  In this paper, a cooperative communication network based on energy-harvesting
(EH) decode-and-forward (DF) relays that harvest energy from the ambience using
buffers with harvest-store-use (HSU) architecture is considered. An
opportunistic routing (OR) protocol, which selects the transmission path of
packet based on the node transmission priority, is proposed to improve data
delivery in this network. Additionally, an algorithm based on state transition
matrix (STM) is proposed to obtain the probability distribution of the
candidate broadcast node set. Based on the probability distribution, the
existence conditions and the theoretical expressions for the limiting
distribution of energy in energy buffers using discrete-time continuous-state
space Markov chain (DCSMC) model are derived. Furthermore, the closed-form
expressions for network outage probability and throughput are obtained with the
help of the limiting distributions of energy stored in buffers. Numerous
experiments have been performed to validate the derived theoretical
expressions.
