Increasing the volume of test zones in anechoic chamber MIMO Over-the-Air test set-ups

摘要

The purpose of Over-the-Air (OTA) testing is assessing the system performance of devices under test by emulating realistic radio environments. OTA testing is primarily important for systems whose performance is strongly influenced by the interaction between antenna and radio environment, as clearly applies to, for instance, mobile MIMO terminals. In the past, a much narrower definition was used. In the context of applications to mobile communications, “OTA” was understood as determining the TIS (Total Integrated Sensitivity) and TRP (Total Radiated Power) values for mobile SISO handsets. Present activities do not consider transmitted or received power itself but which communication performance the device under test is able to achieve with that power. The metrics to assess such performance are still discussed in ETSI 3GPP RAN4 [1]. The essence of Over-the-Air testing is the emulation of realistic radio environments, in order to assess the communication performance of devices under test with their antennas in interaction with the environment, especially with the advent of MIMO. To this end, the communication signals are to be convolved with the spatio-temporal characteristics of the mobile radio channel before they are received by the test object. Roughly speaking, two main categories of methods are considered in the present standardisation process for OTA testing of MIMO terminals [2]: 1. set-ups in stirred-mode reverberation chambers 2. set-ups in shielded/anechoic rooms.