Relay Selection Based on Simultaneous Wireless Information and Power Transfer for Wireless Sensor Networks

Simultaneous wireless information and power transfer (SWIPT) is a promising new solution to provide a perpetual lifetime for energy constrained nodes in wireless networks. In this paper, we consider a wireless sensor relay network, where relay nodes forward a radio frequency (RF) signal from a source node to a destination node by first harvesting energy from the RF signal. For multiple relay nodes, the relay that is preferred for information transmission does not necessarily coincide with the relay that has the maximum harvested energy. We propose relay selection schemes in order to obtain the best rate performance in the relaying SWIPT system. We derive analytic expressions for the outage probability in the delaylimited transmission mode with our relay selection schemes. The simulation results show that the throughput of the system increases as the number of relay nodes increase.