ABER analysis of RIS-aided SSK schemes over Ricean fading channels

Abstract

Reconfigurable intelligent surface (RIS) is a promising technology to meet the needs of next-generation wireless communication techniques that enhance the quality of service by effectively adjusting the phases of the signals through a reflective surface. On the other side, space shift keying (SSK), as one of the typical index modulation (IM) techniques, provides data transmission by using only the information of the active transmitting antenna index instead of applying traditional modulation methods. In this study, two of the RIS-assisted SSK schemes are studied to take potential benefits of both RIS and SSK techniques, and the average bit error rate (ABER) performance is investigated over Ricean fading channels. The activated transmitter antenna for each transmission instant is detected by utilizing the maximum likelihood (ML) detection algorithm at the receiver side. The ABER performance of the proposed RIS-based systems in proportion to the increasing number of reflecting elements and Ricean-K factor is presented by both theoretical derivations and computer simulations. The obtained results show that the Ricean-K parameter and the number of reflective elements on the RIS have an undeniable effect on the system performance.