Reconfigurable Intelligent Surface-Based Receive Generalized Spatial Modulation Design

Receive generalized spatial modulation (RGSM), as an advanced type of receive spatial modulation (RSM), can be divided into diversity and multiplexing (MUX) schemes according to whether the symbols received by the selected antennas are the same. Recently, reconfigurable intelligent surface (RIS) assisted RSM has attracted much attention due to better reception performance and spectral efficiency. The RIS-aided RGSM (RIS-RGSM) with diversity scheme is realized in this paper via a simple improvement based on the state-of-the-art RIS-aided receive generalized space shift keying (RIS-RGSSK) scheme. To increase the transmission rate, the RIS-RGSM with MUX scheme is proposed in this paper, which adjusts the reflecting phase shifts and on/off states of RIS elements. Theoretical analysis and numerical simulations show that the proposed RIS-RGSM with MUX scheme has better bit error rate (BER) performance than the diversity scheme. Compared to the RIS-RGSSK scheme, the proposed RIS-RGSM scheme can significantly reduce the number of receive antennas while maintaining the transmission rate.