A Multicarrier Underwater Acoustic Modem with Precise-Ranging Capability

具有精确测距能力的多载波水声调制解调器

• 批准号: 0725562
• 负责人: Shengli Zhou
• 金额: $ 27.4万
• 依托单位: University of Connecticut
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2009-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0725562&HistoricalAwards=false
• 关键词: Multicarrier; Underwater; Acoustic; Modem; Precise

Intellectual Merit: This project investigates a paradigm shift in acoustic underwater communication from single-carrier transmission to multi-carrier modulation in the form of orthogonal frequency division multiplexing (OFDM). OFDM has its unique strength in handling high-rate transmissions over long dispersive channels and has prevailed in recent broadband wireless radio applications. However, underwater acoustic channels are far more challenging than their radio counterparts due to their large bandwidth-to-carrier-frequency ratio, large propagation delay, large multipath spread, and fast channel variations. Incorporating the unique characteristics of underwater acoustic channels, our first task is to make OFDM work in underwater environments with fast-moving platforms. Preliminary experimental results have demonstrated the effectiveness of our proposed approach even when the relative speed between the transmitter and the receiver is up to 10 knots, which is the current state of the art. In our second task, we equip the multi-carrier modem with precise-ranging capability. The key is to develop precise synchronization algorithms that can locate the "first arrival" in the presence of dense multi-path conditions and that can work well in fast-varying underwater channels. In our third task, we develop a standalone modem prototype based on a digital signal processor that integrates the transceiver algorithms developed in this project.Broader Impact: Providing a multi-carrier acoustic modem with ranging capability, this project has the potential to directly benefit the development of underwater wireless sensor networks for a variety of applications. Due to the large bandwidth-to-carrier-frequency ratio of underwater acoustic channels, the proposed methodology and algorithms may, also, have an impact on wideband and ultra-wideband radio applications. This project integrates research and education to enhance the content of undergraduate and graduate classes and, in particular, provides innovative senior design projects.

智力优点：该项目调查了声学水下通信从单载波传输到多载体调制的范式转移，以正交频施加多元化的形式（OFDM）。 OFDM在处理长期分散通道的高速传输方面具有独特的力量，并且在最近的宽带无线无线电应用中占了上风。 然而，由于其较大的带宽频率比率，大传播延迟，较大的多径扩散和快速通道变化，水下声通道比无线电频道更具挑战性。 结合了水下声学通道的独特特征，我们的首要任务是使OFDM在具有快速移动平台的水下环境中工作。 初步实验结果表明，即使发射器和接收器之间的相对速度最高10节，这是最新的，即使是最新的，我们提出的方法的有效性也是如此。 在第二个任务中，我们为多载体调制解调器配备了精确的功能。 关键是要开发精确的同步算法，这些算法可以在存在密集的多路径条件下定位“首次到达”，并且可以在快速变化的水下通道中运行良好。 在我们的第三个任务中，我们基于数字信号处理器开发独立的调制解调器原型，该原型集成了该项目中开发的收发器算法。Broader的影响：提供具有范围功能的多载波声学调制解调器，该项目有可能直接受益于各种应用程序的无线传感器网络的开发。 由于水下声学通道的带宽与频率频率比率很高，因此所提出的方法论和算法也可能对宽带和超宽带无线电应用产生影响。 该项目集成了研究和教育，以增强本科和研究生班的内容，尤其是提供创新的高级设计项目。