An improved method for power and SIR validation on MPAC MIMO OTA system

MIMO OTA testing is becoming a very practical solution to evaluate the wireless terminal performance for high data rate protocols like LTE, LTE-A, 802.11ac,Wi-Fi, etc. Power and SIR (Signal to Interference Ratio) validations are very important for a MIMO OTA system. The results of power and SIR validation tests can confirm that the test settings and correction data from calibration have been applied properly. The CTIA Test Plan for 2×2 Downlink MIMO and Transmit Diversity Over-the-Air Performance only provides the basic concept of the validation, but does not provide implementation details. This paper provides the detailed background information for the use of linearly polarized reference electric dipoles to validate the power and SIR of a Multi-Probe Anechoic Chamber (MPAC) MIMO OTA system. The entire process can be integrated into an automated measurement procedure that requires only a change of dipole polarization as a manual step. Further, some key parameter settings will be emphasized in this paper.