Probe Selection and Power Weighting for MIMO OTA Testing with Multiple Users

Abstract

This paper discusses multiple-input multiple-output (MIMO) over-the-air (OTA) test for multiple users based on multi-probe anechoic chamber (MPAC) method. The spatial correlation is used as a criterion to evaluate the accuracy of the reconstructed channel model. In order to test multiple user equipments (UEs) at the same time and reproduce the target channel model more accurately, the number of channel emulators and probes needs to be increased, which will increase the testing system cost. However, the traditional algorithm can not minimize the correlation error between the real radio environment and the emulated channel environment very well because it substitutes the sum of power angular spectrums (PASs) for multiple users into the optimization function. Given this problem, a novel MIMO OTA optimization method for multiple users is proposed in this paper, which directly balances the probe position according to the different mean angles-of-arrival (AoAs) of each user and minimizes the sum of correlation errors for all users. Moreover, the simulation results show that the proposed method is superior to the traditional and reference algorithm.