Research On Resource Allocation Optimization Algorithm For Simultaneous Wireless Information And Energy Transfer In Wireless Relay Networks

Wireless relay is considered as a key technology at wireless communication network, which enable to effectually enlarge the coverage of wireless communication area and take advantage of cooperation diversity at a low cost. In this paper, based on the technology of simultaneous wireless information and power transfer(SWIPT), a resource allocation optimization algorithm is proposed, which in use of the power separation receiver on the relay to collect the RF signal. The optimization algorithm is proposed in order to maximize the end-to-end system rate. Due to the existence of non-convex relay energy constraints, the resource allocation optimization problem for SWIPT is a non-convex problem. In this paper, through variable substitution, we convert the non-convex resource allocation optimization problem into convex problem on the amplify-and-forward(AF) relay system and the decode-and-forward(DF) relay system respectively. According to this, we finally get the optimal resource allocation algorithm by solving the convex problems. The simulation result shows that compared with the fixed energy scheme of the power split relay, the optimal resource allocation algorithm that proposed in this paper can significantly improve the end-to-end system achievable rate. Based on the optimal resource allocation algorithm on single relay, we further propose a multiple relay selection strategy, the Genetic Algorithm(GA), in order to optimal the relay network performance. Multiple relay cooperate communication, which is a scheme that take advantage of the diversity andthe equal-gain combining technology to improve the system performance of the wireless relays network. In this paper, we give a multiple relay selection optimal strategy in use of genetic algorithm to maximize the system received SNR, which based on multiple parallel two-hop relay systems. The simulation result shows that the system achievable rate and the system stability improve significantly by using the combined optimal scheme of single relay optimal resource allocation algorithm and multiple relay selection strategy in genetic algorithm.