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Electrical and Computer Engineering Faculty Research & Creative Works

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Articles 1591 - 1620 of 3518

Full-Text Articles in Engineering

Parametric Study On The Effect Of Asymmetry In Multi-Channel Differential Signaling, Ki Jin Han, Xiaoxiong Gu, Young H. Kwark, Zhenwei Yu, Dazhao Liu, Bruce Archambeault, Samuel R. Connor, Jun Fan Oct 2011

Parametric Study On The Effect Of Asymmetry In Multi-Channel Differential Signaling, Ki Jin Han, Xiaoxiong Gu, Young H. Kwark, Zhenwei Yu, Dazhao Liu, Bruce Archambeault, Samuel R. Connor, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

The effects of geometric asymmetry on the electrical performance of multi-channel differential signaling in printed circuit boards are investigated in this paper. the asymmetry, which is the origin of noise coupled through mode conversion, is difficult to control in real channel structures, where a large number of vias and traces are populated. Supported by an efficient parametric simulation tool, this paper presents the effects of the asymmetry on mode conversion and differential mode crosstalk in real multi-channel structures. This extensive parametric study was used to define design guidelines to suppress this noise coupling by adding ground vias in strategic locations. …

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Optimizing Decoupling Capacitor Placement To Reduce Effective Inductance, Bruce Archambeault, Jingook Kim, Sam Connor, Jun Fan Oct 2011

Optimizing Decoupling Capacitor Placement To Reduce Effective Inductance, Bruce Archambeault, Jingook Kim, Sam Connor, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

Optimizing decoupling capacitor placement to ensure rapid charge delivery is discussed in this paper. Placing additional decoupling capacitors in close proximity may reduce effective inductance but this inductance is only reduced under certain conditions. © 2011 IEEE.

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Modeling And Analysis Of A Trace Referenced To A Meshed Ground Plane, Songping Wu, Hao Shi, Matthew Herndon, Bill Cornelius, Matt Halligan, Jun Fan Oct 2011

Modeling And Analysis Of A Trace Referenced To A Meshed Ground Plane, Songping Wu, Hao Shi, Matthew Herndon, Bill Cornelius, Matt Halligan, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

Meshed planes are used in today's flexible PCB designs, and due to their non-homogeneous nature, Modeling of nearby interconnects increases in complexity. in this paper, a method to evaluate the effective characteristic impedance of a trace referenced to a meshed plane is proposed that is simpler and optimization based. the effective impedance and the per-unit-length parameters of the line were associated with the meshed plane periodical patterns as well as trace relative locations. a systematic study was performed to reveal the essential relationship between the meshed plane geometric parameters and the trace characteristics. © 2011 IEEE.

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Measurement Of Multiple Switching Current Components Through A Bulk Decoupling Capacitor Using A Lab-Made Low-Cost Current Probe, Liang Li, Jingook Kim, Hanfeng Wang, Songping Wu, Yuzo Takita, Hayato Takeuchi, Kenji Araki, Jun Fan Oct 2011

Measurement Of Multiple Switching Current Components Through A Bulk Decoupling Capacitor Using A Lab-Made Low-Cost Current Probe, Liang Li, Jingook Kim, Hanfeng Wang, Songping Wu, Yuzo Takita, Hayato Takeuchi, Kenji Araki, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a measurement-Based data-processing approach to obtain parameters of multiple current components through a bulk decoupling capacitor for power integrity studies. a lab-made low-cost current probe is developed to measure the induced voltage due to the time-varying switching current. Then, a post data-processing procedure is introduced to separate and obtain the parameters of multiple current components. the results obtained by the proposed method are validated with other approaches. © 2011 IEEE.

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Near-Field H To E Transformation Using Plane Wave Spectrum Theory, Zhenwei Yu, Yaojiang Zhang, Soji Sajuyigbe, R. Camacho, Jason A. Mix, Kevin Slattery, Matthew S. Halligan, Jun Fan Oct 2011

Near-Field H To E Transformation Using Plane Wave Spectrum Theory, Zhenwei Yu, Yaojiang Zhang, Soji Sajuyigbe, R. Camacho, Jason A. Mix, Kevin Slattery, Matthew S. Halligan, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

Near-field measurements are widely used to indicate the radiation from integrated circuits (IC). to minimize the number of field components measured in a near-field scan, it is necessary to calculate the electric field from magnetic field or vice versa. in this paper, a method based on plane wave spectrum theory is proposed to perform the H to E transformation, and a filtering technique is proposed to address the noise problem in the calculation. a simple active circuit in a 3-D full-wave simulation tool is used to validate this method. This method is useful to reduce the number of field components …

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Estimation Of Crosstalk Among Multiple Stripline Traces Crossing A Split By Compressed Sensing, Tao Wang, Yiyu Shi, Songping Wu, Jun Fan Oct 2011

Estimation Of Crosstalk Among Multiple Stripline Traces Crossing A Split By Compressed Sensing, Tao Wang, Yiyu Shi, Songping Wu, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

In printed circuit board (PCB) designs, it is common to split power/ground planes into different partitions, which leads to more crosstalk among signal traces that route crossing a split. It is of general interest to develop a crosstalk model for various geometric parameters. However, the long time required to simulate the structure with any given set of geometric parameters renders general modelling approaches such as interpolation inefficient. in this paper, we develop an empirical model based upon the compressed sensing technique to characterize the crosstalk among traces as a function of geometric parameters. a good agreement between the empirical model …

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Compressed Sensing Based Analytical Modeling For Through-Silicon-Via Pairs, Tao Wang, Jingook Kim, Jun Fan, Yiyu Shi Oct 2011

Compressed Sensing Based Analytical Modeling For Through-Silicon-Via Pairs, Tao Wang, Jingook Kim, Jun Fan, Yiyu Shi

Electrical and Computer Engineering Faculty Research & Creative Works

Through-Silicon-Vias (TSVs) are the critical enabling technique for three-dimensional integrated circuits (3D ICs). While there are a few existing works in literature to model the electrical performance of TSVs, they are either for fixed geometry or in lack of accuracy. in this paper, we use compressed sensing technique to model the electrical performance of TSV pairs. Experimental results indicate that with an exceptionally small number of samples, our model has a maximum relative error of 3.94% compared with full-wave simulations over a wide range of geometry parameters and frequencies. © 2011 IEEE.

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Analysis Of Unbalanced System Efficiency With A Positive Sequence Power Flow Program, Karl Stefanski, Badrul H. Chowdhury Oct 2011

Analysis Of Unbalanced System Efficiency With A Positive Sequence Power Flow Program, Karl Stefanski, Badrul H. Chowdhury

Electrical and Computer Engineering Faculty Research & Creative Works

Most existing power flow programs assume balanced loading where the positive sequence impedances are sufficient to use. However, a more accurate approach is often required due to the increasing penetration of single-phase distributed generation sources on distribution grids which tend to introduce large imbalances. the proposed method uses a positive sequence power flow algorithm where the inputs are modified to accurately simulate an unbalanced system. the algorithm is tested on the IEEE 4-bus system and the results compared with published results. the impact of the analysis on system efficiency calculations are shown for the 4-bus system as well as for …

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Investment Payback Calculator For Distributed Generation Sources, Md Rasheduzzaman, Elizabeth Stahlman, Badrul H. Chowdhury Oct 2011

Investment Payback Calculator For Distributed Generation Sources, Md Rasheduzzaman, Elizabeth Stahlman, Badrul H. Chowdhury

Electrical and Computer Engineering Faculty Research & Creative Works

The development of a distributed generation payback calculator that can be used for different types of energy technologies such as small wind turbines, fuel cells, microturbines, solar PV and other technologies is presented. the payback calculator takes several inputs such as technology costs, expected life of the project, capacity factor, system size, customer type, and several other relevant parameters. from these inputs, the calculator computes several different outputs including the total energy produced within a year, the rate of return, total expenses, total cash flow, and the discounted payback period in years. the calculator is embedded into a website available …

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Grid Frequency And Voltage Support Using Pv Systems With Energy Storage, Ravi Bhatt, Badrul H. Chowdhury Oct 2011

Grid Frequency And Voltage Support Using Pv Systems With Energy Storage, Ravi Bhatt, Badrul H. Chowdhury

Electrical and Computer Engineering Faculty Research & Creative Works

An optimized operating scheme for a utility connected community based photovoltaic (PV) system is described. the system can participate in grid ancillary services like frequency and voltage regulation functions based on the Smart Grid framework. the proposed model comprises of a PV plant with Li-ion batteries coupled to the grid with the help of a three-phase inverter. a two-way communication between the PV plant and the grid is assumed. the PV/storage plant provides constant updates on its current kW/kVar capability, and the grid transmits the demand for specific amounts of power and for specific lengths of time. the battery charging …

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Modification Of Digital Music Files For Use In Human Temporary Threshold Shift Studies, C. G. Le Prell, Q. Yang, J. G. Harris Oct 2011

Modification Of Digital Music Files For Use In Human Temporary Threshold Shift Studies, C. G. Le Prell, Q. Yang, J. G. Harris

Electrical and Computer Engineering Faculty Research & Creative Works

An exposure that is reproducible across clinical/laboratory environments, and appealing to subjects, is described here. Digital music files are level-equated within and across songs such that playlists deliver an exposure that is consistent across time. Modified music is more pleasant to listen to than pure tones or shaped noise and closely follows music exposures subjects may normally experience. Multiple therapeutics reduce noise-induced hearing loss in animals, but human trial design is complicated by limited access to noise-exposed subject populations. The development of standard music exposure parameters for temporary threshold shift studies would allow comparison of protection across agents with real-world …

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Theoretical Capacity Analysis For Multi-Hop Backscatter Communication Networks, Aditya V. Padaki, Maciej J. Zawodniok Sep 2011

Theoretical Capacity Analysis For Multi-Hop Backscatter Communication Networks, Aditya V. Padaki, Maciej J. Zawodniok

Electrical and Computer Engineering Faculty Research & Creative Works

Traditionally wireless sensor networks (WSNs) employ active RF communication where the RF signal has to be generated at nodes, thus consuming a significant amount of energy. in contrast, employment of passive communication, where nodes backscatter a modulated version of the incident RF signal, offers great advantages including reducing the energy cost of communication. Existing example includes a traditional RFID system with active reader communicating directly with passive tags. However, the proposed approach targets future, more advanced systems that support a generic backscatter communication. However, the inherent asymmetry in communication, reliance on external source of RF signal, and limited energy storage …

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Cooperative Approaches Indicating To Capacity And Power Control For Ad Hoc Wireless Network, Liuju Wu, Maciej Jan Zawodniok Sep 2011

Cooperative Approaches Indicating To Capacity And Power Control For Ad Hoc Wireless Network, Liuju Wu, Maciej Jan Zawodniok

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, two integrated schemes for fair capacity allocation and power control for ad hoc wireless network are presented. the game theory approach is utilized to derive a collaborative update law. in the practical wireless network, a non-uniform distribution of nodes results in varying degree of interference among the network links or hops. Such varying mutual interference may lead to unfair allocation of bandwidth and result in network congestion. as a result, some links may become bottlenecks for the entire network. Hence, it is important to fairly allocate resources in the entire network. the proposed schemes aim to address …

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Development Of Optimal Controllers For A Dfig Based Wind Farm In A Smart Grid Under Variable Wind Speed Conditions, Priyam Chakravarty, Ganesh K. Venayagamoorthy Sep 2011

Development Of Optimal Controllers For A Dfig Based Wind Farm In A Smart Grid Under Variable Wind Speed Conditions, Priyam Chakravarty, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

Variations in wind speed cause different transient responses in a Doubly Fed Induction Generator (DFIG)-Based wind farm. Transients during grid disturbances, depending on controller parameters, can lead to a system collapse, especially when significant fluctuations exist in wind speed despite the presence of SmartParks (energy storage). When a fault is introduced, the variable frequency converter (VFC) is the most susceptible part in a DFIG. the VFC is controlled by a set of Proportional Integral (PI) controllers. Parameters of PI controllers are very difficult to tune using traditional methods due to nonlinearity in DFIGs and the increasing complexity of smart grids. …

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Reduced Order Modeling Of Delayed Peec Circuits, Francesco Ferranti, Michel Nakhla, Giulio Antonini, Tom Dhaene, Luc Knockaert, Albert E. Ruehli Sep 2011

Reduced Order Modeling Of Delayed Peec Circuits, Francesco Ferranti, Michel Nakhla, Giulio Antonini, Tom Dhaene, Luc Knockaert, Albert E. Ruehli

Electrical and Computer Engineering Faculty Research & Creative Works

We propose a novel model order reduction technique that is able to accurately reduce electrically large systems with delay elements, which can be described by means of neutral delayed differential equations. It is based on an adaptive multipoint expansion and model order reduction of equivalent first order systems. the neutral delayed differential formulation is preserved in the reduced model. Pertinent numerical results validate the proposed model order reduction approach. © 2011 IEEE.

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Near Optimal Control Of Mobile Robot Formations, Travis Dierks, Bryan Brenner, S. Jagannathan Sep 2011

Near Optimal Control Of Mobile Robot Formations, Travis Dierks, Bryan Brenner, S. Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, the infinite horizon optimal tracking control problem is solved online and forward-in-time for leader-follower based formation control of nonholonomic mobile robots. using the backstepping design approach, the dynamical controller inputs for the robots are approximated from nonlinear optimal control techniques in order to track the control velocities designed to keep the formation. the proposed nonlinear optimal control technique, referred to as adaptive dynamic programming, uses neural networks (NN's) to solve the optimal formation control problem in discrete-time in the presence of unknown internal dynamics and a known control coefficient matrix. All NN's are tuned online using novel …

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Achievable Rate Region Characterization Of The Mimo Broadcast Channel With Channel Distribution Information, Yongpeng Wu, Shi Jin, Xiqi Gao, Chengshan Xiao, Matthew R. Mckay Sep 2011

Achievable Rate Region Characterization Of The Mimo Broadcast Channel With Channel Distribution Information, Yongpeng Wu, Shi Jin, Xiqi Gao, Chengshan Xiao, Matthew R. Mckay

Electrical and Computer Engineering Faculty Research & Creative Works

We investigate the multiple-input multiple-output broadcast channel with channel distribution information available at the transmitter. the so-called fading-paper model is considered with Nt transmit antennas, and each user having Nr receive antennas. Near-optimal designs are proposed for the inflation factor matrix under general fading conditions, based on maximizing the approximation of linear assignment capacity. It is proved that for Nt ≤ Nr, this matrix has a similar structure and achieves a similar interference elimination effect as dirty-paper coding. Also, low complexity iterative algorithms are proposed for Nt > N r case, which yield a good choice for the inflation factor matrix …

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Linear Precoding For Relay Networks With Finite-Alphabet Constraints, Weiliang Zeng, Chengshan Xiao, Mingxi Wang, Jianhua Lu Sep 2011

Linear Precoding For Relay Networks With Finite-Alphabet Constraints, Weiliang Zeng, Chengshan Xiao, Mingxi Wang, Jianhua Lu

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, we investigate the optimal precoding scheme for relay networks with finite-alphabet constraints. We show that the previous work utilizing various design criteria to maximize either the diversity or the transmission rate with the Gaussian inputs assumption may lead to significant loss for a practical system with finite constellation set constraint. a linear precoding scheme is proposed to maximize the transmission rate, i.e., the mutual information, for relay networks. We exploit the structure of the optimal precoding matrix and develop a unified two-step iterative algorithm utilizing the theory of convex optimization and optimization on the complex Stiefel manifold. …

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Low Complexity Turbo Detection Of Coded Under-Determined Mimo Systems, Michael L. Walker, Jun Tao, Jingxian Wu, Yahong Rosa Zheng Sep 2011

Low Complexity Turbo Detection Of Coded Under-Determined Mimo Systems, Michael L. Walker, Jun Tao, Jingxian Wu, Yahong Rosa Zheng

Electrical and Computer Engineering Faculty Research & Creative Works

The turbo detection of a coded under-determined multiple-input multiple-output (UD-MIMO) system is studied in this paper. a UD-MIMO system with N transmit antennas and M < N receive antennas has more unknowns than the observations. However, most existing low complexity detectors, such as the vertical Bell Laboratories Layered Space-Time (V-BLAST) or the block decision feedback equalizer (BDFE), work only when M ≥ N. We propose a new turbo detector structure that combines the existing generalized parallel interference cancellation (GPIC) technique and a new generalized serial interference cancellation (GSIC) technique, with a soft-input soft-output (SISO) BDFE. in the first iteration, the GPIC-BDFE equalization is adopted. from the second iteration and beyond, due to the availability of the a priori soft information, the UD-MIMO system can be partitioned into multiple sub-systems by using a reliability-Based partition scheme. Then, the GSIC-BDFE equalization, which has a much lower complexity than the GPIC-BDFE equalization, can be used. Simulation results show that the new detection scheme achieves significant performance gain as the iteration progresses with a reasonable complexity. © 2011 IEEE.

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Smartpark Shock Absorbers For Wind Farms, Ganesh K. Venayagamoorthy, P. Mitra Sep 2011

Smartpark Shock Absorbers For Wind Farms, Ganesh K. Venayagamoorthy, P. Mitra

Electrical and Computer Engineering Faculty Research & Creative Works

Vehicle-to-grid power transactions will be integrated in future smart grids. This letter presents the novel idea of utilizing plug-in vehicle parking lots (SmartParks) to reduce the shock on the transmission lines connected to a wind farm caused by drastic variations in wind-power generation and to prevent the neighboring lines from overloading. the idea is demonstrated on a power system consisting of a large wind farm and six SmartParks modeled on a real-time simulator. © 2011 IEEE.

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Frequency-Domain Turbo Equalization With Soft Successive Interference Cancellation For Single Carrier Mimo Underwater Acoustic Communications, Jian Zhang, Yahong Rosa Zheng Sep 2011

Frequency-Domain Turbo Equalization With Soft Successive Interference Cancellation For Single Carrier Mimo Underwater Acoustic Communications, Jian Zhang, Yahong Rosa Zheng

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes a low-complexity frequency-domain turbo equalizer (FDTE) combined with phase rotation compensation and soft successive interference cancellation (SSIC) for single carrier multiple-input multiple-output (MIMO) underwater acoustic (UWA) communications. Different from existing time-domain turbo equalizers in MIMO UWA systems, the proposed receiver implements low-complexity turbo equalization in the frequency domain to combat severe inter-symbol interference (ISI) and employs a layered structure to cope with unbalanced MIMO channels. Soft, rather than hard, successive interference cancellation (SIC) is employed in the layered iterative turbo detection to alleviate co-channel interference (CCI), and phase compensation is utilized within the layered FDTE to mitigate …

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Smartpark As A Virtual Statcom, Pinaki Mitra, Ganesh K. Venayagamoorthy, Keith Corzine Sep 2011

Smartpark As A Virtual Statcom, Pinaki Mitra, Ganesh K. Venayagamoorthy, Keith Corzine

Electrical and Computer Engineering Faculty Research & Creative Works

Power electronic-Based FACTS devices such as STATCOMs are sometimes essential for voltage support in transmission networks. They can also be used for continuous operation of doubly fed induction generator-Based wind turbines during faults. However, these devices are quite expensive and therefore cannot be used extensively. This paper explores the potential of a low-cost solution that utilizes the reactive power and voltage support capabilities of plug-in vehicles parked in charging stations (SmartParks) so that they can behave as virtual STATCOMs. for this solution, a 12-bus multimachine power system is considered wherein one of the conventional units is replaced by a 400 …

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Low-Complexity Soft-Decision Feedback Turbo Equalization For Mimo Systems With Multilevel Modulations, Amirhossein Rafati, Huang Lou, Chengshan Xiao Sep 2011

Low-Complexity Soft-Decision Feedback Turbo Equalization For Mimo Systems With Multilevel Modulations, Amirhossein Rafati, Huang Lou, Chengshan Xiao

Electrical and Computer Engineering Faculty Research & Creative Works

Many communication systems today encounter the problem of data transmission over a channel with InterSymbol interference (ISI). the purpose of this paper is to develop a low-complexity iterative soft-decision feedback equalization (SDFE) receiver for severe frequency-selective ISI channels in multiple-input-multiple-output (MIMO) communication systems. the proposed SDFE algorithm offers a novel approach to combat error propagation. in addition, its computational complexity only linearly grows with the number of equalizer coefficients, compared with the quadratic complexity of minimum mean square error (MMSE)-Based linear turbo equalizer with time-varying coefficients. the performance of the proposed detection scheme is verified through simulations using different signal …

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Coaxial Cable Bragg Grating, Tao Wei, Songping Wu, Jie Huang, Hai Xiao, Jun Fan Sep 2011

Coaxial Cable Bragg Grating, Tao Wei, Songping Wu, Jie Huang, Hai Xiao, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

This paper reports a coaxial cable Bragg grating (CCBG) fabricated by drilling holes into the cable at periodic distances along the axial direction. Resonances were observed at discrete frequencies in both transmission and reflection spectra. The analogy of the CCBG with a fiber Bragg grating is shown. The grating was tested for the potential application as a strain-sensing device.

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Cascaded Microwave Network Approach For Power And Signal Integrity Analysis Of Multilayer Electronic Packages, Zaw Zaw Oo, En Xiao Liu, Xing Chang Wei, Yaojiang Zhang, Er Ping Li Sep 2011

Cascaded Microwave Network Approach For Power And Signal Integrity Analysis Of Multilayer Electronic Packages, Zaw Zaw Oo, En Xiao Liu, Xing Chang Wei, Yaojiang Zhang, Er Ping Li

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, an efficient cascaded microwave network approach is presented for power and signal integrity analysis of multilayer printed-circuit boards (PCBs) and advanced electronic packages with multiple signal traces, multiple power-ground plates, multiple vias, and external loads such as decoupling capacitors. Each parallel-plate pair, which consists of two consecutive conductor plates functioning as either power or ground in the PCBs or packages, is modeled as one individual microwave network. Equivalent circuits are used in the microwave network to model the vias, and a parallel-plate impedance matrix is formulated to account for the wave interactions between the vias and the …

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Electron Transport Through Two Irreducibly-Coupled Aharonov-Bohm Rings With Applications To Nanostructure Quantum Computing Circuits, C. A. Cain, Cheng-Hsiao Wu Sep 2011

Electron Transport Through Two Irreducibly-Coupled Aharonov-Bohm Rings With Applications To Nanostructure Quantum Computing Circuits, C. A. Cain, Cheng-Hsiao Wu

Electrical and Computer Engineering Faculty Research & Creative Works

We investigated several classes of two coupled Aharonov-Bohm rings that share a finite center common path, where the phase of the electron wave function can be modulated by two distinct magnetic fluxes. The coupling is similar to two coupled atoms. The behavior of charge accumulation along the center common path or, equivalently, the bonding and anti-bonding of the two rings can be achieved as the two applied fluxes are varied. Thus, when three external terminals are connected to such coupled rings, the behavior of the electron transport is divided into several classes, depending on the number of atoms in each …

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Proportionate Affine Projection Sign Algorithms For Network Echo Cancellation, Zengli Yang, Yahong Rosa Zheng, Steven L. Grant Aug 2011

Proportionate Affine Projection Sign Algorithms For Network Echo Cancellation, Zengli Yang, Yahong Rosa Zheng, Steven L. Grant

Electrical and Computer Engineering Faculty Research & Creative Works

Two proportionate affine projection sign algorithms (APSAs) are proposed for network echo cancellation (NEC) applications where the impulse response is often real valued with sparse coefficients and long filter length. the proposed proportionate-type algorithms can achieve fast convergence and low steady-state misalignment by adopting a proportionate regularization matrix to the APSA. Benefiting from the characteristics of l1-norm optimization, affine projection, and proportionate matrix, the new algorithms are more robust to impulsive interferences and colored input than the proportionate least mean squares (PNLMS) algorithm and the robust proportionate affine projection algorithm (Robust PAPA). the new algorithms also achieve much faster convergence …

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Design Optimization Of Linear Precoders For Complex Vector Gaussian Channelswith Finite Alphabet Inputs, Chengshan Xiao, Yahong Rosa Zheng, Zhi Ding Aug 2011

Design Optimization Of Linear Precoders For Complex Vector Gaussian Channelswith Finite Alphabet Inputs, Chengshan Xiao, Yahong Rosa Zheng, Zhi Ding

Electrical and Computer Engineering Faculty Research & Creative Works

We study the design optimization of linear precoders that maximize the mutual information in complex-valued vector Gaussian channels under finite alphabet inputs. It is well known that mutual information of a vector channel with discrete constellation source is a highly nonlinear and nonconcave function of the linear precoder matrix G, thereby complicating the precoder design optimization. in this paper, we show that the mutual information is a concave function of W = GhHhHG, where H is the complex-valued channel matrix and superscript "h" represents conjugate transpose. We further propose an iterative algorithm for solving the globally optimal linear precoder G. …

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Proportionate Affine Projection Sign Algorithms For Sparse System Identification In Impulsive Interference, Zengli Yang, Yahong Rosa Zheng, Steven L. Grant Aug 2011

Proportionate Affine Projection Sign Algorithms For Sparse System Identification In Impulsive Interference, Zengli Yang, Yahong Rosa Zheng, Steven L. Grant

Electrical and Computer Engineering Faculty Research & Creative Works

Two proportionate affine projection sign algorithms (APSAs) are proposed for system identification applications, such as network echo cancellation (NEC), where the impulse response is often real valued with sparse coefficients and long filter length. the proposed proportionate-type algorithms can achieve fast convergence and low steady-state misalignment by adopting a proportionate regularization matrix to the APSA. Benefiting from the characteristic of l1-norm algorithms, affine projection, and proportionate matrix, the new algorithms are robust to impulsive interferences and colored input and achieve much faster convergence rate in sparse impulse responses than the original APSA, the normalized sign algorithm (NSA), and the proportionate …

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Comparison Of Tdnn And Rnn Performances For Neuro-Identification On Small To Medium-Sized Power Systems, Diogenes Molina, Jiaqi Liang, Ron Harley, Ganesh K. Venayagamoorthy Aug 2011

Comparison Of Tdnn And Rnn Performances For Neuro-Identification On Small To Medium-Sized Power Systems, Diogenes Molina, Jiaqi Liang, Ron Harley, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

For Artificial Neural Networks (ANN) to become more widely used in power systems and the future smart grids, ANN based algorithms must be capable of scaling up as they try to identify and control larger and larger parts of a power system. This paper goes through the process of scaling up an ANN based identifier as it is driven to identify increasingly larger portions of a power system. Distributed and centralized approaches for scaling up are taken and the pros and cons of each are presented. the New England/New York 68-bus power network is used as the test bed for …

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