Characterization of massive MIMO UWB channel for indoor environments

Massive multiple-input multiple-output (MIMO) is one of the promising candidate technologies in communications engineering that can potentially increase the capacity and reliability of next generation wireless systems. In ultrawideband (UWB) systems, utilization of massive MIMO schemes can result in an improvement in the UWB system capacity and UWB communications range. In this paper, we introduce a measurement set-up to characterize massive MIMO channels for a UWB system in two typical indoor environments. We consider a 10×10 planar array and study the massive MIMO UWB channel based on virtual array measurements for the frequency range of 3.1–5.3 GHz, with a signal bandwidth of 2.2 GHz. We investigate the time dispersion characteristics, a form of Ricean K-factor, and received power, which collectively provide insight into the spatial variations among different antenna elements in these channels. Results show the fluctuation of about 4 dB in the receive power of different array elements and for both measurement environments. Moreover, the “static” K-factor is ranging between −9.2 to −3.27 dB, and the RMS delay spread is as low as 4.22 ns, showing a very low value in comparison to other measurements at different frequencies.