Outage Analysis and Optimization in Single- and Multiuser Wireless Energy Harvesting Networks

Compared to battery-powered wireless nodes having a constant but limited power supply, wireless nodes having energy harvesting (EH) capability may greatly prolong the network's sustainability. However, the energy usage policies (EUPs) have to be carefully designed according to the characteristics of the random power supply gleaned from the environment. In this paper, we carry out the outage analysis of a point-to-point (P2P) network relying on an EH transmitter, which has a finite energy buffer (EB) for transmission over a fading channel when having random energy arrival rates. A discrete Markov chain (DMC) model is proposed for characterizing the energy state of the EB, which is then used for quantifying the outage probability (OP) over the fading channels. Then, we propose both a novel 2-D and a low-complexity 1-D search algorithm for finding the specific EUPs, which are capable of minimizing the OP for the P2P network considered. It is shown that the EUP found by both algorithms outperforms the state-of-the-art EUPs disseminated in the open literature. Furthermore, we consider a multiple-access network having
$M$
EH-aided sources, where we propose a distributed EUP optimization (DEUPO) algorithm and then minimize the OP relying on the local optimization of each EH-aided source.