  Statistical characterization of the signal-to-noise ratio (SNR) of
reconfigurable intelligent surface (RIS)-assistedcommunications in the presence
of phase noise is an important open issue. In this letter, we exploit the
concept of copula modeling to capture the non-standard dependence features that
appear due to the presence of discrete phase noise. In particular,we consider
the outage probability of RIS systems in Rayleighfading channels and provide
joint distributions to characterize the dependencies due to the use of finite
resolution phase shifters at the RIS. Numerical assessments confirm the
validity of closed-form expressions of the outage probability and motivate the
use of bivariate copula for further RIS studies.
