ETS-Lindgren's AMS-7000 Wireless OTA Reverb Test System

The AMS-7000 uses two Z fold tuners, a DUT turntable, and a measurement antenna turret to improve isotropicity and homogeneity. These features allow the system to make measurements at different speeds and levels of accuracy.

SISO TRP, TIS, and Throughput

TRP measurements made in a reverb chamber rely on a continuous sampling of the average power density in an over-moded environment while the DUT is transmitting at its full power. The accuracy, with which the average power can be measured, directly correlates with the number of independent samples that are available to be taken. The TIS measurement is the converse of TRP; the power density in the chamber is controlled for the downlink path by the communication tester. The DUT responds to samples of this environment as it moves to a series of different locations in the varying modal environment. The TIS value is then derived from the reported data validity threshold after chamber corrections are applied. The reverb chamber's over-moded environment also means that the precise location of the DUT is not critical to achieve good measurement repeatability or accuracy, resulting in reduced setup time.

MIMO Throughput Measurements

MIMO throughput is ultimately a measure of the ability of the DUT to maximize its data throughput under different controlled environmental multipath conditions. The reverb chamber is already a multipath environment with path lengths limited by the chamber dimensions exhibiting a signal decay profile dependent on the loss in the chamber.
For MIMO throughput measurements, a simplified representation of the real world environment can be created by duplicating how the averaging effect of the chamber would be seen by a MIMO device. Different delay profiles can be realized by changing the selection of small RF Absorber loading elements fitted to the chamber. Additional delays and more complex propagation models can be introduced with an optional channel emulator.