Joint Time Allocation and Power Splitting Schemes for DF Energy Harvesting Relaying Networks

In this paper, a joint time allocation and power splitting (JTAPS) scheme is considered for the decode-and-forward (DF) energy harvesting (EH) relaying network, where the "harvest-then-forward" strategy is employed. We focus on designing an optimal JTAPS scheme to conduct the relay under statistical/instantaneous channel state information (CSI) in terms of outage performance. For the statistical CSI, the expressions of the outage probability and outage capacity are derived to determine the optimal power splitting (PS) ratio and time allocation (TA) ratio. For the instantaneous CSI, a joint PS ratio and TA ratio optimization problem is formulated to minimize the outage probability. Considering that the optimization problem is non-convex, a split-step iterative method is proposed to obtain the optimal PS ratio and TA ratio. Finally, simulation results are given to illustrate the advantage of JTAPS scheme with respect to the outage performance.