Hybrid RIS-Assisted Receive Generalized Space Shift Keying for Wireless Communication

This paper presents a hybrid reconfigurable intelligent surface-assisted receive generalized space shift keying (HRIS-RGSSK) scheme to mitigate multiplicative fading in RIS-assisted systems while enhancing system spectral efficiency (SE). In this scheme, information bits are jointly encoded by the number of active groups and the indices of the receive antennas. Specifically, reflection elements of the RIS are partitioned into groups that can be configured into either active or passive states. Meanwhile, the GSSK technique is applied at the receiver to achieve higher receive diversity gain to further improve SE. In addition, we derive a theoretical upper bound for the bit error rate (BER) and propose a low-complexity (LC) detector to reduce computational overhead. Simulation results confirm the accuracy of the theoretical derivations and validate the superiority of the proposed scheme in terms of complexity, SE and BER.