Antenna selection method employing orthogonal polarization and radiation patterns for MIMO antenna

This paper proposes a simple antenna selection method that is suitable for the MIMO (Multi-Input Multi-Output) terminal antenna employing orthogonal polarizations and patterns. The combination of the antenna elements with the orthogonal polarizations and patterns is effective in reducing the antenna coupling and spatial correlation. As a basic consideration, a configuration of three orthogonal dipoles, which is the simplest configuration with orthogonal polarizations and patterns, is investigated to clarify the effectiveness of the antenna selection method. In this method, the vertical antennas, which tend to exhibit a high signal-to-noise ratio, are always used. This method allows the use of a fairly simple RF-switch circuit because the number of the antenna combinations is reduced. Based on numerical analysis, the proposed method provides channel capacity that is as high as that provided by the ideal antenna selection.