Probe Selection in Multiprobe OTA Setups

Standardization work for over-the-air (OTA) testing of multiple-input-multiple-output (MIMO) capable terminals is currently ongoing in COST IC1004, 3GPP, and CTIA, where a multiprobe anechoic chamber based method is a promising candidate. Setting up a multiprobe configuration with channel emulators is costly, so finding ways to limit the number of probes while still reproducing the target channels accurately could make the test system both cheaper and simpler to implement. Several probe selection algorithms are presented in this paper to address this issue. The proposed techniques provide a probe selection framework for the channel emulation techniques published in the literature. Simulation results show that good channel emulation accuracy can be achieved with the selected subset of probes for the considered target channel models. The probe selection algorithm is further supported by measurement results in a practical multiprobe setup.