  Energy harvesting technique is a potential way for relay node energy supply
in cooperative networks in terms of deployment flexibility and maintain charge
reduction. Unlike traditional power source, relay node in this case may run out
of energy with certain probability, which can degrade the benefit from
relay-aided cooperative transmission. In this paper, we concentrate on the
outage behavior of cooperative networks aided by energy harvesting relay node
in slow fading channel, and attempt to derive the closed-form expression of
outage probability of proposed cooperative protocol. Compared with traditional
direct transmission protocol, two conclusions are derived: 1) the diversity
gain cannot be increased excepting the extreme case that energy-exhausted
probability is zero; 2) a multiplicative gain for improving system performance
can be obtained in terms of minimizing outage probability.
