N.2 Fading channel emulator output uncertainty
37.5443GPPConformance testingRelease 16TSUniversal Terrestrial Radio Access (UTRA) and Evolved UTRA (E-UTRA)User Equipment (UE) Over The Air (OTA) performance
In the case where a fading channel emulator is used, the outputs of the fading channel emulator are used to drive signals through the amplifiers, if necessary, to the probe antennas in the MIMO OTA tests either as an absolute level or as a relative level. The receiving device used is a UE. Generally, an uncertainty contribution comes from the absolute level accuracy, non-linearity, and output signal stability of the fading channel emulator. All of the contributions should be considered. However, the applicability of each contribution is contingent on the specific measurement implementation and calibration procedure.
This uncertainty should be determined from the manufacturer’s data sheet expressed in dB with a rectangular distribution, unless otherwise informed (see clause 5.1.2 in ). Furthermore, the uncertainty of the non-linearity and the output signal stability of the device may be included in the absolute level uncertainty. If not, the non-linearity, output signal stability and output signal stability versus temperature should be determined from the manufacturer’s data sheet. Once determined, the non-linearity uncertainty and the output signal stability uncertainties should be combined with the output uncertainty using the RSS method.