RIS Group Number Modulation Assisted Receive Spatial Modulation

Reconfigurable Intelligent Surface (RIS) has gained significant attention as a potential solution to improve wireless communication by manipulating signal propagation. Spatial modulation (SM) techniques have been extensively used to boost spectral efficiency by leveraging antenna indices for data transmission. Receive spatial modulation (RSM) further simplifies receiver structures while improving system performance. Inspired by advancements in RIS-assisted communication systems, this paper introduces a novel RIS group number modulation assisted receive spatial modulation (RGNM-RSM) scheme. The proposed approach divides the RIS into multiple groups and modulates the number of activated RIS groups alongside selecting the receive antenna, leveraging information bits to maximize the instantaneous signal-to-noise ratio (SNR) at the destination. Two schemes, RGNM-RSSK and RGNM-RSM, are developed, with the latter incorporating M-ary modulation for additional data transmission. Monte Carlo simulations proved that the RGNMRSM scheme outperform others in terms of the performance of the average bit error probability (ABEP) and the spectral efficiency. The findings highlight the potential of RGNM-RSM in achieving reliable and efficient wireless communication.