+publisher:"King Abdullah University of Science and Technology" +contributor:("Turkiyyah, George")

King Abdullah University of Science and Technology

1. Espinoza, Francisco. A New Interpolation Approach for Linearly Constrained Convex Optimization.

Degree: Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division, 2012, King Abdullah University of Science and Technology

URL: http://hdl.handle.net/10754/244891

► In this thesis we propose a new class of Linearly Constrained Convex Optimization methods based on the use of a generalization of Shepard's interpolation formula.… (more)

Subjects/Keywords: Optimization; Convex; Interpolation; Shepard's method; Linear constraints; Quadratic programming

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APA (6^th Edition):

Espinoza, F. (2012). A New Interpolation Approach for Linearly Constrained Convex Optimization. (Thesis). King Abdullah University of Science and Technology. Retrieved from http://hdl.handle.net/10754/244891

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Espinoza, Francisco. “A New Interpolation Approach for Linearly Constrained Convex Optimization.” 2012. Thesis, King Abdullah University of Science and Technology. Accessed April 17, 2021. http://hdl.handle.net/10754/244891.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Espinoza, Francisco. “A New Interpolation Approach for Linearly Constrained Convex Optimization.” 2012. Web. 17 Apr 2021.

Vancouver:

Espinoza F. A New Interpolation Approach for Linearly Constrained Convex Optimization. [Internet] [Thesis]. King Abdullah University of Science and Technology; 2012. [cited 2021 Apr 17]. Available from: http://hdl.handle.net/10754/244891.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Espinoza F. A New Interpolation Approach for Linearly Constrained Convex Optimization. [Thesis]. King Abdullah University of Science and Technology; 2012. Available from: http://hdl.handle.net/10754/244891

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

King Abdullah University of Science and Technology

2. Hadjtaieb, Amir. PERFORMANCE ANALYSIS OF ARQ AND HYBRID ARQ OVER SINGLE-HOP, DUAL-HOP, AND MULTIBRANCH DUAL-HOP NETWORKS.

Degree: Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division, 2014, King Abdullah University of Science and Technology

URL: http://hdl.handle.net/10754/317233

► During the last decade, relay networks have attracted a lot of interest due to their numerous benefits. The relaying technique allows extending the coverage zone… (more)

▼ During the last decade, relay networks have attracted a lot of interest due to their numerous benefits. The relaying technique allows extending the coverage zone of wireless networks and offers a higher reliability for communication systems. The performance of relay networks can be improved further by the use of automatic repeat request (ARQ) and hybrid automatic repeat request (HARQ) techniques. ARQ and HARQ are retransmission mechanisms that ensure a good quality of service even in absence of channel state information at the transmitter. We, firstly, study the spectral and energy efficiency of ARQ in Nakagami-m block-fading channels. We maximize both spectral efficiency and energy efficiency with respect to the transmitted power. We derive exact expressions as well as compact and tight approximation for the solutions of these problems. Our analysis shows that the two problems of maximizing spectral efficiency and energy efficiency with respect to the transmitted power are completely different and give different solutions. Additionally, operating with a power that maximizes energy efficiency can lead to a significant drop in the spectral efficiency, and vice versa. Next, we consider a three node relay network comprising a source, a relay, and a destination. The source transmits the message to the destination using HARQ with incremental redundancy (IR). The relay overhears the transmitted message, amplifies it using a variable gain amplifier, and then forwards the message to the destination. This latter combines both the source and the relay message and tries to decode the information. In case of decoding failure, the destination sends a negative acknowledgement. A new replica of the message containing new parity bits is then transmitted in the subsequent HARQ round. This process continues until successful decoding occurs at the destination or a maximum number M of rounds is reached. We study the performance of HARQ-IR over the considered relay channel from an information theoretic perspective. We derive exact expressions and bounds for the information outage probability, the average number of transmissions, and the average transmission rate. Moreover, we evaluate the delay experienced by Poisson arriving packets over the considered relay network. We also provide analytical expressions for the expected waiting time, the sojourn time, and the energy efficiency. The derived exact expressions are validated by Monte Carlo simulations. Finally, we consider a relay network consisting of a source, K relays, and a destination. The source transmits a message to the destination using HARQ-IR. We study the performance of HARQ-IR over dualhop multibranch amplify-and-forward relay channels. We derive exact expression for outage probability of the considered network. We investigate the benefit of relaying and the effect of changing the rate and the maximum number M of rounds on the outage probability. Advisors/Committee Members: Alouini, Mohamed-Slim (advisor), Claudel, Christian G. (committee member), Turkiyyah, George (committee member).

Subjects/Keywords: Performance Analysis; Automatic Repeat request; Hybrid Automatic Repeat Request; Dual-Hop; Multibranch Dual-Hop; Energy Efficiency

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APA (6^th Edition):

Hadjtaieb, A. (2014). PERFORMANCE ANALYSIS OF ARQ AND HYBRID ARQ OVER SINGLE-HOP, DUAL-HOP, AND MULTIBRANCH DUAL-HOP NETWORKS. (Thesis). King Abdullah University of Science and Technology. Retrieved from http://hdl.handle.net/10754/317233

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Hadjtaieb, Amir. “PERFORMANCE ANALYSIS OF ARQ AND HYBRID ARQ OVER SINGLE-HOP, DUAL-HOP, AND MULTIBRANCH DUAL-HOP NETWORKS.” 2014. Thesis, King Abdullah University of Science and Technology. Accessed April 17, 2021. http://hdl.handle.net/10754/317233.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Hadjtaieb, Amir. “PERFORMANCE ANALYSIS OF ARQ AND HYBRID ARQ OVER SINGLE-HOP, DUAL-HOP, AND MULTIBRANCH DUAL-HOP NETWORKS.” 2014. Web. 17 Apr 2021.

Vancouver:

Hadjtaieb A. PERFORMANCE ANALYSIS OF ARQ AND HYBRID ARQ OVER SINGLE-HOP, DUAL-HOP, AND MULTIBRANCH DUAL-HOP NETWORKS. [Internet] [Thesis]. King Abdullah University of Science and Technology; 2014. [cited 2021 Apr 17]. Available from: http://hdl.handle.net/10754/317233.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Hadjtaieb A. PERFORMANCE ANALYSIS OF ARQ AND HYBRID ARQ OVER SINGLE-HOP, DUAL-HOP, AND MULTIBRANCH DUAL-HOP NETWORKS. [Thesis]. King Abdullah University of Science and Technology; 2014. Available from: http://hdl.handle.net/10754/317233

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

King Abdullah University of Science and Technology

3. Lipor, John. MIMO Radar Transceiver Design for High Signal-to-Interference-Plus-Noise Ratio.

Degree: Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division, 2013, King Abdullah University of Science and Technology

URL: http://hdl.handle.net/10754/291103

► Multiple-input multiple-output (MIMO) radar employs orthogonal or partially correlated transmit signals to achieve performance benefits over its phased-array counterpart. It has been shown that MIMO… (more)

▼ Multiple-input multiple-output (MIMO) radar employs orthogonal or partially correlated transmit signals to achieve performance benefits over its phased-array counterpart. It has been shown that MIMO radar can achieve greater spatial resolution, improved signal-to-noise ratio (SNR) and target localization, and greater clutter resolution using space-time adaptive processing (STAP). This thesis explores various methods to improve the signal-to-interference-plus-noise ratio (SINR) via transmit and receive beamforming. In MIMO radar settings, it is often desirable to transmit power only to a given location or set of locations defined by a beampattern. Current methods involve a two- step process of designing the transmit covariance matrix R via iterative solutions and then using R to generate waveforms that fulfill practical constraints such as having a constant-envelope or drawing from a finite alphabet. In this document, a closed- form method to design R is proposed that utilizes the discrete Fourier transform (DFT) coefficients and Toeplitz matrices. The resulting covariance matrix fulfills the practical constraints such as positive semidefiniteness and the uniform elemental power constraint and provides performance similar to that of iterative methods, which require a much greater computation time. Next, a transmit architecture is presented  that exploits the orthogonality of frequencies at discrete DFT values to transmit a sum of orthogonal signals from each antenna. The resulting waveforms provide a lower mean-square error than current methods at a much lower computational cost, and a simulated detection scenario demonstrates the performance advantages achieved. It is also desirable to receive signal power only from a given set of directions defined by a beampattern. In a later chapter of this document, the problem of receive beampattern matching is formulated and three solutions to this problem are demonstrated. We show that partitioning the received data vector into subvectors and then multiplying each subvector with its corresponding weight vector can improve performance and reduce the length of the data vector. Simulation results show that all methods are capable of matching a desired beampattern. Signal-to-interference- plus-noise ratio (SINR) calculations demonstrate a significant improvement over the unaltered MIMO case. Advisors/Committee Members: Alouini, Mohamed-Slim (advisor), Alouini, Mohamed-Slim (committee member), Sultan Salem, Ahmed Kamal (committee member), Turkiyyah, George (committee member).

Subjects/Keywords: MIMO Radar; Waveform Design; Beamforming; DFT

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Lipor, J. (2013). MIMO Radar Transceiver Design for High Signal-to-Interference-Plus-Noise Ratio. (Thesis). King Abdullah University of Science and Technology. Retrieved from http://hdl.handle.net/10754/291103

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Lipor, John. “MIMO Radar Transceiver Design for High Signal-to-Interference-Plus-Noise Ratio.” 2013. Thesis, King Abdullah University of Science and Technology. Accessed April 17, 2021. http://hdl.handle.net/10754/291103.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Lipor, John. “MIMO Radar Transceiver Design for High Signal-to-Interference-Plus-Noise Ratio.” 2013. Web. 17 Apr 2021.

Vancouver:

Lipor J. MIMO Radar Transceiver Design for High Signal-to-Interference-Plus-Noise Ratio. [Internet] [Thesis]. King Abdullah University of Science and Technology; 2013. [cited 2021 Apr 17]. Available from: http://hdl.handle.net/10754/291103.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Lipor J. MIMO Radar Transceiver Design for High Signal-to-Interference-Plus-Noise Ratio. [Thesis]. King Abdullah University of Science and Technology; 2013. Available from: http://hdl.handle.net/10754/291103

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

King Abdullah University of Science and Technology

4. Moubayed, Abdallah J. Collaborative Multi-Layer Network Coding For Hybrid Cellular Cognitive Radio Networks.

Degree: Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division, 2014, King Abdullah University of Science and Technology

URL: http://hdl.handle.net/10754/316697

► In this thesis, as an extension to [1], we propose a prioritized multi-layer network coding scheme for collaborative packet recovery in hybrid (interweave and underlay)… (more)

Subjects/Keywords: Cognitive Radio; Network Coding; Fractional Cooperation

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Moubayed, A. J. (2014). Collaborative Multi-Layer Network Coding For Hybrid Cellular Cognitive Radio Networks. (Thesis). King Abdullah University of Science and Technology. Retrieved from http://hdl.handle.net/10754/316697

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Moubayed, Abdallah J. “Collaborative Multi-Layer Network Coding For Hybrid Cellular Cognitive Radio Networks.” 2014. Thesis, King Abdullah University of Science and Technology. Accessed April 17, 2021. http://hdl.handle.net/10754/316697.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Moubayed, Abdallah J. “Collaborative Multi-Layer Network Coding For Hybrid Cellular Cognitive Radio Networks.” 2014. Web. 17 Apr 2021.

Vancouver:

Moubayed AJ. Collaborative Multi-Layer Network Coding For Hybrid Cellular Cognitive Radio Networks. [Internet] [Thesis]. King Abdullah University of Science and Technology; 2014. [cited 2021 Apr 17]. Available from: http://hdl.handle.net/10754/316697.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Moubayed AJ. Collaborative Multi-Layer Network Coding For Hybrid Cellular Cognitive Radio Networks. [Thesis]. King Abdullah University of Science and Technology; 2014. Available from: http://hdl.handle.net/10754/316697

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

King Abdullah University of Science and Technology

5. Chavez Chavez, Gustavo Ivan. Robust and scalable hierarchical matrix-based fast direct solver and preconditioner for the numerical solution of elliptic partial differential equations.

Degree: Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division, 2017, King Abdullah University of Science and Technology

URL: http://hdl.handle.net/10754/625172

► This dissertation introduces a novel fast direct solver and preconditioner for the solution of block tridiagonal linear systems that arise from the discretization of elliptic… (more)

▼ This dissertation introduces a novel fast direct solver and preconditioner for the solution of block tridiagonal linear systems that arise from the discretization of elliptic partial differential equations on a Cartesian product mesh, such as the variable-coefficient Poisson equation, the convection-diffusion equation, and the wave Helmholtz equation in heterogeneous media. The algorithm extends the traditional cyclic reduction method with hierarchical matrix techniques. The resulting method exposes substantial concurrency, and its arithmetic operations and memory consumption grow only log-linearly with problem size, assuming bounded rank of off-diagonal matrix blocks, even for problems with arbitrary coefficient structure. The method can be used as a standalone direct solver with tunable accuracy, or as a black-box preconditioner in conjunction with Krylov methods. The challenges that distinguish this work from other thrusts in this active field are the hybrid distributed-shared parallelism that can demonstrate the algorithm at large-scale, full three-dimensionality, and the three stressors of the current state-of-the-art multigrid technology: high wavenumber Helmholtz (indefiniteness), high Reynolds convection (nonsymmetry), and high contrast diffusion (inhomogeneity). Numerical experiments corroborate the robustness, accuracy, and complexity claims and provide a baseline of the performance and memory footprint by comparisons with competing approaches such as the multigrid solver hypre, and the STRUMPACK implementation of the multifrontal factorization with hierarchically semi-separable matrices. The companion implementation can utilize many thousands of cores of Shaheen, KAUST's Haswell-based Cray XC-40 supercomputer, and compares favorably with other implementations of hierarchical solvers in terms of time-to-solution and memory consumption. Advisors/Committee Members: Keyes, David E. (advisor), Moshkov, Mikhail (committee member), Ketcheson, David I. (committee member), Turkiyyah, George (committee member), Huang, Jingfang (committee member).

Subjects/Keywords: hierarchical matrices; cyclic reduction; fast solvers; Direct solvers; preconditioning; Parallel Computing

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Chavez Chavez, G. I. (2017). Robust and scalable hierarchical matrix-based fast direct solver and preconditioner for the numerical solution of elliptic partial differential equations. (Thesis). King Abdullah University of Science and Technology. Retrieved from http://hdl.handle.net/10754/625172

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Chavez Chavez, Gustavo Ivan. “Robust and scalable hierarchical matrix-based fast direct solver and preconditioner for the numerical solution of elliptic partial differential equations.” 2017. Thesis, King Abdullah University of Science and Technology. Accessed April 17, 2021. http://hdl.handle.net/10754/625172.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Chavez Chavez, Gustavo Ivan. “Robust and scalable hierarchical matrix-based fast direct solver and preconditioner for the numerical solution of elliptic partial differential equations.” 2017. Web. 17 Apr 2021.

Vancouver:

Chavez Chavez GI. Robust and scalable hierarchical matrix-based fast direct solver and preconditioner for the numerical solution of elliptic partial differential equations. [Internet] [Thesis]. King Abdullah University of Science and Technology; 2017. [cited 2021 Apr 17]. Available from: http://hdl.handle.net/10754/625172.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Chavez Chavez GI. Robust and scalable hierarchical matrix-based fast direct solver and preconditioner for the numerical solution of elliptic partial differential equations. [Thesis]. King Abdullah University of Science and Technology; 2017. Available from: http://hdl.handle.net/10754/625172

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

King Abdullah University of Science and Technology

6. Boukaram, Wagih Halim. Hierarchical Matrix Operations on GPUs.

Degree: Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division, 2020, King Abdullah University of Science and Technology

URL: http://hdl.handle.net/10754/662664

► Large dense matrices are ubiquitous in scientific computing, arising from the discretization of integral operators associated with elliptic pdes, Schur complement methods, covariances in spatial… (more)

▼ Large dense matrices are ubiquitous in scientific computing, arising from the discretization of integral operators associated with elliptic pdes, Schur complement methods, covariances in spatial statistics, kernel-based machine learning, and numerical optimization problems. Hierarchical matrices are an efficient way for storing the dense matrices of very large dimension that appear in these and related settings. They exploit the fact that the underlying matrices, while formally dense, are data sparse. They have a structure consisting of blocks many of which can be well-approximated by low rank factorizations. A hierarchical organization of the blocks avoids superlinear growth in memory requirements to store n × n dense matrices in a scalable manner, requiring O(n) units of storage with a constant depending on a representative rank k for the low rank blocks. The asymptotically optimal storage requirement of the resulting hierarchical matrices is a critical advantage, particularly in extreme computing environments, characterized by low memory per processing core. The challenge then becomes to develop the parallel linear algebra operations that can be performed directly on this compressed representation. In this dissertation, I implement a set of hierarchical basic linear algebra subroutines (HBLAS) optimized for GPUs, including hierarchical matrix vector multiplication, orthogonalization, compression, low rank updates, and matrix multiplication. I develop a library of open source batched kernel operations previously missing on GPUs for the high performance implementation of the H2 operations, while relying wherever possible on existing open source and vendor kernels to ride future improvements in the technology. Fast marshaling routines extract the batch operation data from an efficient representation of the trees that compose the hierarchical matrices. The methods developed for GPUs extend to CPUs using the same code base with simple abstractions around the batched routine execution. To demonstrate the scalability of the hierarchical operations I implement a distributed memory multi-GPU hierarchical matrix vector product that focuses on reducing communication volume and hiding communication overhead and areas of low GPU utilization using low priority streams. Two demonstrations involving Hessians of inverse problems governed by pdes and space-fractional diffusion equations show the effectiveness of the hierarchical operations in realistic applications. Advisors/Committee Members: Keyes, David E. (advisor), Ketcheson, David I. (committee member), Hadwiger, Markus (committee member), Turkiyyah, George (committee member), Darve, Eric F. (committee member).

Subjects/Keywords: Hierarchical Matrices; Linear Algebra; GPU; Batched Algorithms; Matrix Compression; Randomized Algorithms

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Boukaram, W. H. (2020). Hierarchical Matrix Operations on GPUs. (Thesis). King Abdullah University of Science and Technology. Retrieved from http://hdl.handle.net/10754/662664

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Boukaram, Wagih Halim. “Hierarchical Matrix Operations on GPUs.” 2020. Thesis, King Abdullah University of Science and Technology. Accessed April 17, 2021. http://hdl.handle.net/10754/662664.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Boukaram, Wagih Halim. “Hierarchical Matrix Operations on GPUs.” 2020. Web. 17 Apr 2021.

Vancouver:

Boukaram WH. Hierarchical Matrix Operations on GPUs. [Internet] [Thesis]. King Abdullah University of Science and Technology; 2020. [cited 2021 Apr 17]. Available from: http://hdl.handle.net/10754/662664.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Boukaram WH. Hierarchical Matrix Operations on GPUs. [Thesis]. King Abdullah University of Science and Technology; 2020. Available from: http://hdl.handle.net/10754/662664

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

7. Dutta, Gaurav. Wave-equation Q tomography and least-squares migration.

Degree: Physical Science and Engineering (PSE) Division, 2016, King Abdullah University of Science and Technology

URL: http://hdl.handle.net/10754/605856

► This thesis designs new methods for Q tomography and Q-compensated prestack depth migration when the recorded seismic data suffer from strong attenuation. A motivation of… (more)

▼ This thesis designs new methods for Q tomography and Q-compensated prestack depth migration when the recorded seismic data suffer from strong attenuation. A motivation of this work is that the presence of gas clouds or mud channels in overburden structures leads to the distortion of amplitudes and phases in seismic waves propagating inside the earth. If the attenuation parameter Q is very strong, i.e., Q<30, ignoring the anelastic effects in imaging can lead to dimming of migration amplitudes and loss of resolution. This, in turn, adversely affects the ability to accurately predict reservoir properties below such layers. To mitigate this problem, I first develop an anelastic least-squares reverse time migration (Q-LSRTM) technique. I reformulate the conventional acoustic least-squares migration problem as a viscoacoustic linearized inversion problem. Using linearized viscoacoustic modeling and adjoint operators during the least-squares iterations, I show with numerical tests that Q-LSRTM can compensate for the amplitude loss and produce images with better balanced amplitudes than conventional migration. To estimate the background Q model that can be used for any Q-compensating migration algorithm, I then develop a wave-equation based optimization method that inverts for the subsurface Q distribution by minimizing a skeletonized misfit function ε. Here, ε is the sum of the squared differences between the observed and the predicted peak/centroid-frequency shifts of the early-arrivals. Through numerical tests on synthetic and field data, I show that noticeable improvements in the migration image quality can be obtained from Q models inverted using wave-equation Q tomography. A key feature of skeletonized inversion is that it is much less likely to get stuck in a local minimum than a standard waveform inversion method. Finally, I develop a preconditioning technique for least-squares migration using a directional Gabor-based preconditioning approach for isotropic, anisotropic or anelastic least-squares migration. During the least-squares iterations, I impose sparsity constraints on the inverted reflectivity model in the local Radon domain. The forward and the inverse mapping of the reflectivity to the local Radon domain is done through 3D Fourier-based discrete Radon transform operators. Using numerical tests on synthetic and 3D field data, I demonstrate that the proposed preconditioning approach can discriminate against artifacts in the image resulting from irregular or insufficient acquisition and can produce images with improved signal-to-noise ratio when compared with standard migration. Advisors/Committee Members: Schuster, Gerard T. (advisor), Williamson, Paul (committee member), Alkhalifah, Tariq Ali (committee member), Peter, Daniel (committee member), Wu, Ying (committee member), Turkiyyah, George M. (committee member).

Subjects/Keywords: Attenuation; Tomography; Least-squares; RTM; Q-compensation

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APA (6^th Edition):

Dutta, G. (2016). Wave-equation Q tomography and least-squares migration. (Thesis). King Abdullah University of Science and Technology. Retrieved from http://hdl.handle.net/10754/605856

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Dutta, Gaurav. “Wave-equation Q tomography and least-squares migration.” 2016. Thesis, King Abdullah University of Science and Technology. Accessed April 17, 2021. http://hdl.handle.net/10754/605856.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Dutta, Gaurav. “Wave-equation Q tomography and least-squares migration.” 2016. Web. 17 Apr 2021.

Vancouver:

Dutta G. Wave-equation Q tomography and least-squares migration. [Internet] [Thesis]. King Abdullah University of Science and Technology; 2016. [cited 2021 Apr 17]. Available from: http://hdl.handle.net/10754/605856.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Dutta G. Wave-equation Q tomography and least-squares migration. [Thesis]. King Abdullah University of Science and Technology; 2016. Available from: http://hdl.handle.net/10754/605856

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

8. Randrianantenaina, Itsikiantsoa. Energy Efficient and Performance Analysis of Multihop Wireless Communication Over Nakagami-m Fading Channel.

Degree: Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division, 2015, King Abdullah University of Science and Technology

URL: http://hdl.handle.net/10754/556544

► The concept of multihop communications (where the source communicates with the destination via many intermediate nodes) has been revisited and adapted to mitigate wireless channel… (more)

Subjects/Keywords: Multihop communications; Nakagami-m fading; Amplify and Forward; Decode and Forward; Consumption Factor; MRC

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APA (6^th Edition):

Randrianantenaina, I. (2015). Energy Efficient and Performance Analysis of Multihop Wireless Communication Over Nakagami-m Fading Channel. (Thesis). King Abdullah University of Science and Technology. Retrieved from http://hdl.handle.net/10754/556544

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Randrianantenaina, Itsikiantsoa. “Energy Efficient and Performance Analysis of Multihop Wireless Communication Over Nakagami-m Fading Channel.” 2015. Thesis, King Abdullah University of Science and Technology. Accessed April 17, 2021. http://hdl.handle.net/10754/556544.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Randrianantenaina, Itsikiantsoa. “Energy Efficient and Performance Analysis of Multihop Wireless Communication Over Nakagami-m Fading Channel.” 2015. Web. 17 Apr 2021.

Vancouver:

Randrianantenaina I. Energy Efficient and Performance Analysis of Multihop Wireless Communication Over Nakagami-m Fading Channel. [Internet] [Thesis]. King Abdullah University of Science and Technology; 2015. [cited 2021 Apr 17]. Available from: http://hdl.handle.net/10754/556544.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Randrianantenaina I. Energy Efficient and Performance Analysis of Multihop Wireless Communication Over Nakagami-m Fading Channel. [Thesis]. King Abdullah University of Science and Technology; 2015. Available from: http://hdl.handle.net/10754/556544

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

9. Ali, Konpal S. On Lattice Sequential Decoding for Large MIMO Systems.

Degree: Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division, 2014, King Abdullah University of Science and Technology

URL: http://hdl.handle.net/10754/316732

► Due to their ability to provide high data rates, Multiple-Input Multiple-Output (MIMO) wireless communication systems have become increasingly popular. Decoding of these systems with acceptable… (more)

▼ Due to their ability to provide high data rates, Multiple-Input Multiple-Output (MIMO) wireless communication systems have become increasingly popular. Decoding of these systems with acceptable error performance is computationally very demanding. In the case of large overdetermined MIMO systems, we employ the Sequential Decoder using the Fano Algorithm. A parameter called the bias is varied to attain different performance-complexity trade-offs. Low values of the bias result in excellent performance but at the expense of high complexity and vice versa for higher bias values. We attempt to bound the error by bounding the bias, using the minimum distance of a lattice. Also, a particular trend is observed with increasing SNR: a region of low complexity and high error, followed by a region of high complexity and error falling, and finally a region of low complexity and low error. For lower bias values, the stages of the trend are incurred at lower SNR than for higher bias values. This has the important implication that a low enough bias value, at low to moderate SNR, can result in low error and low complexity even for large MIMO systems. Our work is compared against Lattice Reduction (LR) aided Linear Decoders (LDs). Another impressive observation for low bias values that satisfy the error bound is that the Sequential Decoder's error is seen to fall with increasing system size, while it grows for the LR-aided LDs. For the case of large underdetermined MIMO systems, Sequential Decoding with two preprocessing schemes is proposed – 1) Minimum Mean Square Error Generalized Decision Feedback Equalization (MMSE-GDFE) preprocessing 2) MMSE-GDFE preprocessing, followed by Lattice Reduction and Greedy Ordering. Our work is compared against previous work which employs Sphere Decoding preprocessed using MMSE-GDFE, Lattice Reduction and Greedy Ordering. For the case of large systems, this results in high complexity and difficulty in choosing the sphere radius. Our schemes, particularly 2), perform better in terms of complexity and are able to achieve almost the same error curves, depending on the bias used. Advisors/Committee Members: Alouini, Mohamed-Slim (advisor), Al-Naffouri, Tareq Y. (committee member), Sultan Salem, Ahmed Kamal (committee member), Turkiyyah, George (committee member).

Subjects/Keywords: Lattice; MIMO; Overdetermined; Underdetermined; Sequential-decodes; Bias

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APA (6^th Edition):

Ali, K. S. (2014). On Lattice Sequential Decoding for Large MIMO Systems. (Thesis). King Abdullah University of Science and Technology. Retrieved from http://hdl.handle.net/10754/316732

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Ali, Konpal S. “On Lattice Sequential Decoding for Large MIMO Systems.” 2014. Thesis, King Abdullah University of Science and Technology. Accessed April 17, 2021. http://hdl.handle.net/10754/316732.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Ali, Konpal S. “On Lattice Sequential Decoding for Large MIMO Systems.” 2014. Web. 17 Apr 2021.

Vancouver:

Ali KS. On Lattice Sequential Decoding for Large MIMO Systems. [Internet] [Thesis]. King Abdullah University of Science and Technology; 2014. [cited 2021 Apr 17]. Available from: http://hdl.handle.net/10754/316732.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Ali KS. On Lattice Sequential Decoding for Large MIMO Systems. [Thesis]. King Abdullah University of Science and Technology; 2014. Available from: http://hdl.handle.net/10754/316732

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

10. Sboui, Lokman. On the Capacity of Underlay Cognitive Radio Systems.

Degree: Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division, 2013, King Abdullah University of Science and Technology

URL: http://hdl.handle.net/10754/291102

► Due to the scarcity of frequency spectrum in view of the evolution of wireless communication technologies, the cognitive radio (CR) concept has been introduced to… (more)

▼ Due to the scarcity of frequency spectrum in view of the evolution of wireless communication technologies, the cognitive radio (CR) concept has been introduced to efficiently exploit the available spectrum. This concept consists in introducing unlicensed/secondary users (SU’s) in existing networks to share the spectrum of licensed/primary users (PU’s) without harming primary communications hence the name of “spectrum sharing” technique. We study in this dissertation, the capacity and the achievable rate of the secondary user within various communication settings. We, firstly, investigate the capacity of the (SU’s) at low power regime for Nakagami fading channels and present closed form of the capacity under various types of interference and/or power constraints. We explicitly characterize two regimes where either the interference constraint or the power constraint dictates the optimal power profile. Our framework also highlights the effects of different fading parameters on the secondary link ergodic capacity. Interestingly, we show that the low power regime analysis provides a specific insight on the capacity behavior of CR that has not been reported by previous studies. Next, we determine the spectral efficiency gain of an uplink CR Multi-Input Multi- Output (MIMO) system in which the SU is allowed to share the spectrum with the PU using a specific precoding scheme to communicate with a common receiver. Applied to Rayleigh fading channels, we show, through numerical results, that our proposed scheme enhances considerably the cognitive achievable rate. For instance, in case of a perfect detection of the PU signal, after applying Successive Interference Cancellation (SIC), the CR rate remains non-zero for high Signal to Noise Ratio (SNR) which is usually impossible when we only use space alignment technique. In addition, we show that the rate gain is proportional to the allowed interference threshold by providing a fixed rate even in the high SNR range. Finally, we study the impact of the broadcast approach and multi-layer coding on the throughput of CR systems for general fading channels. And we found that at the absence of the channel state information(CSI), we show that this improvement could be almost reached by 2-Layers coding. Then, we introduce a quantized CSI policy and highlight its improvement in terms of throughput before we study the rate when BA with quantized CSI is adopted. Numerical results show that the improvement of the additional layers is decreasing as the number of quantized regions increases. Advisors/Committee Members: Alouini, Mohamed-Slim (advisor), Alouini, Mohamed-Slim (committee member), Rezki, Zouheir (committee member), Sultan Salem, Ahmed Kamal (committee member), Turkiyyah, George (committee member).

Subjects/Keywords: Cognitive Radio; Capacity/Rate; Low SNR; Broadcast Approach; Underlay Systems

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Sboui, L. (2013). On the Capacity of Underlay Cognitive Radio Systems. (Thesis). King Abdullah University of Science and Technology. Retrieved from http://hdl.handle.net/10754/291102

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Sboui, Lokman. “On the Capacity of Underlay Cognitive Radio Systems.” 2013. Thesis, King Abdullah University of Science and Technology. Accessed April 17, 2021. http://hdl.handle.net/10754/291102.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Sboui, Lokman. “On the Capacity of Underlay Cognitive Radio Systems.” 2013. Web. 17 Apr 2021.

Vancouver:

Sboui L. On the Capacity of Underlay Cognitive Radio Systems. [Internet] [Thesis]. King Abdullah University of Science and Technology; 2013. [cited 2021 Apr 17]. Available from: http://hdl.handle.net/10754/291102.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Sboui L. On the Capacity of Underlay Cognitive Radio Systems. [Thesis]. King Abdullah University of Science and Technology; 2013. Available from: http://hdl.handle.net/10754/291102

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

King Abdullah University of Science and Technology

11. Solares, Jose. Optimal Power Allocation of a Wireless Sensor Node under Different Rate Constraints.

Degree: Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division, 2011, King Abdullah University of Science and Technology

URL: http://hdl.handle.net/10754/209413

► Wireless sensor networks consist of the placement of sensors over a broad area in order to acquire data. Depending on the application, different design criteria… (more)

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Solares, J. (2011). Optimal Power Allocation of a Wireless Sensor Node under Different Rate Constraints. (Thesis). King Abdullah University of Science and Technology. Retrieved from http://hdl.handle.net/10754/209413

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Solares, Jose. “Optimal Power Allocation of a Wireless Sensor Node under Different Rate Constraints.” 2011. Thesis, King Abdullah University of Science and Technology. Accessed April 17, 2021. http://hdl.handle.net/10754/209413.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Solares, Jose. “Optimal Power Allocation of a Wireless Sensor Node under Different Rate Constraints.” 2011. Web. 17 Apr 2021.

Vancouver:

Solares J. Optimal Power Allocation of a Wireless Sensor Node under Different Rate Constraints. [Internet] [Thesis]. King Abdullah University of Science and Technology; 2011. [cited 2021 Apr 17]. Available from: http://hdl.handle.net/10754/209413.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Solares J. Optimal Power Allocation of a Wireless Sensor Node under Different Rate Constraints. [Thesis]. King Abdullah University of Science and Technology; 2011. Available from: http://hdl.handle.net/10754/209413

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

King Abdullah University of Science and Technology

12. Luna, Manuel. Nonlinear Wave Propagation and Solitary Wave Formation in Two-Dimensional Heterogeneous Media.

Degree: Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division, 2011, King Abdullah University of Science and Technology

URL: http://hdl.handle.net/10754/209415

► Solitary wave formation is a well studied nonlinear phenomenon arising in propagation of dispersive nonlinear waves under suitable conditions. In non-homogeneous materials, dispersion may happen… (more)

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Luna, M. (2011). Nonlinear Wave Propagation and Solitary Wave Formation in Two-Dimensional Heterogeneous Media. (Thesis). King Abdullah University of Science and Technology. Retrieved from http://hdl.handle.net/10754/209415

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Luna, Manuel. “Nonlinear Wave Propagation and Solitary Wave Formation in Two-Dimensional Heterogeneous Media.” 2011. Thesis, King Abdullah University of Science and Technology. Accessed April 17, 2021. http://hdl.handle.net/10754/209415.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Luna, Manuel. “Nonlinear Wave Propagation and Solitary Wave Formation in Two-Dimensional Heterogeneous Media.” 2011. Web. 17 Apr 2021.

Vancouver:

Luna M. Nonlinear Wave Propagation and Solitary Wave Formation in Two-Dimensional Heterogeneous Media. [Internet] [Thesis]. King Abdullah University of Science and Technology; 2011. [cited 2021 Apr 17]. Available from: http://hdl.handle.net/10754/209415.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Luna M. Nonlinear Wave Propagation and Solitary Wave Formation in Two-Dimensional Heterogeneous Media. [Thesis]. King Abdullah University of Science and Technology; 2011. Available from: http://hdl.handle.net/10754/209415

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Open Access Theses and Dissertations