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Title: Blind source separation using a spatial fourth-order cumulant matrix-pencil.
Creator: Dishman, John Fitzgerald., Florida Atlantic University, Aalo, Valentine A., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description: The research presented investigates the use of cumulants in conjunction with a spectral estimation technique of the signal subspace to perform the blind separation of statistically independent signals with low signal-to-noise ratios under a narrowband assumption. A new blind source separation (BSS) algorithm is developed that makes use of the generalized eigen analysis of a matrix pencil defined on two similar spatial fourth-order cumulant matrices. The algorithm works in the presence of...
Show moreThe research presented investigates the use of cumulants in conjunction with a spectral estimation technique of the signal subspace to perform the blind separation of statistically independent signals with low signal-to-noise ratios under a narrowband assumption. A new blind source separation (BSS) algorithm is developed that makes use of the generalized eigen analysis of a matrix pencil defined on two similar spatial fourth-order cumulant matrices. The algorithm works in the presence of spatially and/or temporally correlated noise and, unlike most existing higher-order BSS techniques, is based on a spectral estimation technique rather than a closed loop optimization of a contrast function, for which the convergence is often problematic. The dissertation makes several contributions to the area of blind source separation. These include: (1) Development of a robust blind source separation technique that is based on higher-order cumulant based principle component analysis that works at low signal-to-noise ratios in the presence of temporally and/or spatially correlated noise. (2) A novel definition of a spatial fourth-order cumulant matrix suited to blind source separation with non-equal gain and/or directional sensors. (3) The definition of a spatial fourth-order cumulant matrix-pencil using temporal information. (4) The concept of separation power efficiency (SPE) as a measure of the algorithm's performance. Two alternative definitions for the spatial fourth-order cumulant matrix that are found in the literature are also presented and used by the algorithm for comparison. Additionally, the research contributes the concept of wide sense equivalence between matrix-pencils to the field of matrix algebra. The algorithm's performance is verified by computer simulation using realistic digital communications signals in white noise. Random mixing matrices are generated to ensure the algorithm's performance is independent of array geometry. The computer results are promising and show that the algorithm works well down to input signal-to-noise ratios of -6 dB, and using as few as 250 x 103 samples.
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Date Issued: 2001
PURL: http://purl.flvc.org/fcla/dt/11963
Subject Headings: Matrix pencils, Adaptive signal processing, Matrices
Format: Document (PDF)

Title: High-speed acoustic communication in shallow water using spatio-temporal adaptive array processing.
Creator: Beaujean, Pierre-Philippe, Florida Atlantic University, LeBlanc, Lester R., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: A novel method of achieving stable high-speed underwater acoustic communication with a fairly low-complexity of implementation is proposed. The proposed approach is to split the space and time processing into two separate sub-optimal processes. As a result, processing complexity is significantly reduced and the instabilities associated with large tap vectors at large time-frequency spread products are reduced. The proposed space-time signal processing method utilizes a different beamformer...
Show moreA novel method of achieving stable high-speed underwater acoustic communication with a fairly low-complexity of implementation is proposed. The proposed approach is to split the space and time processing into two separate sub-optimal processes. As a result, processing complexity is significantly reduced and the instabilities associated with large tap vectors at large time-frequency spread products are reduced. The proposed space-time signal processing method utilizes a different beamformer optimization strategy compared to the time domain optimization strategy. This allows to separately adjust the adaptation parameters for the spatial and temporal characteristics of the signal, which have vastly different requirements. The time domain signal is subject to variations in phase that require rapid filter updates whereas the directional characteristics of the signal do not vary appreciably over the message length and do not require a rapid adaptation response. The proposed method allows for high-speed underwater acoustic communication in very shallow water using coherent modulation techniques, and offers a series of unique features: significant reduction of the signal-to-noise and interference ratio (SNIR), improvement of the bandwidth efficiency by reduction of the forward-error coding redundancy requirements, real-time evaluation of the time-spread by Doppler spread product (BL) and channel stability estimate. Experimental results demonstrate that stable acoustic communication can be achieved at rates of 32000 bits per second at a distance of 3 km, in 40 feet of water and in sea-state 2 conditions. Fast and slow fading properties of the channel are measured, as the BL product can vary by a decade in 116 ms, and by two decades within minutes, from 0.001 to 0.1. The real-time analysis shows a strong correlation between time spread, Doppler spread, spatial coherence of the acoustic channel and communication performance. Overall, this research provides more scientific and experimental ground to understand the limitations of multi-channel adaptive receiver techniques in terms of stability, hardware requirements and channel tracking capability.
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Date Issued: 2001
PURL: http://purl.flvc.org/fcla/dt/11952
Subject Headings: Underwater acoustic telemetry, Adaptive signal processing
Format: Document (PDF)

Title: The directionality of noise created by turbulent flow over roughness.
Creator: Kaufman, Gerard P., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Flow over a rough surface is known to radiate sound as a dipole source that is directional. In order to better understand this source, measurements are being made in a wind tunnel using a microphone array. The measurements collected by a microphone array are beamformed to give a source image and can be deconvolved with an assumed point spread function in order to obtain the source levels. This thesis considers alternative analysis algorithms that can be used to analyze wind tunnel data. Only...
Show moreFlow over a rough surface is known to radiate sound as a dipole source that is directional. In order to better understand this source, measurements are being made in a wind tunnel using a microphone array. The measurements collected by a microphone array are beamformed to give a source image and can be deconvolved with an assumed point spread function in order to obtain the source levels. This thesis considers alternative analysis algorithms that can be used to analyze wind tunnel data. Only numerical examples of how these algorithms work will be presented and the analysis of real data will be considered in later studies. It will be shown how estimates can be made of the source directivity by comparing the measured data with a theoretical source model and minimizing the error between the model and the measurements.
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Date Issued: 2011
PURL: http://purl.flvc.org/FAU/3171394
Subject Headings: Electromagnetic fields, Signal processing, Digital techniques, Noise control, Adaptive signal processing, Acoustic emission, Measurement
Format: Document (PDF)

Title: Maximum likelihood estimates of azimuth and elevation for a frequency-hopped active source using a tetrahedral ultra-short baseline.
Creator: Warin, Raphael., Florida Atlantic University, Beaujean, Pierre-Philippe, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Ultra-Short-BaseLine (USBL) is the most practical underwater acoustic positioning system for autonomous underwater vehicles because of its small space requirement. The objective of this research is to develop a USBL system capable of estimating a source location transmitting frequency-hopped tones sequences. Such sequences are characteristic of spread spectrum signaling used in underwater acoustic communication network. It must be able to provide azimuth and elevation of a modem-type source...
Show moreUltra-Short-BaseLine (USBL) is the most practical underwater acoustic positioning system for autonomous underwater vehicles because of its small space requirement. The objective of this research is to develop a USBL system capable of estimating a source location transmitting frequency-hopped tones sequences. Such sequences are characteristic of spread spectrum signaling used in underwater acoustic communication network. It must be able to provide azimuth and elevation of a modem-type source with an accuracy of 0.3 degrees; for both angles using the synchronization stage of the transmission. The acoustic antenna is composed of four transducers arranged as a tetrahedron. Using the model of Quazi and Lerro, which provides an expression for the variance of the bearing angle, azimuth and elevation of the transmitter are estimated employing maximum likelihood estimation. This system is simulated, tested and calibrated in a tank. Simulated results satisfy the requirement with a SNR of 32dB and 8 symbols. The latest experimental measurements present an accuracy of 3 degrees.
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Date Issued: 2004
PURL: http://purl.flvc.org/fcla/dt/13135
Subject Headings: Underwater acoustics--Instruments, Underwater acoustic telemetry, Signal processing--Technique, Adaptive signal processing
Format: Document (PDF)

Title: Estimation of the scattering function of fading channels for acoustic communications in shallow waters.
Creator: Allemand, Vincent., Florida Atlantic University, Beaujean, Pierre-Philippe
Abstract/Description: The measurement of the Scattering function of time-variant fading channels is of strong interest in the field of underwater acoustic communications, as it indicates the limitations of the channel capacity. It also helps reducing the development time of acoustic communication systems and the need for on-site tests using so-called "fading simulators". The Scattering function is interpreted as the expected power received at a given time-delay and frequency shift for a given signal transmitted...
Show moreThe measurement of the Scattering function of time-variant fading channels is of strong interest in the field of underwater acoustic communications, as it indicates the limitations of the channel capacity. It also helps reducing the development time of acoustic communication systems and the need for on-site tests using so-called "fading simulators". The Scattering function is interpreted as the expected power received at a given time-delay and frequency shift for a given signal transmitted through the acoustic channel. It has been estimated using a fourth-moment method developed by Kailath from 18 to 30 kHz, 8-ms broad-band chirps and 20--28 kHz, 28-ms pseudo noise sequences. These signals were transmitted periodically in the shallow coastal waters of South Florida from a static source, and recorded from a 64-channel receiver array located at a distance of 1000 meters. Spatial beamforming has been applied to study the spatial sensitivity of the scattering function.
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Date Issued: 2005
PURL: http://purl.flvc.org/fcla/dt/13230
Subject Headings: Underwater acoustic telemetry, Signal processing--Digital techniques, Underwater acoustics--Mathematical models, Adaptive signal processing
Format: Document (PDF)

Title: Mobile docking of REMUS-100 equipped with USBL-APS to an unmanned surface vehicle: a performance feasibility study.
Creator: Miranda, Mario II, Beaujean, Pierre-Philippe, Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The overall objective of this work is to evaluate the ability of homing and docking an unmanned underwater vehicle (Hydroid REMUS 100 UUV) to a moving unmanned surface vehicle (Wave-Adaptive Modular Surface Vehicle USV) using a Hydroid Digital Ultra-Short Baseline (DUSBL) acoustic positioning system (APS), as a primary navigation source. An understanding of how the UUV can rendezvous with a stationary USV first is presented, then followed by a moving USV. Inherently, the DUSBL-APS is...
Show moreThe overall objective of this work is to evaluate the ability of homing and docking an unmanned underwater vehicle (Hydroid REMUS 100 UUV) to a moving unmanned surface vehicle (Wave-Adaptive Modular Surface Vehicle USV) using a Hydroid Digital Ultra-Short Baseline (DUSBL) acoustic positioning system (APS), as a primary navigation source. An understanding of how the UUV can rendezvous with a stationary USV first is presented, then followed by a moving USV. Inherently, the DUSBL-APS is susceptible to error due to the physical phenomena of the underwater acoustic channel (e.g. ambient noise, attenuation and ray refraction). The development of an APS model has allowed the authors to forecast the UUV’s position and the estimated track line of the USV as determined by the DUSBL acoustic sensor. In this model, focus is placed on three main elements: 1) the acoustic channel and sound ray refraction when propagating in an in-homogeneous medium; 2) the detection component of an ideal DUSBL-APS using the Neyman-Pearson criterion; 3) the signal-to-noise ratio (SNR) and receiver directivity impact on position estimation. The simulation tool is compared against actual open water homing results in terms of the estimated source position between the simulated and the actual USBL range and bearing information.
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Date Issued: 2014
PURL: http://purl.flvc.org/fau/fd/FA00004140, http://purl.flvc.org/fau/fd/FA00004140
Subject Headings: Adaptive signal processing, Mobile robots, Underwater acoustic telemetry
Format: Document (PDF)

Title: Motion Compensation of an Ultra Short Baseline Array for the Acoustic Positioning of an Underwater Vehicle for Port Operations.
Creator: Bon, Antoine, Beaujean, Pierre-Philippe, Florida Atlantic University
Abstract/Description: A Motion Compensated (MC) Ultra Short Baseline (USBL) Acoustic Positioning System (APS) operable in shallow water and port environment has been implemented at Florida Atlantic University. Multi-tones signal modulation and log-likelihood maximization enable this APS to operate in volumes of water of less than 10 cubic meters. Standard deviations of the acoustic source elevation and azimuth estimates were computed to be 3 degrees in an 8 cubic meters test tank, and reduce to 0.9 degree in a 2...
Show moreA Motion Compensated (MC) Ultra Short Baseline (USBL) Acoustic Positioning System (APS) operable in shallow water and port environment has been implemented at Florida Atlantic University. Multi-tones signal modulation and log-likelihood maximization enable this APS to operate in volumes of water of less than 10 cubic meters. Standard deviations of the acoustic source elevation and azimuth estimates were computed to be 3 degrees in an 8 cubic meters test tank, and reduce to 0.9 degree in a 2 meters deep marina. The motion compensating system estimates the array position and orientation while merging noisy measurements from a Magnetic, Angular Rate, and Gravity (MARG) sensor and a Differential Global Positioning System (DGPS) using Kalman filters. Experiments show 0.67 and 2.67 degrees of error for the array tilt and heading estimates, and 0.74 meter for the array position estimate.
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Date Issued: 2007
PURL: http://purl.flvc.org/fau/fd/FA00012507
Subject Headings: Underwater navigation, Acoustical engineering, Adaptive signal processing, Underwater acoustic telemetry
Format: Document (PDF)

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)

Title: Wind Feedforward Control of a USV.
Creator: Qu, Huajin, von Ellenrieder, Karl, Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: In this research, a wind feedforward (FF) controller has been developed to augment closed loop feedback controllers for the position and heading station keeping control of Unmanned Surface Vehicles (USVs). The performance of the controllers was experimentally tested using a 16 foot USV in an outdoor marine environment. The FF controller was combined with three nonlinear feedback controllers, a Proportional–Derivative (PD) controller, a Backstepping (BS) controller, and a Sliding mode (SM)...
Show moreIn this research, a wind feedforward (FF) controller has been developed to augment closed loop feedback controllers for the position and heading station keeping control of Unmanned Surface Vehicles (USVs). The performance of the controllers was experimentally tested using a 16 foot USV in an outdoor marine environment. The FF controller was combined with three nonlinear feedback controllers, a Proportional–Derivative (PD) controller, a Backstepping (BS) controller, and a Sliding mode (SM) controller, to improve the station-keeping performance of the USV. To address the problem of wind model uncertainties, adaptive wind feedforward (AFF) control schemes are also applied to the FF controller, and implemented together with the BS and SM feedback controllers. The adaptive law is derived using Lyapunov Theory to ensure stability. On-water station keeping tests of each combination of FF and feedback controllers were conducted in the U.S. Intracoastal Waterway in Dania Beach, FL USA. Five runs of each test condition were performed; each run lasted at least 10 minutes. The experiments were conducted in Sea State 1 with an average wind speed of between 1 to 4 meters per second and significant wave heights of less than 0.2 meters. When the performance of the controllers is compared using the Integral of the Absolute Error (IAE) of position criterion, the experimental results indicate that the BS and SM feedback controllers significantly outperform the PD feedback controller (e.g. a 33% and a 44% decreases in the IAE, respectively). It is also found that FF is beneficial for all three feedback controllers and that AFF can further improve the station keeping performance. For example, a BS feedback control combined with AFF control reduces the IAE by 25% when compared with a BS feedback controller combined with a non-adaptive FF controller. Among the eight combinations of controllers tested, SM feedback control combined with AFF control gives the best station keeping performance with an average position and heading error of 0.32 meters and 4.76 degrees, respectively.
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Date Issued: 2016
PURL: http://purl.flvc.org/fau/fd/FA00004623, http://purl.flvc.org/fau/fd/FA00004623
Subject Headings: Wind turbines--Control., Adaptive control systems., Adaptive signal processing., Intelligent control systems., Wind-pressure., Intelligent sensors.
Format: Document (PDF)

Title: Characterizing the Magnetic Signature of Internal Waves.
Creator: Nieves, Eric, Beaujean, Pierre-Philippe, Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: This study is performed in tandem with numerous experiments performed by the U.S. Navy to characterize the ocean environment in the South Florida region. The research performed in this study includes signal processing steps for isolating ocean phenomena, such as internal waves, in the magnetic field. Raw magnetometer signals, one on shore and one underwater, are processed and removed of common distortions. They are then run through a series of filtering techniques, including frequency domain...
Show moreThis study is performed in tandem with numerous experiments performed by the U.S. Navy to characterize the ocean environment in the South Florida region. The research performed in this study includes signal processing steps for isolating ocean phenomena, such as internal waves, in the magnetic field. Raw magnetometer signals, one on shore and one underwater, are processed and removed of common distortions. They are then run through a series of filtering techniques, including frequency domain cancellation (FDC). The results of the filtered magnetic residual are compared to similarly processed Acoustic Doppler Current Profiler (ADCP) data to correlate whether a magnetic signature is caused by ocean phenomena.
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Date Issued: 2017
PURL: http://purl.flvc.org/fau/fd/FA00004917, http://purl.flvc.org/fau/fd/FA00004917
Subject Headings: Ocean currents--Measurement., Adaptive signal processing., Wave-motion, Theory of., Wavelets (Mathematics)
Format: Document (PDF)

Title: Acoustic tracking of an unmanned underwater vehicle using a passive ultrashort baseline array and a single long baseline beacon.
Creator: Seaton, Kyle L., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: This thesis discusses a new approach to tracking the REMUS 100 AUV using a modified version of the Florida Atlantic University (FAU) ultrashort baseline (USBL) acoustic positioning system (APS). The REMUS 100 is designed to utilize a long baseline (LBL) acoustic positioning system to obtain positioning data in mid-mission. If the placement of one of the transponders of the LBL field is known, then tracking the position of the REMUS 100 AUV using a passive USBL array is possible. As part of...
Show moreThis thesis discusses a new approach to tracking the REMUS 100 AUV using a modified version of the Florida Atlantic University (FAU) ultrashort baseline (USBL) acoustic positioning system (APS). The REMUS 100 is designed to utilize a long baseline (LBL) acoustic positioning system to obtain positioning data in mid-mission. If the placement of one of the transponders of the LBL field is known, then tracking the position of the REMUS 100 AUV using a passive USBL array is possible. As part of the research for this thesis, the FAU USBL system was used to find a relative range between the REMUS 100 ranger and a LBL transponder. This relative range was then combined with direction of arrival information and LBL field component position information to determine an absolute position of the REMUS 100 ranger. The outcome was the demonstration of a passive USBL based tracking system.
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Date Issued: 2013
PURL: http://purl.flvc.org/fcla/dt/3361057
Subject Headings: Underwater acoustic telemetry, Acoustic velocity meters, Array processors, Acoustical engineering, Adaptive signal processing
Format: Document (PDF)

Title: Nonlinear control of an unmanned amphibious vehicle.
Creator: Alvarez, Jose L., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The DUCKW-Ling is an 8.3 foot long, amphibious water plane area twin hull (SWATH) concept vehicle which is propelled by a pair of crawler tracks on land and dual propellers when water-borne. In its operational zone, the vehicle's dynamics change dramatically as it transitions from being completely water-borne and buoyancy supported to being completely land-borne and track supported. In the water environment, a cascaded, first-order sliding mode controller was used to control the surge and...
Show moreThe DUCKW-Ling is an 8.3 foot long, amphibious water plane area twin hull (SWATH) concept vehicle which is propelled by a pair of crawler tracks on land and dual propellers when water-borne. In its operational zone, the vehicle's dynamics change dramatically as it transitions from being completely water-borne and buoyancy supported to being completely land-borne and track supported. In the water environment, a cascaded, first-order sliding mode controller was used to control the surge and heading of the vehicle, and was capable of having a faster response when compared to using a proportional controller. Additionally, field trials of the DUKW-Ling show the capability of the vehicle to navigate and track predetermined waypoints in both terrestrial and aquatic terrains. In the transitional zone, the electric motor current from the tracks was used as the feedback mechanism to adequately actuate the propellers and tracks in the system as the dynamics of the vehicle change.
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Date Issued: 2013
PURL: http://purl.flvc.org/fcla/dt/3362334
Subject Headings: Nonlinear control theory, Feedback control systems, Motor vehicles, Amphibious, Design and construction, Adaptive signal processing
Format: Document (PDF)

Title: A modular guidance, navigation and control system for unmanned surface vehicles.
Creator: Furfaro, Thomas C., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The design and integration of an unmanned surface vehicle (USV) control system is described. A survey of related work in both USV control, and unmanned vehicle operating software is presented. The hardware subsystem comprising a modular Guidance, Navigation, and Control (GNC) package is explained. A multi-threaded software architecture is presented, utilizing a decentralized, mutex-protected shared memory inter-process communication subsystem to provide interoperability with additional...
Show moreThe design and integration of an unmanned surface vehicle (USV) control system is described. A survey of related work in both USV control, and unmanned vehicle operating software is presented. The hardware subsystem comprising a modular Guidance, Navigation, and Control (GNC) package is explained. A multi-threaded software architecture is presented, utilizing a decentralized, mutex-protected shared memory inter-process communication subsystem to provide interoperability with additional software modules. A generic GNC approach is presented, with particular elaboration on a virtual rudder abstraction of differential thrust platforms. A MATLAB Simulink simulation is presented as a tool for developing an appropriate controller structure, the result of which was implemented on the target platform. Software validation is presented via a series of sea trials. The USV was tested both in open- and closed-loop control configurations, the results of which are presented here. Lastly recommendations for future development of the GNC system are enumerated.
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Date Issued: 2012
PURL: http://purl.flvc.org/FAU/3342052
Subject Headings: Underwater navigation, Adaptive signal processing, Inertial navigation systems, Oceanographic instruments, Development
Format: Document (PDF)

Title: A low-cost, high rate motion measurement system for an unmanned surface vehicle with underwater navigation and oceanographic applications.
Creator: Gelin, Chrystel., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Standard GPS receivers are unable to provide the rate or precision required when used on a small vessel such as an Unmanned Surface Vehicles (USVs). To overcome this, the thesis presents a low cost high rate motion measurement system for an USV with underwater and oceanographic purposes. The work integrates an Inertial Measurement Unit (IMU), a GPS receiver, a flux-gate compass, a tilt sensor and develops a software package, using real time data fusion methods, for an USV to aid in the...
Show moreStandard GPS receivers are unable to provide the rate or precision required when used on a small vessel such as an Unmanned Surface Vehicles (USVs). To overcome this, the thesis presents a low cost high rate motion measurement system for an USV with underwater and oceanographic purposes. The work integrates an Inertial Measurement Unit (IMU), a GPS receiver, a flux-gate compass, a tilt sensor and develops a software package, using real time data fusion methods, for an USV to aid in the navigation and control as well as controlling an onboard Acoustic Doppler Current Profiler (ADCP).While ADCPs non-intrusively measure water flow, they suffer from the inability to discriminate between motions in the water column and self-motion. Thus, the vessel motion contamination needs to be removed to analyze the data and the system developed in this thesis provides the motion measurements and processing to accomplish this task.
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Date Issued: 2010
PURL: http://purl.flvc.org/FAU/2709690
Subject Headings: Oceanographic instruments, Evaluation, Underwater navigation, Adaptive signal processing, Inertial navigation systems, Wave motion, Theory of
Format: Document (PDF)

Title: Optimal chunk-based resource allocation for OFDMA systems with multiple BER requirements.
Creator: He, Tianzhou, Wang, Xin, Florida Atlantic University, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description: In wireless orthogonal frequency division multiple-access (OFDMA) standards, subcarriers are grouped into chunks and a chunk of subcarriers is made as the minimum allocation unit for subcarrier allocation. We investigate the chunk-based resource allocation for OFDMA downlink, where data streams contain packets with diverse bit-errorrate (BER) requirements. Supposing that adaptive transmissions are based on a number of discrete modulation and coding modes, we derive the optimal resource...
Show moreIn wireless orthogonal frequency division multiple-access (OFDMA) standards, subcarriers are grouped into chunks and a chunk of subcarriers is made as the minimum allocation unit for subcarrier allocation. We investigate the chunk-based resource allocation for OFDMA downlink, where data streams contain packets with diverse bit-errorrate (BER) requirements. Supposing that adaptive transmissions are based on a number of discrete modulation and coding modes, we derive the optimal resource allocation scheme that maximizes the weighted sum of average user rates under the multiple BER and total power constraints. With proper formulation, the relevant optimization problem is cast as an integer linear program (ILP). We can rigorously prove that the zero duality gap holds for the formulated ILP and its dual problem. Furthermore, it is shown that the optimal strategy for this problem can be obtained through Lagrange dual-based gradient iterations with fast convergence and low computational complexity per iteration. Relying on the stochastic optimization tools, we further develop a novel on-line algorithm capable of dynamically learning the underlying channel distribution and asymptotically approaching the optimal strategy without knowledge of intended wireless channels a priori. In addition, we extend the proposed approach to maximizing the a-fair utility functions of average user rates, and show that such a utility maximization can nicely balance the trade-off between the total throughput and fairness among users.
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Date Issued: 2014
PURL: http://purl.flvc.org/fau/fd/FA00004291, http://purl.flvc.org/fau/fd/FA00004291
Subject Headings: Adaptive signal processing, Mathematical optimization, Orthogonal frequency division multiplexing, Wireless communication systems
Format: Document (PDF)

Title: System identification methodology for a wave adaptive modular unmanned surface vehicle.
Creator: Mask, Janine L., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The design, implementation, and testing of an experimental setup intended to evaluate the dynamic maneuvering performance of the Wave Adaptive Modular Vessel (WAM-V) class USV12, a 3.7 meter unmanned surface vehicle (USV) is described. A comprehensive sensor package was designed, fabricated and assembled to record the vehicle's dynamic response to various control inputs. All subsystems were fabricated and installed on a test vehicle, GUSS, and full system, open-loop maneuvering tests were...
Show moreThe design, implementation, and testing of an experimental setup intended to evaluate the dynamic maneuvering performance of the Wave Adaptive Modular Vessel (WAM-V) class USV12, a 3.7 meter unmanned surface vehicle (USV) is described. A comprehensive sensor package was designed, fabricated and assembled to record the vehicle's dynamic response to various control inputs. All subsystems were fabricated and installed on a test vehicle, GUSS, and full system, open-loop maneuvering tests were conducted to show validity of data collection technique. Simulations were performed using model parameters found in the literature to create a "simulated experimental" data set, upon which system identification techniques were used to rediscover a suitable model with similar parameterization. Combined, the sensor package and the method for creating this model support future work in the design of automatic control, navigation, and guidance systems for the WAM-V USV12.
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Date Issued: 2011
PURL: http://purl.flvc.org/FAU/3332720
Subject Headings: Oceanographic instruments, Evaluation, Wave motion, Theory of, Inertial navigation systems, Adaptive signal processing
Format: Document (PDF)

Title: Spectral refinement to speech enhancement.
Creator: Charoenruengkit, Werayuth., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description: The goal of a speech enhancement algorithm is to remove noise and recover the original signal with as little distortion and residual noise as possible. Most successful real-time algorithms thereof have done in the frequency domain where the frequency amplitude of clean speech is estimated per short-time frame of the noisy signal. The state of-the-art short-time spectral amplitude estimator algorithms estimate the clean spectral amplitude in terms of the power spectral density (PSD) function...
Show moreThe goal of a speech enhancement algorithm is to remove noise and recover the original signal with as little distortion and residual noise as possible. Most successful real-time algorithms thereof have done in the frequency domain where the frequency amplitude of clean speech is estimated per short-time frame of the noisy signal. The state of-the-art short-time spectral amplitude estimator algorithms estimate the clean spectral amplitude in terms of the power spectral density (PSD) function of the noisy signal. The PSD has to be computed from a large ensemble of signal realizations. However, in practice, it may only be estimated from a finite-length sample of a single realization of the signal. Estimation errors introduced by these limitations deviate the solution from the optimal. Various spectral estimation techniques, many with added spectral smoothing, have been investigated for decades to reduce the estimation errors. These algorithms do not address significantly issue on quality of speech as perceived by a human. This dissertation presents analysis and techniques that offer spectral refinements toward speech enhancement. We present an analytical framework of the effect of spectral estimate variance on the performance of speech enhancement. We use the variance quality factor (VQF) as a quantitative measure of estimated spectra. We show that reducing the spectral estimator VQF reduces significantly the VQF of the enhanced speech. The Autoregressive Multitaper (ARMT) spectral estimate is proposed as a low VQF spectral estimator for use in speech enhancement algorithms. An innovative method of incorporating a speech production model using multiband excitation is also presented as a technique to emphasize the harmonic components of the glottal speech input., The preconditioning of the noisy estimates by exploiting other avenues of information, such as pitch estimation and the speech production model, effectively increases the localized narrow-band signal-to noise ratio (SNR) of the noisy signal, which is subsequently denoised by the amplitude gain. Combined with voicing structure enhancement, the ARMT spectral estimate delivers enhanced speech with sound clarity desirable to human listeners. The resulting improvements in enhanced speech are observed to be significant with both Objective and Subjective measurement.
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Date Issued: 2009
PURL: http://purl.flvc.org/FAU/186327
Subject Headings: Adaptive signal processing, Digital techniques, Spectral theory (Mathematics), Noise control, Fuzzy algorithms, Speech processing systems, Digital techniques
Format: Document (PDF)

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)

Title: Automated Launch and Recovery of an Autonomous Underwater Vehicle from an Unmanned Surface Vessel.
Creator: Sarda, Edoardo I, Dhanak, Manhar R., Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Research on collaboration among unmanned platforms is essential to improve the applications for autonomous missions, by expanding the working environment of the robotic systems, and reducing the risks and the costs associated with conducting manned operations. This research is devoted to enable the collaboration between an Unmanned Surface Vehicle (USV) and an Autonomous Underwater Vehicle (AUV), by allowing the first one to launch and recover the second one. The objective of this...
Show moreResearch on collaboration among unmanned platforms is essential to improve the applications for autonomous missions, by expanding the working environment of the robotic systems, and reducing the risks and the costs associated with conducting manned operations. This research is devoted to enable the collaboration between an Unmanned Surface Vehicle (USV) and an Autonomous Underwater Vehicle (AUV), by allowing the first one to launch and recover the second one. The objective of this dissertation is to identify possible methods to launch and recover a REMUS 100 AUV from a WAM-V 16 USV, thus developing this capability by designing and implementing a launch and recovery system (LARS). To meet this objective, a series of preliminary experiments was first performed to identify two distinct methods to launch and recover the AUV: mobile and semi-stationary. Both methods have been simulated using the Orcaflex software. Subsequently, the necessary control systems to create the mandatory USV autonomy for the purpose of launch and recovery were developed. Specifically, a series of low-level controllers were designed and implemented to enable two autonomous maneuvers on the USV: station-keeping and speed & heading control. In addition, a level of intelligence to autonomously identify the optimal operating conditions within the vehicles' working environment, was derived and integrated on the USV. Lastly, a LARS was designed and implemented on the vehicles to perform the operation following the proposed methodology. The LARS and all subsystems developed for this research were extensively tested through sea-trials. The methodology for launch and recovery, the design of the LARS and the experimental findings are reported in this document.
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Date Issued: 2016
PURL: http://purl.flvc.org/fau/fd/FA00004631, http://purl.flvc.org/fau/fd/FA00004631
Subject Headings: Underwater acoustic telemetry., Fuzzy systems., Nonlinear control theory., Adaptive signal processing., Oceanographic submersibles--Automatic control., Submersibles--Control systems.
Format: Document (PDF)

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)

Adaptive signal processing (20)	+ -
Underwater acoustic telemetry (9)	+ -
Wireless communication systems (4)	+ -
Adaptive signal processing. (3)	+ -
Inertial navigation systems (3)	+ -

MIMO systems (3)	+ -
Oceanographic instruments (3)	+ -
Underwater navigation (3)	+ -
Acoustical engineering (2)	+ -
Digital techniques (2)	+ -
Evaluation (2)	+ -
Noise control (2)	+ -
Nonlinear control theory (2)	+ -
Underwater acoustics -- Evaluation (2)	+ -
Wave motion, Theory of (2)	+ -
Acoustic emission (1)	+ -
Acoustic velocity meters (1)	+ -
Adaptive control systems. (1)	+ -
Adaptive control systems (1)	+ -
Array processors (1)	+ -
Computer vision (1)	+ -
Design and construction (1)	+ -
Development (1)	+ -
Electromagnetic fields (1)	+ -
Expert systems (Computer science) (1)	+ -
Feedback control systems (1)	+ -
Fuzzy algorithms (1)	+ -
Fuzzy sets (1)	+ -
Fuzzy systems (1)	+ -
Fuzzy systems. (1)	+ -

College of Engineering and Computer Science (20)	+ -
Department of Ocean and Mechanical Engineering (16)	+ -
Florida Atlantic University (16)	+ -
Beaujean, Pierre-Philippe (8)	+ -
Department of Computer and Electrical Engineering and Computer Science (4)	+ -

Dhanak, Manhar R. (2)	+ -
AL-Ghanem, Waleed Khalid (1)	+ -
Aalo, Valentine A. (1)	+ -
Allemand, Vincent. (1)	+ -
Alvarez, Jose L. (1)	+ -
An, Pak-Cheung (1)	+ -
Bon, Antoine (1)	+ -
Cardei, Mihaela (1)	+ -
Charoenruengkit, Werayuth. (1)	+ -
Dishman, John Fitzgerald. (1)	+ -
Furfaro, Thomas C. (1)	+ -
Gelin, Chrystel. (1)	+ -
He, Tianzhou (1)	+ -
Kaddouri, Samar (1)	+ -
Kaufman, Gerard P. (1)	+ -
LeBlanc, Lester R. (1)	+ -
Mahgoub, Imad (1)	+ -
Mask, Janine L. (1)	+ -
Mihnea, Amalya (1)	+ -
Miranda, Mario II (1)	+ -
Nieves, Eric (1)	+ -
Pearson, David (1)	+ -
Qu, Huajin (1)	+ -
Sarda, Edoardo I (1)	+ -
Seaton, Kyle L. (1)	+ -

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