A Destination-Aided Wireless Energy Transfer Scheme in Multi-Antenna Relay Sensor Networks

Abstract

We propose a destination-aided wireless energy transfer scheme in wireless relay sensor networks, where the power of the information collector who has stable power supply is fully exploited. Specifically, a multi-antenna three-node (S, R, D) relay system is considered, where the energy-constrained node R (sensor) assists to forward the message from S (sensor) to D (information collector), and also reports its own sensing information to D. To enhance the amount of scavenged energy at R, the strong energy stream is first transferred by D. The transmitter beamformers, receiver vectors and the relay processing matrix are jointly optimized to maximize the rate of R subject to the required rate of S and the power constraints. To solve this non-convex problem efficiently, these variables are alternatively optimized. Numerical results show that our proposed scheme greatly improves the capacity region, especially when the relay is close to the destination.