多天线系统中的多维极化分集性能分析

Performance analysis of multi-polarization diversity in MIMO wireless communications

分别研究了六维极化元天线和三维极化偶极子天线模型的空域相关矩阵,计算了系统的信道容量和有效空间自由度(EDOF)。通过定义更广义的角谱分布,指出了在六维极化的元天线模型中,平均入射角对系统性能起着关键的作用,而入射角谱的对称性也是导致元天线模型中低相关性的主要原因;通过对三维正交极化的半波偶极子结合矩量法和蒙特卡罗方法计算,论证了在散射丰富条件下应用三维极化天线,可获得接近三倍单天线信道容量的增益,从而验证了已有的测试结果;最后给出了三维正交极化天线的设计思路。

The correlation properties of electric and magnetic current point sources models and tri-polar dipole model are analyzed respectively in this paper. The channel capacity along with effective degrees of freedom （EDOF） is calculated base on the obtained correlation matrix. By defining more general PAS in the point sources model, it is pointed out that the MIMO performance is severely affected by the mean incident angle, also, the low correlation properties of the point source model are mainly due to the symmetry of PAS. Through the capacity analysis of dipole model by Moment method and Monte Carlo methods, it is concluded that triple capacity can be available in rich scatters environment, and this theory prediction is agree well with the measurement result. The design methods of tri-polar antennas are discussed at last.