Undersea Acoustic Propagation Channel Estimation

Abstract

This research concerns the continuing development of Seaweb underwater networking. In this type of wireless network the radio channel is replaced by an underwater acoustic channel which is strongly dependent on the physical properties of the ocean medium and its boundaries, the link geometry and the ambient noise. Traditional acoustic communications have involved a priori matching of the signaling parameters (e.g., frequency band, source level, modulation type, coding pulse length) to the expected characteristics of the channel. To achieve more robust communications among the nodes of the acoustic network, as well as high quality of service, it is necessary to develop a type of adaptive modulation in the acoustic network. Part of this process involves estimating the channel scattering function in terms of impulse response, the Doppler effects, and the link margin. That is possible with the use of a known probe signal for analyzing the response of the channel. The estimated channel scattering function can indicate the optimum signaling parameters for the link (adaptive modulation). This approach is also effective for time varying channels, including links between mobile nodes (e.g. two submarines), since the channel characteristics can be updated each time we send a probe signal.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 2005
Accession Number
ADA435483

Entities

People

  • Spyridon Dessalermos

Organizations

  • Naval Postgraduate School

Tags

Communities of Interest

  • Energy and Power Technologies
  • Ground and Sea Platforms
  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Acoustic Channels
  • Acoustic Communications
  • Acoustic Waves
  • Acoustics
  • Ambient Noise
  • Communication Channels
  • Communication Systems
  • Data Transmission
  • Doppler Effect
  • Frequency
  • Frequency Bands
  • Frequency Shift
  • Geometry
  • Repetition Rate
  • Scattering
  • Seabed
  • Unmanned Underwater Vehicles

Fields of Study

  • Engineering

Readers

  • Radio communications and signal processing.
  • Speech Processing/Speech Recognition.