Joint power allocation for MIMO-OFDM communication with full-duplex relaying

We address the problem of joint power allocation in a two-hop MIMO-OFDM link where a source node sends data to a destination node via an amplify-and-forward relay. Since the relay operates in the full-duplex mode, it receives and forwards data simultaneously. Our design objective is to maximize the end-to-end throughput, subject to either the joint sum-power constraint of both the source and the relay or the individual sum-power constraints at the source and the relay. The formulated problems are large-scale nonconvex optimization problems, for which efficient and optimal solutions are not available. Using the successive convex optimization approach, we develop a novel iterative algorithm of extremely low complexity that is especially suitable for large-scale computation. In each iteration, a simple closed-form solution is derived for the approximated convex program. The proposed algorithm is proved to always converge to at least a local optimum of the original nonconvex problems. Numerical results confirm that the devised algorithm converges quickly, and that our optimal power allocation solutions help realize the potential throughput gain of MIMO-OFDM full-duplex relaying over the conventional half-duplex relaying strategy.