  This work demonstrates the effectiveness of a novel simultaneous transmission
and reflection reconfigurable intelligent surface (STAR-RIS) in Full-Duplex
(FD) aided communication system. The objective is to minimize the total
transmit power by jointly designing the transmit power and the transmitting and
reflecting (T&R) coefficients of the STAR-RIS. To solve the nonconvex problem,
an efficient algorithm is proposed by utilizing the alternating optimization
framework to iteratively optimize variables. Specifically, in each iteration,
we drive the closed-form expression for the optimal power design. The
successive convex approximation (SCA) method and semidefinite program (SDP) are
used to solve the passive beamforming optimization problem. Numerical results
verify the convergence and effectiveness of the proposed algorithm, and further
reveal in which scenarios STAR-RIS assisted FD communication defeats the
Half-Duplex and conventional RIS.
