Use of magnetic fields (MFs) for underwater wireless communication is very promising nowadays due to its advantages such as low power, low cost, no multipath, no Doppler effect, and instant communication. Considering the importance and potential of MF communication for underwater wireless sensor networks, this article presents a review on the fundamental concepts and theory of MF communication by identifying the main blocks, describing the limitation of each block and mentioning the advancements being done. The three fundamental blocks identified are: 1) the transmit and receive coils; 2) the matching network; and 3) the channel characteristics of the MFs. The first block explains how a single-dimensional coil is used to establish a directional communication link between a transmitter and a receiver and then the method by which the directionality problem is solved using multidimensional coils and metamaterial coils. Furthermore, the matching network explains the difference between the induction and resonance phenomena and their effect on the range and capacity. In the third block, the factors affecting the MFs are mentioned, which are critical to underwater wireless communication with MFs. Finally, this article introduces the recent advancements at the physical, MAC, and network layers.

中文翻译：

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水下无线传感器网络磁场通信的基础知识和进展


利用磁场（MF）进行水下无线通信具有低功耗、低成本、无多径、无多普勒效应和即时通信等优点，目前非常有前景。考虑到 MF 通信对于水下无线传感器网络的重要性和潜力，本文通过识别主要模块、描述每个模块的局限性并提及正在取得的进展，对 MF 通信的基本概念和理论进行了回顾。确定的三个基本模块是：1）发射和接收线圈； 2）匹配网络； 3) MF的信道特性。第一个块解释了如何使用单维线圈在发射器和接收器之间建立定向通信链路，然后解释使用多维线圈和超材料线圈解决方向性问题的方法。此外，匹配网络解释了感应和谐振现象之间的差异及其对范围和容量的影响。在第三块中，提到了影响MF的因素，这些因素对于MF的水下无线通信至关重要。最后，本文介绍了物理层、MAC 层和网络层的最新进展。