Executive Summary
This thesis investigates the performance of acoustic spread-spectrum signaling in simulated ocean channels, focusing on Direct-Sequence Spread Spectrum (DSSS) modulation for undersea acoustic networking. It evaluates subspace-decomposition blind-equalization algorithms as alternatives to RAKE processing, tailored for superior performance in time-dispersive and frequency-dispersive ocean channels. The study uses Matlab implementations and Monte Carlo simulations to assess receiver performance, presenting bit-error rates versus signal-to-noise ratio under various conditions.
Why It Matters
This document is crucial for defense analysts as it details advancements in secure and robust underwater acoustic communication, a critical enabler for network-centric warfare and unmanned underwater vehicle operations. Improved underwater networking directly impacts naval operational capabilities and strategic advantage in contested maritime environments.
Key Takeaways
- DSSS modulation is a robust physical-layer basis for undersea acoustic networking, offering channel tolerance, transmission security, and multi-user access.
- Subspace-decomposition blind-equalization algorithms provide superior performance in time-dispersive and frequency-dispersive ocean channels compared to traditional RAKE processing.
- The developed methodology, using Matlab and Monte Carlo simulations, demonstrates that a Bit-Error Rate (BER) of 10^-5 is achievable, even in severe channel conditions at lower bit-rates.
Strategic Relevance
Reliable and secure underwater communication is a cornerstone of modern naval operations, enabling network-centric warfare, submarine communications, and control of Unmanned Underwater Vehicles (UUVs). This research directly contributes to enhancing the robustness and performance of such systems, providing a critical advantage in undersea domain awareness and control.