针对研究磁感应在无线地下传感网(Wireless Underground Sensor Network,WUSN)土壤传输过程的信道特性,首先对磁感应技术的核心谐变磁偶源进行模型推导,推导出谐变磁偶源在近场区的分布概况,在此基础上得出谐变磁偶源在地下土壤介质中的传输特性,然后通过理论分析磁感应线圈的信道模型,建立随各个参数变化的信号感应模型,确定了基于各影响因子的路径损耗变化情况。最终通过选择有利于地下传输的低功耗、低频率器件,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,分析并确定了低频磁感应技术的系统理论模型适合于线圈在地下土壤中所做的实验。
Aiming at the research of channel characteristics of magnetic induction in wireless underground sensor networks(WUSN) soil transmission, first of all, the core of harmonic variable magnetic dipole source model is derived for time-homonic magnetic dipole source in the near-field region probability distribution condition to get the transmission characteristics in subsurface soil medium. Then through theoretical analysis of magnetic induction coil of the channel model, the changes of all the parameters of the induction signal model are established to determine the consumption based on variations in path loss of each influencing factor. Finally, by choosing devices with low power consumption and low frequency for underground transmission, the underground transceiver experiment is conducted to compare the measured results and the theoretical channel model, and shows that the system theory model in low frequency magnetic induction is fit to coil in subsurface soil.