RIS-Assisted Receive Generalized Space-Shift Keying and Receive Generalized Spatial Modulation

In this letter, we enhance the performance of wireless communication systems by utilizing reconfigurable intelligent surface (RIS) and index modulation (IM). In particular, we introduce two schemes: RIS-assisted receive generalized space-shift keying (RIS-RGSSK) and RIS-assisted receive generalized spatial modulation (RIS-RGSM). In the RIS-RGSSK scheme, information bits are conveyed through selection of multiple receive antennas. The RIS-RGSM scheme takes RIS-RGSSK a step further by conveying information bits not only through the selection of multiple receive antennas, but also through embedding information bits in the phase of the received signals using M-ary phase shift keying (PSK) modulation. We also present simple yet efficient greedy detectors (GDs) for non-coherent detection of both schemes. Simulation results demonstrate the advantages of our proposed methods over existing schemes such as the RIS-assisted receive quadrature space-shift keying (RIS-RQSSK).