Distributed Electro-Mechanical Transmitters for Adaptive and Power-Efficient Wireless Communications in RF-Denied Environments

分布式机电发射器，用于射频干扰环境中的自适应和高能效无线通信

基本信息

批准号：
1905434
负责人：
Seungdeog Choi
金额：
$ 15万
依托单位：
Mississippi State University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2019
资助国家：
美国
起止时间：
2019-07-01 至 2023-06-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1905434&HistoricalAwards=false
关键词：
Distributed Electro Mechanical Transmitters Adaptive

项目摘要

Propagation of radio frequency (RF) electromagnetic waves becomes infeasible in certain situations, thus resulting in "RF-denied" environments. Examples include underground and deep-water facilities (mines, shelters, storage areas, tunnels, submarines, undersea cables, etc.). Recent events have highlighted the importance of wireless communications with such environments. A prominent example is the July 2018 rescue of a soccer team from the Tham Luang Nang Non cave in Thailand after they had been trapped underground for over two weeks. Such RF-denied environments are fundamentally produced by the short "skin depth" of electromagnetic waves within conductive media such as earth or seawater, which results in high attenuation. Fortunately, the skin depth increases as the frequency decreases, so extremely low frequency (ELF) radio waves in the kHz range can penetrate long distances in nominally RF-denied environments. For example, the skin depth in sea water is 7.1 m at 1 kHz, which would allow undersea communications to depths of about 30 m with reasonable transmit power levels if one could effectively couple ELF radio waves into the medium. However, conventional antennas are extremely large and impossible to deploy in this frequency range, while electrically-short antennas have very poor power efficiency. This project seeks to solve this fundamental problem by adopting a radically new approach to ELF antennas that is based on the mechanical motion of permanent magnets. The proposed research will have a broad impact on the availability of bidirectional wireless communications in RF-denied environments. Specifically, it will enable low-data-rate wireless links to be established using portable, robust, low-power, and low-cost devices. Such links are expected to have a multitude of applications in fields such as sensing and networking in underwater or underground environments, near-surface geophysics, atmospheric science, search and rescue operations, mining, and oil and gas exploration.The availability of portable low-power ELF transceivers would immediately enable communications within RF-denied environments by enabling bidirectional low-data-rate wireless links with the surface. While miniaturized and highly-sensitive ELF receivers are available, ELF transmitters (typically dipole or loop antennas) are the key obstacles for realizing such links since they are physically large and power-hungry. Thus, this project focuses on miniaturized and power-efficient ELF transmitters that enable bidirectional communications over short- and medium-range (up to about 1 km) wireless links in conductive media. In particular, the proposed research will explore a fundamentally new all-mechanical approach to ELF transmitter design that has the potential to enable efficient use of this region of the EM spectrum. The major intellectual contributions of this project focus on different aspects of this overall approach. They include: i) Proposing the concept of distributed all-mechanical transmitters based on synchronization over either wired or wireless networks and showing how it overcomes the key limitations of existing ELF transmitter architectures; ii) Creating a theoretical basis for the design of power-efficient wireless communications using systems that have significant mechanical inertia, thus linking the mathematics of information transfer over fading channels to the physics of the mechanical devices; and iii) Laying the first theoretical groundwork for the precise control of networked high-speed machines, which has the potential to dramatically advance the current state of the art by seamlessly modeling complex 3-D (dimensional) machine parameter variations and their tight coupling with high-speed machine vibrations and energy/power fluctuations within the transmitter network.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

在某些情况下，射频（RF）电磁波的传播变得不可行，从而导致“ RF贬低”的环境。例子包括地下和深水设施（矿山，庇护所，储藏区，隧道，潜艇，海底电缆等）。最近的事件强调了与此类环境无线通信的重要性。一个重要的例子是2018年7月从泰国的Tham Luang Nang Non Cave救出了一支足球队后，他们被困在地下两周以上。这样的RF贬低的环境从根本上是由导电介质（例如地球或海水）内电磁波的短“皮肤深度”产生的，这会导致衰减较高。幸运的是，随着频率的降低，皮肤深度的增加，因此，在名义上被RF受否认的环境中，KHz范围内极低的频率（ELF）无线电波可以穿透长距离。例如，在1 kHz时，海水的皮肤深度为7.1 m，如果可以有效地将精灵无线电波稍微将Elf Radio Wave插入培养基，则可以使海底通信达到约30 m的深度。但是，传统的天线非常大，无法在此频率范围内部署，而电动天线的功率效率很差。该项目旨在通过基于永久磁铁的机械运动来采用一种彻底的精灵天线方法来解决这个基本问题。拟议的研究将对在RF受否决的环境中的双向无线通信的可用性产生广泛的影响。具体而言，它将使低数据速率无线链接使用便携式，健壮，低功率和低成本设备建立。 Such links are expected to have a multitude of applications in fields such as sensing and networking in underwater or underground environments, near-surface geophysics, atmospheric science, search and rescue operations, mining, and oil and gas exploration.The availability of portable low-power ELF transceivers would immediately enable communications within RF-denied environments by enabling bidirectional low-data-rate wireless links with the surface.尽管可以使用微型和高度敏感的小精灵接收器，但精灵发射器（通常是偶极子或环形天线）是实现此类链接的关键障碍，因为它们在物理上是大型且渴望的。因此，该项目着重于微型和发电的精灵发射器，这些发射器可以通过导电媒体中的短和中端（约1 km）无线链路进行双向通信。尤其是，拟议的研究将探索一种从根本上开始的全机械方法，用于精灵发射器设计，该方法有可能有效利用EM谱系的该区域。该项目的主要智力贡献集中于这种整体方法的不同方面。它们包括：i）基于有线或无线网络的同步，提出分布式全机械发射机的概念，并显示其如何克服现有精灵发射机体系结构的关键局限性； ii）为使用具有重要机械惯性的系统设计了功率高效的无线通信的理论基础，从而将信息传输的数学通过褪色渠道链接到机械设备的物理学；和iii）为精确控制网络高速机器的第一个理论基础，这有可能通过无缝建模复杂的3-D（维）机器参数变化及其与高速机器的振动和能量/功率的启动nsf的传递nsf nsf partos and nsf partosef and nsf the ns nsf pertosef and n s n s n s n s nsf and nsf and ns nsf shos n s nsf and nsf and nsf and n s n s n s n s n s n s.使用基金会的智力优点和更广泛的影响评估标准进行评估。