Passive time reversal acoustic communications through shallow-water internal waves

Aijun Song, Mohsen Badiey, Arthur E. Newhall, James F. Lynch, Harry A. Deferrari, Boris G. Katsnelson

Research output: Contribution to journalArticlepeer-review

33 Scopus citations


During a 12-h period in the 2006 Shallow Water Experiment (SW06), binary phase shift keying (BPSK) signals at the carrier frequencies of 813 and 1627 Hz were propagated over a 19.8-km sourcereceiver range when a packet of strong internal waves passed through the acoustic track. The communication data are analyzed by time reversal processing followed by a single-channel decision feedback equalizer. Two types of internal wave effects are investigated in the context of acoustic communications. One is the rapid channel fluctuation within 90-s data packets. It can be characterized as decreased channel coherence, which was the result of fast sound-speed perturbations during the internal wave passage. We show its effect on the time reversal receiver performance and apply channel tracking in the receiver to counteract such fluctuation. The other one is the long-term (in the scale of hours) performance degradation in the depressed waveguide when the internal waves passed through the acoustic track. Even with channel tracking, the time reversal receiver experiences average 34-dB decrease in the output signal-to-noise ratio (SNR). Such long-term performance degradation is explained by the ray approximation in the depressed waveguide.

Original languageEnglish (US)
Article number5618583
Pages (from-to)756-765
Number of pages10
JournalIEEE Journal of Oceanic Engineering
Issue number4
StatePublished - Oct 2010
Externally publishedYes


  • Acoustic communications
  • decision feedback equalizers
  • internal waves
  • time reversal processing

ASJC Scopus subject areas

  • Ocean Engineering
  • Mechanical Engineering
  • Electrical and Electronic Engineering


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