H
Heechun Song
Researcher at Scripps Institution of Oceanography
Publications - 139
Citations - 4412
Heechun Song is an academic researcher from Scripps Institution of Oceanography. The author has contributed to research in topics: Underwater acoustic communication & Beamforming. The author has an hindex of 32, co-authored 138 publications receiving 4042 citations. Previous affiliations of Heechun Song include Scripps Health & University of California, San Diego.
Papers
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Journal ArticleDOI
Phase conjugation in the ocean: Experimental demonstration of an acoustic time-reversal mirror
William A. Kuperman,William S. Hodgkiss,Heechun Song,Tuncay Akal,Carlo M. Ferla,Darrell R. Jackson +5 more
TL;DR: In this paper, a phase conjugate array was implemented to spatially and temporally refocus an incident acoustic field back to its origin in the Mediterranean Sea by transmitting a 50-ms pulse from the SRT to the SRA, digitizing the received signal and retransmitting the time reversed signals from all the sources of the sRA.
Journal ArticleDOI
An initial demonstration of underwater acoustic communication using time reversal
TL;DR: An at-sea experiment to measure the focus of a 3.5-kHz centered time-reversal mirror was conducted in three different environments and time reversal is shown to be an effective approach for mitigating inter-symbol interference caused by channel multipath.
Journal ArticleDOI
A long-range and variable focus phase-conjugation experiment in shallow water
William S. Hodgkiss,Heechun Song,William A. Kuperman,Tuncay Akal,Carlo M. Ferla,Darrell R. Jackson +5 more
TL;DR: Song et al. as discussed by the authors extended the range of focus from 6 km out to 30 km, and verified a new technique to refocus at ranges other than that of the probe source.
Journal ArticleDOI
Underwater acoustic communications using time reversal
TL;DR: In this article, a time-reversal communication system is proposed to improve data telemetry in the ocean by taking advantage of the focal properties of time reversal, which mitigates channel fading, reduces the dispersion caused by the channel, and increases the signal strength.
Journal ArticleDOI
Improvement of Time-Reversal Communications Using Adaptive Channel Equalizers
TL;DR: Using multilevel quadrature amplitude modulation (M-QAM) in shallow water, it is demonstrated that the performance of time-reversal communications can be improved significantly by cascading the received time series with an adaptive channel equalizer to remove the residual ISI.