The 5th generation mobile communication system (5G) incorporates the latest technologies such as OFDMA, LDPC codes and millimeter wave in addition to MIMO. In order to evaluate the propagation characteristics of such a complex system, it is very difficult to evaluate the propagation characteristics at multiple frequencies. In this paper, we propose a method for estimating the Datarate of wideband MIMO systems such as 5G using narrowband signals such as CW signals. In this paper, we propose an extension of this method to multiuser systems, and show the effectiveness of this method by applying it to measured data.