a suitable measurement grid for OTA testing of 5G IoT devices which balances measurement grid uncertainty/errors with test time. Two reference patterns representing a reasonable worst-case scenario of IoT devices are proposed for measurement uncertainty (MU) analysis of different grid configurations. The effects of different grid configurations on OTA testing accuracy are evaluated. The determination of associated MU term is proposed and determined based on statistical analysis. Finally, the reduction of grid points from currently required 62 (30/30 in theta/phi) to 32 (45/36) could save roughly 50% test time while requiring an uncertainty increase of less than 0.2 dB, which is acceptable for OTA testing of 5G IoT devices.