Xiangyu Chen

TL;DR: In this article, free-space path loss models for RIS-assisted wireless communications are developed for different scenarios by studying the physics and electromagnetic nature of RISs, which reveal the relationships between the free space path loss of RIS assisted wireless communications and the distance from the transmitter/receiver to the RIS, the size of the RIS and the radiation patterns of antennas and unit cells.

TL;DR: The proposed models, which are first validated through extensive simulation results, reveal the relationships between the free-space path loss of RIS-assisted wireless communications and the distances from the transmitter/receiver to the RIS, the size of the ris, the near-field/far-field effects of the RIS and the radiation patterns of antennas and unit cells.

TL;DR: In this paper, a dual-polarized reconfigurable intelligent surface (RIS) based MIMO transmission architecture is proposed to achieve modulation and transmission of multichannel signals without the need for conventional RF chains.

TL;DR: In this article, the impact of the radiation patterns of the antennas and unit cells of the RISs is formulated in terms of an angle-dependent loss factor, which gives more accurate estimates of the path loss of RISs comprised of unit cells with a deep sub-wavelength size.

TL;DR: In this article, the authors show that there still exists channel reciprocity for RIS-assisted wireless networks satisfying certain conditions, and they also experimentally demonstrate the reciprocity at the sub-6 GHz and the millimeter-wave frequency bands by using two fabricated RISs.