Performance of RIS-Assisted Full-Duplex Space Shift Keying With Imperfect Self-Interference Cancellation

TL;DR

This paper analyzes the performance of a full-duplex RIS-assisted space shift keying system considering imperfect self-interference cancellation, deriving error probabilities and demonstrating mitigation strategies through simulations.

Contribution

It introduces a comprehensive analysis of FD RIS-SSK systems with residual interference, providing new error probability expressions and insights into interference mitigation.

Findings

Self-interference and loop interference severely impact performance.

Increasing RIS units effectively mitigates interference effects.

Derived high-SNR error probability expressions validated by simulations.

Abstract

In this paper, we consider a full-duplex (FD) space shift keying (SSK) communication system, where information exchange between two users is assisted only by a reconfigurable intelligent surface (RIS). In particular, the impact of loop interference (LI) between the transmit and receive antennas as well as residual self-interference (SI) from the RIS is considered. Based on the maximum likelihood detector, we derive the conditional pairwise error probability and the numerical integration expression for the unconditional pairwise error probability (UPEP). Since it is difficult to find a closed-form solution, we perform accurate estimation by the Gauss-Chebyshev quadrature (GCQ) method. To gain more useful insights, we derive an expression for UPEP in the high signal-to-noise ratio region and further give the average bit error probability (ABEP) expression. Monte Carlo simulations were performed to validate the derived results. It is found that SI and LI have severe impacts on system performance. Fortunately, these two disturbances can be well counteracted by increasing the number of RIS units.