射频供能传感网能量源移动路径约束下时延最小化供电方案

Charging Time Minimized Charging Schemes for RF-powered Sensor Network with Moving Trajectory Constrained Mobile Energy Transmitter

射频能量捕获技术是解决传统无线传感网由于节点电量有限而生命周期受限的有效方法。现有的射频能量源移动供电方案中,能量源可以无限制地沿任何方向行进到网络区域内的任一位置来给节点供电。然而在现实场景中,能量源通常只能沿着既有道路行进。考虑能量源行进路径约束下的供电总时延最小化问题,分别提出全程移动供电方案和部分位置停留供电方案,并提出高效算法来确定这两个方案的最佳行进路径和供电时间。仿真结果表明,两种方案的供电总时延均显著优于转折点供电基准方案。相比于部分位置停留供电方案,全程移动供电方案的计算复杂度较低,但供电总时延更长一些。

Radio-Frequency （RF） energy harvesting technique is proved a promising way to solve the short network lifetime issue of traditional Wireless Sensor Networks （WSNs） caused by sensors＇ finite energy. In the existing charging schemes using the mobile RF Energy Transmitter （ET）, ET can move to any location along any moving direction in the monitoring area for energy provision. However, in the practical scenario, ET can only move along the existing roads. For the first time, the charging time minimization issue is considered under the moving trajectory constraint. The Mobile Charging （MC） scheme where ET transmits RF energy while moving and the Static Charging （SC） scheme where ET transmits RF energy while unmoving are proposed, whose the moving trajectory and energy provision time are optimized by the proposed efficient algorithms. Simulation results reveal that the total charging delay of proposed schemes is smaller than the baseline scheme of transmitting energy at turning points. The MC scheme has lower computational complexity but has a slightly larger charging delay as compared to the SC scheme.