Validation of Ray-tracing Simulated Channels for Massive MIMO Systems at Millimeter-wave Bands

Employing large-scale antenna configuration is seen as a key enabling radio technology for 5G and beyond communication systems. This work presents validation of a home-developed ray tracing (RT) tool for massive multiple-input multiple-output (MIMO) system in the millimeter-wave (mmWave) frequency bands. For this purpose, a channel sounding campaign in an indoor entrance scenario using a massive MIMO systems based on virtual array concept is presented. The channel measurement of 6 GHz bandwidth (26.5-32.5 GHz) is first demonstrated, with a virtual uniform circular array (UCA) consisting of 720 antenna elements located at the transmitter position on the turntable and one antenna at the receiver position. The impact of order of interactions e.g. reflections and diffractions on the channel impulse responses (CIRs) is analyzed in the RT simulation. The comparison between RT simulated and measured results shows a reasonable level of agreement.