Space-frequency-polarization-division multiplexed wireless communication system using anisotropic space-time-coding digital metasurface

Abstract In the past years, wireless communications based on digital coding metasurfaces have gained research interests owing to the simplified architectures and low costs. However, in most of the metasurface-based wireless systems, single-polarization scenario is used, limiting the channel capacities. To solve the problem, multiplexing methods have been adopted, but the system complexity is inevitably increased. Here, a space-frequency-polarization-division multiplexed wireless communication system is proposed using an anisotropic space-time-coding (STC) digital metasurface. By separately designing time-varying control voltage sequences for differently oriented varactor diodes integrated on the metasurface, we achieve frequency-polarization-division multiplexed modulations. By further introducing different time-delay gradients to the control voltage sequences in two polarization directions, we successfully obtain space-frequency-polarization-division multiplexed modulations to realize new-architecture wireless communication system. The new communication system is designed with compact dual-polarized meta-elements, and can improve the channel capacity and space utilization. Experimental results demonstrate high-performance and real-time transmission capability of the proposed communication system, confirming the potential applications in multiple-user collaborative wireless communications.