Over-the-Air Testing of MIMO-Capable Terminals: Evaluation of Multiple-Antenna Systems in Realistic Multipath Propagation Environments Using an OTA Method

Abstract

Over-the-Air Testing of MiMO-Capable Terminals new over-the-air (OTA) testing method is required for evaluating multiple-antenna systems in realistic multipath propagation environments. Antenna design and propagation channels are the two key parameters that ultimately determine the multiple-input, multiple-output (MIMO) device performance. As antennas are inherently included in OTA testing, it is important to also consider realistic channel models for MIMO device-performance evaluation. This article shows that the multiprobe anechoic chamber (MPAC) setup is capable of emulating realistic and accurate multipath environments, making it a suitable method for testing terminals equipped with multiple antennas. In comparison to the mode-stirred reverberation chamber (RC) setup that represents an isotropic multipath environment, the MPAC method is capable of generating arbitrary spatial channel models with polarization characteristics. This article addresses some of the key aspects associated with MPAC systems, such as methods to reproduce spatial channel

A Method of Implementing a 4 × 4 Correlation Matrix for Evaluating the Uplink Channel Properties of MIMO Over-the-Air Apparatus

“…Cluster environment [13] Channel emulation technique [14] Plane-wave field synthesis [15] Bit error rate, IoT wireless device [16] 3D channel model, probe selection [17] Base station Radiated testing of massive MIMO [18] Probe selection algorithm [19] In a reverberation chamber based method, the chamber refers to a metallic cavity or cavities that can emulate an isotropic multipath environment that represents a reference environment for systems designed to work during fading [9,10]. The Rayleigh propagation environment in a chamber is well known as a good reference for mobile terminal systems in urban environments.…”

“…In the multiple probe antenna based method, such as one with a fading emulator, a number of test antenna probes located in the chamber reproduce the channel characteristics in a controlled and repeatable manner to test MIMO performance [13][14][15][16][17]. The disadvantage of this method is that it requires many instruments, such as a probe antenna, a power divider, and a phase shifter.…”

“…In OTA testing, investigations primarily focus on evaluating the performance of mobile terminals in downlink channels [9][10][11][12][13][14][15][16][17]. For the uplink channel, OTA testing of a massive MIMO BS has been conducted; however, MIMO terminal OTA testing has not yet been reported [18,19].…”