Realization of Reconfigurable Intelligent Surface-Based Index Modulation Transmission

Reconfigurable intelligent surface (RIS) and index modulation (IM) are two emerging technologies, which show great potentials to achieve green and clean wireless communications, attracting extensive attention in recent years. This paper designs and implements an RIS-based IM transmission scheme that effectively integrates the two techniques. By utilizing the characteristics of RIS to realize flexible control of electromagnetic waves in a reconfigurable manner, IM wireless transmission can be directly realized without conventional radio frequency chains. The proposed approach is validated through the prototype system which is set up based on a fabricated phase-programmable RIS operating in the sub-6GHz frequency band. The experimental results convincingly verify the feasibility of the proposed scheme and suggest that RISs offer a cost-effective hardware architecture to realize IM with massive transmitting antennas.