Iterative Dynamic Power Splitting for Multi-relay Networks with Wireless Energy Harvesting

Wireless energy harvesting has attracted a lot of attention in relay networks, where each relay node can use its harvested energy from the received radio frequency (RF) signals to forward messages. In this letter, we consider a multi-relay system and study the problem on how each relay splits the power of its received RF signal to maximize the information signal-to-noise ratio (SNR) at the destination node. As this problem is non-convex and difficult to be solved, we propose an iterative dynamic power splitting algorithm based on analyzing the first order necessary condition of the optimal solution. Besides, the convergence, initial value and transmission protocol of the proposed algorithm are also discussed. Simulation results show that the proposed iterative power splitting algorithm has nearly the same performance as the optimal exhaustive search and outperforms fixed power splitting schemes.