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Very high frequency MIMO underwater acoustic communications in ports and shallow waters
Title
Very high frequency MIMO underwater acoustic communications in ports and shallow waters.
Creator
Real, Gaultier., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
This thesis presents the development of a Multiple-Input Multiple-Output (MIMO) capable high bit rate acoustic modem operating at high frequencies. A MIMO channel estimation technique based on Least-Squares (LS) estimation is developed here. Channel deconvolution is completed using a Minimum Mean-Square Error (MMSE) Linear Equalizer (LE). An Interference Cancellation Linear Equalizer (ICLE) is used to provide the theoretical limit of the MIMO deconvolution process. The RMSE of the channel...
Show moreThis thesis presents the development of a Multiple-Input Multiple-Output (MIMO) capable high bit rate acoustic modem operating at high frequencies. A MIMO channel estimation technique based on Least-Squares (LS) estimation is developed here. Channel deconvolution is completed using a Minimum Mean-Square Error (MMSE) Linear Equalizer (LE). An Interference Cancellation Linear Equalizer (ICLE) is used to provide the theoretical limit of the MIMO deconvolution process. The RMSE of the channel estimation process was 1.83 % and 6.1810 %, respectively for simulated and experimental data. Using experimental data, the RMSE before MIMO deconvolution process was 141.3 % and dropped down to 60.224 % and to 4.4545 %, respectively after LE and ICLE. At raw reception, the RMSE was 101.83 % and dropped down to 9.36 % and to 1.86 % using respectively LE and ICLE with simulated data.
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Date Issued
2011
PURL
http://purl.flvc.org/FAU/3333309
Subject Headings
MIMO systems, Wireless communication systems, Underwater acoustics, Fluid dynamics
Format
Document (PDF)
Channel assignment in multi-radio networks
Title
Channel assignment in multi-radio networks.
Creator
Mihnea, Amalya, Cardei, Mihaela, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description
Channel assignment in multi-radio networks is a topic of great importance because the use of multiple channels and multiple radios reduces interference and increases the network throughput. The goal of our research is to design algorithms that maximize the use of available resources while providing robustness to primary users that could reclaim one or more channels. Our algorithms could be used in ad hoc networks, mesh networks, and sensor networks where nodes are equipped with multiple...
Show moreChannel assignment in multi-radio networks is a topic of great importance because the use of multiple channels and multiple radios reduces interference and increases the network throughput. The goal of our research is to design algorithms that maximize the use of available resources while providing robustness to primary users that could reclaim one or more channels. Our algorithms could be used in ad hoc networks, mesh networks, and sensor networks where nodes are equipped with multiple radios. We design algorithms for channel assignment which provide robustness to primary users without assuming an accurate primary user behavior model. We also compute bounds for capacity in grid networks and discuss how the capacity of a network changes when multiple channels are available. Since preserving energy is very important in wireless networks, we focus on algorithms that do not require powerful resources and which use a reduced number of messages.
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Date Issued
2015
PURL
http://purl.flvc.org/fau/fd/FA00004393, http://purl.flvc.org/fau/fd/FA00004393
Subject Headings
Adaptive signal processing, Long Term Evolution (Telecommunications), MIMO systems, Mobile communication systems, Wireless communication systems, Wireless sensor networks
Format
Document (PDF)
Underwater acoustic channel estimation using multiple sources and receivers in shallow waters at very-high frequencies
Title
Underwater acoustic channel estimation using multiple sources and receivers in shallow waters at very-high frequencies.
Creator
Kaddouri, Samar, Beaujean, Pierre-Philippe, Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
The underwater channel poses numerous challenges for acoustic communication. Acoustic waves suffer long propagation delay, multipath, fading, and potentially high spatial and temporal variability. In addition, there is no typical underwater acoustic channel; every body of water exhibits quantifiably different properties. Underwater acoustic modems are traditionally operated at low frequencies. However, the use of broadband, high frequency communication is a good alternative because of the...
Show moreThe underwater channel poses numerous challenges for acoustic communication. Acoustic waves suffer long propagation delay, multipath, fading, and potentially high spatial and temporal variability. In addition, there is no typical underwater acoustic channel; every body of water exhibits quantifiably different properties. Underwater acoustic modems are traditionally operated at low frequencies. However, the use of broadband, high frequency communication is a good alternative because of the lower background noise compared to low-frequencies, considerably larger bandwidth and better source transducer efficiency. One of the biggest problems in the underwater acoustic communications at high frequencies is time-selective fading, resulting in the Doppler spread. While many Doppler detection, estimation and compensation techniques can be found in literature, the applications are limited to systems operating at low frequencies contained within frequencies ranging from a few hundred Hertz to around 30 kHz.
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Date Issued
2015
PURL
http://purl.flvc.org/fau/fd/FA00004384, http://purl.flvc.org/fau/fd/FA00004384
Subject Headings
Adaptive signal processing, MIMO systems, Signal processing -- Ditigal techniques -- Mathematics, Underwater acoustic telemetry, Underwater acoustics -- Evaluation, Wireless communication systems
Format
Document (PDF)
Combined spatial diversity and time equalization for broadband multiple channel underwater acoustic communications
Title
Combined spatial diversity and time equalization for broadband multiple channel underwater acoustic communications.
Creator
Skoro Kaskarovska, Violeta, Beaujean, Pierre-Philippe, Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
High data rate acoustic communications become feasible with the use of communication systems that operate at high frequency. The high frequency acoustic transmission in shallow water endures severe distortion as a result of the extensive intersymbol interference and Doppler shift, caused by the time variable multipath nature of the channel. In this research a Single Input Multiple Output (SIMO) acoustic communication system is developed to improve the reliability of the high data rate...
Show moreHigh data rate acoustic communications become feasible with the use of communication systems that operate at high frequency. The high frequency acoustic transmission in shallow water endures severe distortion as a result of the extensive intersymbol interference and Doppler shift, caused by the time variable multipath nature of the channel. In this research a Single Input Multiple Output (SIMO) acoustic communication system is developed to improve the reliability of the high data rate communications at short range in the shallow water acoustic channel. The proposed SIMO communication system operates at very high frequency and combines spatial diversity and decision feedback equalizer in a multilevel adaptive configuration. The first configuration performs selective combining on the equalized signals from multiple receivers and generates quality feedback parameter for the next level of combining.
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Date Issued
2015
PURL
http://purl.flvc.org/fau/fd/FA00004411, http://purl.flvc.org/fau/fd/FA00004411
Subject Headings
Adaptive signal processing, MIMO systems, Mobile geographic information systems, Signal processing -- Digital techniques, Underwater acoustic telemetry, Underwater acoustics -- Evaluation, Wireless communication systems
Format
Document (PDF)