Copula-Based Reliability Analysis of RIS-Aided Short-Packet Communication With EMI

Abstract

This letter analyzes the impact of electromagnetic interference (EMI) on the average block error rate (BLER) of reconfigurable intelligent surface (RIS)-aided short-packet communication (SPC) systems with statistical channel state information over Rician fading. To capture the correlation between EMI and the transmitted signal power caused by their common dependence on the channel from the RIS to the user, we employ Copula theory. Specifically, we characterize the received signal-to-interference-plus-noise ratio statistics for both continuous and discrete phase shifts, and identify the Gaussian copula as the most accurate choice. The average BLER of the considered RIS-aided SPC system is then analyzed. Finally, simulation results validate our theoretical analysis, revealing that the independence assumption overestimates the average BLER under strong EMI, whereas the Gaussian copula maintains high accuracy in both weak and strong EMI regimes.