Relay Selection for Radio Frequency Energy-Harvesting Wireless Body Area Network With Buffer

In this paper, a relay selection protocol for energy harvesting wireless body area network with buffer is proposed, that considers both the energy of relay nodes and channel state information. The relay node harvests energy from the received radio-frequency signals, then the relay node consumes the harvested energy to transmit information to the destination node. In the proposed relay selection protocol, the relay with the most energy is selected to receive information, the relay with the best relay-destination channel is selected from candidate relays for transmission. The proposed protocol can mitigate the risk of inappropriate relay selection due to channel mismatch problem and avoid the overuse of the same relay. The outage probability is used to measure the system performance. We investigate the outage probability of the optimal relay selection protocol in the time switching and power splitting schemes, respectively. Numerical results show that the proposed protocol significantly outperforms conventional relay selection protocols.