Basic performance of massive MIMO in indoor scenario at 20-GHz band

Massive multiple input multiple output (MIMO) enables the improvement on the transmission rate without increasing the burden on the signal processing by employing a large number of antennas at a base station. It was reported an effect of applying a massive MIMO to small cell at the 2-GHz band. However, main target of the massive MIMO will be the small cells at the high-frequency band, because the antenna size is very large when considering the massive MIMO in macro frequency band. In this paper, real propagation channels are measured by using a wideband channel sounder with horn antenna in 20-GHz band in an actual indoor propagation environment. Moreover, the performance of the interference rejection is evaluated when virtual circular array antenna with 24 elements is assumed.