  We analyze and optimize a wireless system with energy transfer in the
downlink and information transfer in the uplink, under quasi-static Nakagami-m
fading. We consider ultra-reliable communication scenarios representative of
the fifth-generation of wireless systems, with strict error and latency
requirements. The error probability and delay are investigated, and an
approximation for the former is given and validated through simulations. The
numerical results demonstrate that there are optimum numbers of channels uses
for both energy and information transfer for a given message length.
