Impact of Probe Coupling on Emulation Accuracy in Massive MIMO OTA Testing

The sectored multi-probe anechoic chamber (MPAC) setup has been proposed in the literature for OTA testing of massive MIMO base stations (BSs). However, the previous studies assume ideal isotropic probes, i.e., the radiation patterns and mutual coupling among the probe antennas have not been considered. In this paper, the impact of the mutual coupling of realistic probes on the simulation accuracy of two popular channel emulation methods, i.e. the pre-faded signal synthesis (PFS) method and the plane wave synthesis (PWS) method in the sectored MPAC system is investigated. Our results show that the PFS method is more robust to mutual coupling than the PWS method.