PhD Oral Exam - Damoon Shahbaztabar, Electrical and Computer Engineering

When studying for a doctoral degree (PhD), candidates submit a thesis that provides a critical review of the current state of knowledge of the thesis subject as well as the student’s own contributions to the subject. The distinguishing criterion of doctoral graduate research is a significant and original contribution to knowledge.

Once accepted, the candidate presents the thesis orally. This oral exam is open to the public.

Abstract

Reconfigurable intelligent surfaces (RISs) are expected to play an important role in future wireless networks by enabling programmable manipulation of the radio propagation environment. Their performance, however, is fundamentally influenced by statistical dependence arising from shared propagation paths, correlated channel components, finite-resolution phase control, and hardware-induced phase errors. Such dependence is particularly important in reliability-oriented performance analysis because the joint behavior of the underlying random variables, rather than their marginal statistics alone, determines quantities such as outage probability, diversity gain, achievable rate, and sensing performance. Nevertheless, much of the existing analytical literature relies on independence assumptions, linear correlation measures, or distributional approximations such as the central limit theorem and Gamma fitting. These approaches can be inadequate when the dependence is nonlinear, non-Gaussian, or tail-sensitive, especially in RIS-assisted systems involving cascaded channels and practical phase impairments. This thesis addresses this limitation by developing a unified copula-based framework for statistical characterization, performance analysis, and design of dependence-aware RIS-assisted wireless communication systems, thereby allowing complex dependence to be modeled without imposing restrictive assumptions on the underlying marginal distributions.