  Willems' fundamental lemma and system level synthesis both characterize a
linear dynamic system by its input/output sequences. In this work, we extend
the application of the fundamental lemma from deterministic to uncertain LTI
systems and then further prove this extension to be equivalent to system level
synthesis. Based on this uncertain extension, a robust closed-loop data-enabled
predictive control scheme is proposed, where a causal feedback control law is
further derived. Two numerical experiments, including the temperature control
of a single-zone building, are carried out to validate the effectiveness of the
proposed data-driven controller.
