RIS辅助MIMO通信信道外推技术研究

RIS辅助MIMO通过部署大量无源反射单元,主动调控电磁波,实现无线环境可编程新范式。利用此优势的关键为高精度RIS信道获取。同时发挥RIS的电磁调控能力,利用部分RIS信道同全部RIS信道之间的确定性映射关系,提出实用的RIS信道外推框架。首先,基于电磁传播理论,拓展电磁空间重构机理,解释信道外推可行性,精准表征RIS链路电磁特性。其次,探寻电磁散射参数集合同部分RIS信道的耦合机理。以此为基础,给出基于贝叶斯统计推断和深度学习的RIS辅助MIMO信道外推方案。这些技术将极大降低信道训练开销,为RIS辅助MIMO实用化提供理论依据和技术支撑。

SOLVING THE PROPAGATION OF ELECTROMAGNETIC WAVE IN A SIMPLE TWO-DIMENSIONALINHOMOGENEOUS MEDIUM BASED ON SYMPLECTIC GEOMETRICAL THEORY

A new symplectic geometrical high-frequency approximation method for solving the propagation of electromagnetic wave in the two-dimensional inhomogeneous medium is used in this paper. The propagating caustic problem of electromagnetic wave is translated into non-caustic problem by the coordinate transform on the symplectic space. The high-frequency approximation solution that includes the caustic region is obtained with the method combining with the geometrical optics. The drawback that the solution in the caustic region can not be obtained with geometrical optics is overcome by this method. The results coincide well with that of finite element method.