Massive multiple input multiple output (MIMO) improves transmission rate without increasing the complexity on signal processing by employing a large number of antennas at a base station. The effect of applying massive MIMO to small cells at the 2-GHz band has been reported. However, the primary targets of massive MIMO are small cells at a highfrequency band, because antenna size is considerably large when considering massive MIMO in a macro frequency band. In this study, measurements are performed for actual propagation channels using a wideband channel sounder with a horn antenna in the 20-GHz band in an actual indoor propagation environment. Moreover, the performance of interference rejection is evaluated using a virtual circular array antenna with 24 elements. Keywords: massive MIMO, indoor propagation characteristics, 20-GHz band, circular array, maximum ratio combining, zero forcing Classification: Antennas and Propagation , vol. 31, no. 2, pp. 160-171, Feb. 2013. DOI:10.1109/JSAC.2013 H. Yang and T. L. Marzetta, "Performance of conjugate and zero-forcing beamforming in large-scale antenna systems," IEEE J. Sel. Areas Commun., vol. 31, no. 2, pp. 172-179, Feb. 2013. DOI:10.1109/JSAC.2013 S. Suyama, J. Shen, T. Obara, M. Sumi, M. Nakajima, and Y. Okumura, "Basic performances of super high bit rate massive MIMO transmission using higher frequency bands," IEICE
References