  We consider a dual-hop full-duplex relaying system, where the energy
constrained relay node is powered by radio frequency signals from the source
using the time-switching architecture, both the amplify-and-forward and
decode-and-forward relaying protocols are studied. Specifically, we provide an
analytical characterization of the achievable throughput of three different
communication modes, namely, instantaneous transmission, delay-constrained
transmission, and delay tolerant transmission. In addition, the optimal time
split is studied for different transmission modes. Our results reveal that,
when the time split is optimized, the full-duplex relaying could substantially
boost the system throughput compared to the conventional half-duplex relaying
architecture for all three transmission modes. In addition, it is shown that
the instantaneous transmission mode attains the highest throughput. However,
compared to the delay-constrained transmission mode, the throughput gap is
rather small. Unlike the instantaneous time split optimization which requires
instantaneous channel state information, the optimal time split in the
delay-constrained transmission mode depends only on the statistics of the
channel, hence, is suitable for practical implementations.
