Performance evaluation of RIS-based SSK and SM schemes with perfect and imperfect channel phase estimation over Weibull fading channels

In this paper, we present the re-configurable intelligent surfaces (RIS) based space shift keying (SSK) and spatial modulation (SM) schemes with both perfect and imperfect channel phase knowledge over Weibull fading environments. At the receiver, we consider the sub-optimal Greedy Detection (GD) for proposed RIS-based SSK and SM schemes. Central Limit Theorem (CLT) caused by RIS schemes facilitates to adopt of a unified framework for error performance analysis of Weibull fading channels without loss of generality. In this study, it has been obtained the theoretical bit error probability (BEP) of the proposed schemes. It should be underlined that unlike the literature, the BEP of the proposed schemes is formulated in the presence of a Gaussian imperfect phase estimation at RIS. These analytical results were then validated with Monte-Carlo Simulations under the various system settings (e.g., the severity of fading parameters, number of reflectors, different antenna numbers).