Measurement-based delay spread analysis of wideband massive MIMO system at 3.5 GHz

Massive multiple-input multiple-output (MIMO) ultra-wideband channel plays an important role in studying the fifth generation (5G) mobile communication system. The measurement is carried out in outdoor-to-indoor (O2I) scene non-line of sight (NLoS). The frequency is 3.5 GHz and bandwidth is 100 MHz and 200 MHz respectively. Through the analysis of measurement data, two problems are explored in this paper. One is the method used to evaluate delay spread in such a large number of sub-channel system. Another is the effect of the transmission bandwidth and antenna number. The results reflect that array positions and measurement environments have various influences on delay spread. In addition, contrasting the results of different bandwidth, it clearly indicates that the delay spread of 100 MHz is greater.