%A CHI Kai-kai, ZHU Liu-shuan, CHENG Zhen and TIAN Xian-zhong %T Minimal Energy Transmitters Placement Approaches for RF-energy Harvesting Heterogeneous Wireless Sensor Networks %0 Journal Article %D 2017 %J Computer Science %R 10.11896/j.issn.1002-137X.2017.01.027 %P 140-144 %V 44 %N 1 %U {https://www.jsjkx.com/CN/abstract/article_1016.shtml} %8 2018-11-13 %X The applications of battery-powered wireless sensor networks are greatly restricted by the inconvenient or even impossible battery replacement.This paper considered the RF-energy harvesting heterogeneous wireless sensor networks where different sensor nodes may have different requirements on the power output of energy harvesting,and studied how to place the energy transmitters (ETs) so that the power output requirements of all nodes are satisfied and the number of ETs is minimized at the same time.This paper first formulated this ETs placement problem so as to deeply and theoretically understand this problem,and then presented a low-complexity greedy scheme and a particle swarm optimization (PSO)-based scheme with relatively high complexity.Simulation results demonstrate that,compared to the greedy scheme,the PSO-based scheme is able to slightly reduce the average number of ETs.However,as the PSO-based scheme is with relatively high complexity,it can be used for the scenarios with not many nodes,whereas the greedy scheme can be used for the scenarios with a large number of nodes.