A Novel Probe Selection Method for OTA Testing of 5G Massive MIMO Base Station on Static and Dynamic Channel

Over-the-air (OTA) testing technology has been applied to the millimeter wave massive multi-input-multi-output (MIMO) devices due to its advantages of simplicity and flexibility. The sectored multi-probe anechoic chamber (MPAC) is considered as the most promising method for massive MIMO base station OTA testing, but the performance of channel reconstruction in MPAC is restricted by probe arrangement and power weight. Due to the large number of probes, the cost of the sectored MPAC system is greatly increased. It is crucial to reduce the number of probes used while achieving high reconstruction accuracy. However, because of the high computational complexity, the probe selection methods suitable for the probe ring in two-dimensional MPAC are not applicable for sectored MPAC, especially for dynamic channels. This paper proposes a novel method to select the active probes for channel reconstruction. In order to verify the effectiveness of the proposed algorithm, the root mean square error of the spatial correlation and power angular spectrum similarity percentage are used as the factors of merit. The static channel and dynamic channel are simulated respectively. The simulation results show that the novel algorithm can select the probes efficiently and achieve good reconstruction accuracy.