Non-Time-Switching Full-Duplex Relay System with SWIPT and Self-Energy Recycling

Adopting simultaneous wireless information and power transfer (SWIPT) technology to realize information and energy transmission based on radio frequency(RF) signals, a non-time-switching full-duplex relay system with SWIPT and self-energy recycling in radio frequency network is proposed. In this system, multiple idle wireless devices with energy are used as an additional energy access point (EAP), the energy-limited relay adopts the power splitting (PS) scheme, and information transmission, energy harvest and cooperative transmission are completed simultaneously in a slot. Taking maximize system throughput as an optimization target, the system transforms the original multivariate non-convex problem into a semi-definite programming problem by adopting quadratic optimization, semi-definite relaxation (SDR) and variable reduction methods, and utilizes Lagrange method to solve optimization problems. The system performance is improved by jointly optimizing the relay transmit power, the relay transmit beamforming vector and the power splitting ratio. Simulation experiments show that the throughput of the proposed system is better than the amplify-and-forward (AF) protocol under the decode-and-forward (DF) protocol. And when the energy harvested by the source node is limited, the stable and efficient operation of the system can be promoted by increasing the number of EAPs to increase the energy obtained by the system. Experimental results also verify that compared with half-duplex with SWIPT and full-duplex without SWIPT relay systems, the proposed system has more significant gains in improving system performance.