J. Sens. Actuator Netw. 2013, 2(4), 700-716; doi:10.3390/jsan2040700
Article

MIMO Underwater Acoustic Communications in Ports and Shallow Waters at Very High Frequency

Received: 14 August 2013; in revised form: 23 September 2013 / Accepted: 24 September 2013 / Published: 11 October 2013
(This article belongs to the Special Issue Underwater Sensor Networks)
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract: Hermes is a Single-Input Single-Output (SISO) underwater acoustic modem that achieves very high-bit rate digital communications in ports and shallow waters. Here, the authors study the capability of Hermes to support Multiple-Input-Multiple-Output (MIMO) technology. A least-square channel estimation algorithm is used to evaluate multiple MIMO channel impulse responses at the receiver end. A deconvolution routine is used to separate the messages coming from different sources. This paper covers the performance of both the channel estimation and the MIMO deconvolution processes using either simulated data or field data. The MIMO equalization performance is measured by comparing three relative root mean-squared errors (RMSE), obtained by calculations between the source signal (a pseudo-noise sequence) and the corresponding received MIMO signal at various stages of the deconvolution process; prior to any interference removal, at the output of the Linear Equalization (LE) process and at the output of an interference cancellation process with complete a priori knowledge of the transmitted signal. Using the simulated data, the RMSE using LE is −20.5 dB (where 0 dB corresponds to 100% of relative error) while the lower bound value is −33.4 dB. Using experimental data, the LE performance is −3.3 dB and the lower bound RMSE value is −27 dB.
Keywords: MIMO; underwater; acoustic communications; channel estimation; equalization
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MDPI and ACS Style

Real, G.; Beaujean, P.-P.; Bouvet, P.-J. MIMO Underwater Acoustic Communications in Ports and Shallow Waters at Very High Frequency. J. Sens. Actuator Netw. 2013, 2, 700-716.

AMA Style

Real G, Beaujean P-P, Bouvet P-J. MIMO Underwater Acoustic Communications in Ports and Shallow Waters at Very High Frequency. Journal of Sensor and Actuator Networks. 2013; 2(4):700-716.

Chicago/Turabian Style

Real, Gaultier; Beaujean, Pierre-Philippe; Bouvet, Pierre-Jean. 2013. "MIMO Underwater Acoustic Communications in Ports and Shallow Waters at Very High Frequency." J. Sens. Actuator Netw. 2, no. 4: 700-716.

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