  This paper studies the performance of a differential chaos shift keying
(DCSK)-based wireless power transfer (WPT) setup in a frequency selective
scenario. Particularly, by taking into account the nonlinearities of the energy
harvesting (EH) process and a generalized frequency selective Nakagami-m fading
channel, we derive closed-form analytical expressions for the harvested energy
in terms of the transmitted waveform and channel parameters. A simplified
closed-form expression for the harvested energy is also obtained for a
scenario, where the delay spread is negligible in comparison to the transmit
symbol duration. Nontrivial design insights are provided, where it is shown how
the power delay profile of the channel as well as the parameters of the
transmitted waveform affect the EH performance. Our results show that a
frequency selective channel is comparatively more beneficial for WPT compared
to a flat fading scenario. However, a significant delay spread negatively
impacts the energy transfer.
