  Reconfigurable intelligent surfaces (RIS) as an effective technique for
intelligently manipulating channel paths through reflection to serve desired
users. Full-duplex (FD) systems, enabling simultaneous transmission and
reception from a base station (BS), offer the theoretical advantage of doubled
spectrum efficiency. However, the presence of strong self-interference (SI) in
FD systems significantly degrades performance, which can be mitigated by
leveraging the capabilities of RIS. In this work, we consider joint BS and RIS
beamforming for maximizing the downlink (DL) transmission rate while
guaranteeing uplink (UL) rate requirement. We propose an FD-RIS beamforming
(FRIS) scheme by adopting penalty convex-concave programming. Simulation
results demonstrate the UL/DL rate improvements achieved by considering various
levels of imperfect CSI. The proposed FRIS scheme validates their effectiveness
across different RIS deployments and RIS/BS configurations. FRIS has achieved
the highest rate compared to the other approximation method, conventional
beamforming techniques, HD systems, and deployment without RIS.
