Multi-RIS-Aided Wireless Systems: Statistical Characterization and Performance Analysis

In this paper, we study the statistical characterization and modeling of distributed multi-reconfigurable intelligent surface (RIS)-aided wireless systems. Specifically, consider a practical system model where RISs with different geometric sizes are distributively deployed, channels associated to assumed be independent but not identically (i.n.i.d.). We propose two purpose-oriented multi-RIS-aided schemes, namely, exhaustive RIS-aided (ERA) opportunistic (ORA) schemes. A mathematical framework, which relies on method moments, is proposed statistically characterize end-to-end (e2e) these It shown that either Gamma distribution or Log-Normal can used approximate magnitude e2e channel coefficients in both With findings, evaluate performance schemes terms outage probability (OP) ergodic capacity (EC), tight closed-form expressions for OP EC derived. Representative results show ERA scheme outperforms ORA EC. addition, under i.n.i.d. fading channels, reflecting element settings location have significant impact