3.52-GHz MIMO radio channel sounder

This paper presents a radio propagation measurement system for wideband multiple-input-multiple-output (MIMO) measurements at 3.52 GHz. MIMO channel matrix of size 7times7 can be measured using fast microwave switches at the transmitter (TX) and the receiver (RX).The system is capable of measuring the direction of departure (DOD) and direction of arrival (DOA) in the vertical polarization in both TX and RX. Besides, the transmitter of the system can be put on a vehicle to enable measurement of the radio channel with a Doppler frequency range of 398.6 Hz. The system can also support continuous measurement for more than 10 hours which is much longer than former channel sounder. The antenna array configuration is selected to be uniform linear. Calibration in an anechoic chamber of the directional characteristics of the antenna array is performed. And a model for the calibration with data measured in a small anechoic chamber is proposed. Results from the calibration and from indoor measurement campaigns are shown.