  Energy-harvesting and wireless power transfer in cooperative relaying
networks have recently attracted a considerable amount of research attention.
Most of the existing work on this topic however focuses on Rayleigh fading
channels which represents outdoor environments. Unlike these studies, in this
paper we analyze the performance of wireless power transfer in two-hop
decode-and-forward (DF) cooperative relaying systems in indoor channels
characterized by log-normal fading. Three well-known energy-harvesting
protocols are considered in our evaluations: a) time-switching relaying (TSR),
b) power-splitting relaying (PSR) and c) ideal relaying receiver (IRR). The
performance is evaluated in terms of the ergodic outage probability for which
we derive accurate analytical expressions for the three systems under
consideration. Results reveal that careful selection of the energy-harvesting
time and power-splitting factors in the TSR- and PSR-based system are important
to optimize performance. It is also presented that the optimized PSR system has
near-ideal performance and that increasing the source transmit power and/or the
energy-harvester efficiency can further improve performance.
