Full Duplex-ing over Two Hops under Full Interference

In this paper, we study the optimization of transmission power in a two hop in-band full-duplex (IBFD) relaying scenario under full interference, i.e., when the source and destination nodes hear each other, which is highly likely in cellular or dense wireless networks. Considering imperfect self interference (SI) cancellation for IBM operation at the relay node, we propose closed form solutions for calculating the power levels for the simultaneously transmitting nodes in an effort to achieve the maximum end-to-end throughput, and we derive an optimal power assignment policy. We compare the end-to-end throughput performance of IBFD relaying with proposed power assignment to that of traditional half-duplex (HD) relaying. Our results show the efficacy of power control for IBFD relaying, and show that the amount of performance improvement over traditional HD relaying depends on the level of SI suppression. More specifically, IBFD relaying has shown to be superior to HD relaying by up to 50% in the investigated scenarios.