RIS-assisted MIMO THz Communication Systems with Spatial Modulation: A Performance Analysis

Abstract

In recent years, reconfigurable intelligent surfaces (RIS) have emerged as a promising technology for enhancing link reliability in wireless communication systems. This paper introduces a novel RIS-assisted terahertz (THz) communication system utilizing the spatial modulation (SM) technique. We derive the closed-form expressions for the probability density function (PDF) and moment generating function (MGF) of the SM-based RIS-assisted THz system over α-μ fading. Leveraging these derived channel statistics, we obtain an upper bound on the average bit error rate (BER) and a lower bound on the ergodic capacity to evaluate the performance of the proposed system. The asymptotic BER is analyzed to determine the system's diversity gain. The numerical results validate the theoretical findings and provide valuable insights into the system's performance. The analysis shows that the SM-based RIS-assisted THz system outperforms the existing traditional systems. Lastly, a trade-off between average BER performance and spectral efficiency is observed. © 1972-2012 IEEE.