基于磁感应技术的地下传感网信道建模仿真

Channel Modeling and Simulation of Wireless Underground Sensor Networks Based on Magnetic Induction Technology

针对无线地下传感网(Wireless Underground Sensor Network,WUSN)电磁波通信中的信道高路径损耗、信道条件动态变化大和天线尺寸过大等问题,研究了磁感应线圈(Magnetic Induction,MI)在WUSN传输过程的信道特性影响,分析了谐变次偶源在土壤地层中的传输原理,通过传输等效电路图分析了土壤中线圈的极化方向与涡流损耗系数对信道模型的影响,考虑频率与距离的变化对信道特性的影响。通过选择有利于地下传输的器件,进行地下收发实验,对比实验所测得的结果与理论信道模型,分析并确定低频磁感应技术的系统理论模型与线圈在地下收发实验的结果是一致的。

Aiming at the problem of high path loss, huge dynamic changes of channel conditions and large antenna size of the electromagnetic wave communication channel in wireless underground sensor networks （WUSN）, the channel characteristics of magnetic induction （MI） in the process of WUSN transmission are studied and the transmission principle of harmonic source in soil strata is analyzed. The influence of the polarization direction of the coil and the eddy current loss coefficient on the channel model is analyzed by the transmission equivalent circuit diagram, and the influence of the change of the frequency and the distance on the channel characteristics is considered. Finally the devices that are in favor of the underground transmission are selected and underground receiving and dispatching experiment is carried out. By comparing the measured results with the theoretical channel model, the theoretical model of the low frequency magnetic induction technique is consistent with the experimental results.