Optimal resource allocation in wireless relay networks with SWIET

Simultaneous wireless information and energy transfer (SWIET) is a promising energy harvesting (EH) technique to power energy-constrained wireless nodes in wireless communications. In wireless relay networks, employing SWIET at the source-to-relay link, an energy-constrained relay node can harvest energy from the radio-frequency (RF) signals transmitted by a source node while assisting information relaying, and thus its lifetime can be prolonged. This paper investigate the resource allocation in a SWIET-based two-hop amply-and-forward or decode-and-forward relay network with a power-splitting EH receiver at the relay. The goal is to maximize the end-to-end achievable rate. Firstly, this paper formulate the resource allocation problem as a non-convex optimization problem. Then, this paper transform the non-convex problem into a convex problem by algebraic transformations. By solving the convex problem, this paper obtain the optimal resource allocation policy for the AF or DF relay network. Simulation results verify the optimality of the proposed resource allocation policy in this paper.