| （英） |
Very wide bandwidth of 7 to 9GHz is available in 60GHz band for unlicensed use on a world-wide basis, however MIMO transmission will be necessary to achieve over 10Gbps transmission even in 60GHz band. As the directional antenna is
used in 60GHz WLAN/WPAN, the propagation in 60GHz band is mainly line-of-site (LOS) and it is difficult to secure the un-correlated paths for MIMO transmission. To solve this problem, the authors have been proposing an orthogonal polarization based MIMO transmission using liner polarization waves, i.e. vertical wave and horizontal wave. The previous report shows the transmission quality of each polarization waves is not equal when liner polarization is employed, i.e. vertical wave and horizontal wave. To solve this problem, the authors proposed to use the circular waves instead of liner polarization. This report evaluates the transmission performance, e.g. channel capacity and BER, of the proposed 60GHz orthogonal polarization based MIMO using circular polarization waves in indoor environments, where the ray-tracing method is employed for computer solutions. It also describes the comparison with 60GHz MIMO using liner polarization waves. |