Platform to simulate MIMO scenarios in the laboratory
MTS Systemtechnik has developed the MIMO Tester as an optimal platform for simulating MIMO scenarios in the lab. This device is suitable both for emulating antenna diversity and for beamforming and can be used for HSPA+, LTE or WLAN tests. The channel matrix can be emulated by attenuators and delay lines, each of which can be digitally adjusted (see principle diagram). Each level of a channel can be programmed in a range from 0 to 95 dB in 1 dB steps. Phase differences between individual channels can also be emulated by corresponding time delays of up to 1600 picoseconds (ps), depending on the signal frequency used. The delay lines can be programmed in the range from 0 to 640 ps in 5 ps steps and from 640 ps to 1600 ps in 10 ps steps. The MIMO tester is purely passive and therefore allows both signal directions.
An example of a MIMO tester is the AIAD-8/8-4G-DL (see block diagram). This emulator contains a total of 64 channels, each with a programmable attenuator and a programmable delay line. With this very flexible emulator it is possible to test a variety of MISO, SIMO or MIMO configurations as well as multi-user MIMO quickly and reproducibly in the laboratory. The AIAD-8/8-4G-DL has a maximum input power of 5 Watt each input and can be used from 0.5 to 4 GHz (optional 6 GHz). The insertion loss is a maximum of 44 dB. Correction tables to compensate for existing tolerances are also supplied with the device.