Two-Way Full-Duplex Spatial Modulation Enabled by RISs with Prewired Transmit Phase-Offset

To address the increasing demand for transmission systems with enhanced efficiency and flexibility, two-way (TW) full-duplex (FD) systems have become a vital research focus in wireless communications. In this paper, a novel reconfigurable intelligent surfaces (RISs) assisted TW-FD spatial modulation (SM) model is proposed to improve the transmission reliability performance. With this proposal, we introduce the transmit-side SM to activate single antenna for fulfilling the transmission of amplitude and phase modulated symbols. The transmission is then reflected by the corresponding RIS to the antenna at the receiver end. Moreover, the prewired phase-offset (PPO) is included in the transmission process for attaining enhanced detecting reliability. To evaluate the performance boundaries of the proposed system, we consider the maximum likelihood detection based analytical derivations. More specifically, upon utilizing the moment generating function method, we derive the closed-form results for the system average bit error probability. Finally, with the simulation based comparative analysis, we verify the reliability and efficiency of the proposed TW-FD-RIS-PPOSM system.