SGER: Algorithms and Architectures for Low Cost High Data Rate Acoustic Modems

集成、混合和复杂系统Iltis加州大学圣巴巴拉分校SGER：低成本高数据速率声学调制解调器的算法和架构知识产权：新的和正在进行的海洋科学项目，包括长期生态研究（LTER）网站和海洋观测站倡议对低成本，开放式架构的水下网络声学调制解调器有多种需求。 这项探索性的研究确定了单载波频域均衡（SC-FDE）是否是高速、长距离声学通信中正交频分复用（OFDM）的可行替代方案。 SC-FDE在较低的功率变化和较低的复杂度编码要求方面具有优于OFDM的潜在显著优势。 由于水声信道具有长、稀疏的多径特性和快速的时变特性（多普勒扩展），水声信道对通信系统设计者具有挑战性。 一个强大的匹配追踪（MP）信道估计器，以前开发的较低的数据速率直接序列声学调制解调器的调查人员，在这里应用到SC-FDE和OFDM。 并排比较，以确定是否SC-FDE是可行的，在水下信道，如果它的功率和复杂度优势，OFDM在声学制度。 SC-FDE和OFDM都需要纠错编码来在长距离声学信道上通信。 新的迭代解码和信道估计技术相结合的匹配追踪和卷积编码的实时实现进行了研究。 现有的测试平台用于评估SC-FDE和OFDM调制解调器的性能。更广泛的影响：实时声学通信是广泛的海洋科学和生态研究项目所需要的。 这项研究的结果可能是为海洋学研究人员提供现成的声学网络的重要的第一步。 水下网络所促成的研究可对我们理解海底物理环境与海洋生物之间的相互作用产生广泛影响，包括世界各地珊瑚礁健康的关键问题。 该项目还为海洋科学、信号处理和网络研究的研究生提供交叉培训。

Integrative, Hybrid and Complex SystemsRonald A. IltisUniversity of California-Santa BarbaraSGER: Algorithms and Architectures for Low Cost High Data Rate Acoustic ModemsIntellectual Merit: New and ongoing ocean sciences projects, including Long-Term Ecological Research (LTER) sites and the Ocean Observatories Initiative have multiple needs for low-cost, open architecture acoustic modems for underwater networking. This exploratory research determines if single-carrier frequency domain equalization (SC-FDE) is a viable alternative to orthogonal frequency-division multiplexing (OFDM) for high-speed, longer range acoustic communications. SC-FDE has potentially significant advantages over OFDM in terms of lower power variation and lower-complexity coding requirements. The underwater acoustic channel is challenging to the communication systems designer due to its long, sparse multipath characteristics and rapid time-variation (Doppler spread). A robust Matching Pursuits (MP) channel estimator, previously developed for lower data rate direct-sequence acoustic modems by the investigators, is applied here to both SC-FDE and OFDM. Side-by-side comparisons are performed to determine if SC-FDE is feasible in the underwater channel and if its power and complexity advantages over OFDM hold in the acoustic regime. Both SC-FDE and OFDM require error correction coding to communicate over the long range acoustic channel. New iterative decoding and channel estimation techniques combining Matching Pursuits and convolutional coding are investigated for real-time implementation. Existing testbeds are used to evaluate SC-FDE and OFDM modem performance.Broader Impact: Real-time acoustic communications is required for a broad range of ocean sciences and ecological research projects. The results of this research could be an important first step to off-the-shelf availability of acoustic networking for oceanographic researchers. Research enabled by underwater networking can have broad impacts on our understanding of interactions between the physical undersea environment and marine life, including the critical question of health of coral reefs worldwide. This project also provides cross-training to graduate students in ocean sciences, signal processing and networking research.