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Full-Text Articles in Engineering
An Ultra Wide Band Simulator Using Matlab/Simulink, Peter Vial, Beata J. Wysocki, Tadeusz A. Wysocki
An Ultra Wide Band Simulator Using Matlab/Simulink, Peter Vial, Beata J. Wysocki, Tadeusz A. Wysocki
Department of Electrical and Computer Engineering: Faculty Publications (to 2015)
Ultra Wide Band (UWB) is a promising technology for sensor networks, broadband wireless data access and location finding applications. This study outlines the development and validation of a single transmitter and receiver system across the multipath channel proposed by Saleh-Valenzuela. We have designed and tested a UWB simulator using MATLAB’s Simulink in combination with the Real Time Workshop(RTW) Tool box for Simulink using the Fixed Step Discrete Solvers of RTW which is required to produce executable simulations on multiple computers (both Linux and Microsoft based devices). This paper outlines the basic design and modules chosen for the simulation and compares …
Using Asterisms To Decode Multi-User Mimo Systems, Phillip Conder, Tadeusz A. Wysocki
Using Asterisms To Decode Multi-User Mimo Systems, Phillip Conder, Tadeusz A. Wysocki
Department of Electrical and Computer Engineering: Faculty Publications (to 2015)
The area of Multiple Input Multiple Output (MIMO) communications systems has received enormous attention recently as they can provide a roughly linear increase in data rate by using multiple transmit and receive antennas. MIMO combined with an Turbo coding has been shown as a promising way to achieve near capacity for wireless channels. This paper proposes applying an Asterism based decoder to produce an additional multi user access scheme on top of the primary access method for Ad Hoc networks. After reviewing Sphere and Asterism decoding for MIMO systems with a larger number of transmit than receive antennas, this paper …
Background Radio Frequency Interference Measurements For Wireless Devices In The Electricity Supply Industry, Duane Robinson, Tadeusz A. Wysocki, V. Smith, K. Popovski
Background Radio Frequency Interference Measurements For Wireless Devices In The Electricity Supply Industry, Duane Robinson, Tadeusz A. Wysocki, V. Smith, K. Popovski
Department of Electrical and Computer Engineering: Faculty Publications (to 2015)
Incorporation of radio controller units into heavy equipment used in the electricity industry provides numerous advantages including: improved electrical isolation between plant and operator, ability to incorporate an additional remote operator, and reductions in vehicle wiring and hydraulic hoses for equipment control. However, secure operation of vehicles and plant incorporating radio control rely on establishing suitable levels of immunity to possible radio frequency interference. Interference levels in close proximity to high voltage power lines are of special concern to the electricity industry. This paper reports on a preliminary investigation into quantifying the levels of background radio interference at such locations …
Applicationofspectroscopic Ellipsometry To In-Stu. Real-Time Fabrication Of Multiple Layer Alternating High/Low Refractive Index Filters, Blaine D. Johs, Jeffery S. Hale, John A. Woollam, Craig M. Herzinger
Applicationofspectroscopic Ellipsometry To In-Stu. Real-Time Fabrication Of Multiple Layer Alternating High/Low Refractive Index Filters, Blaine D. Johs, Jeffery S. Hale, John A. Woollam, Craig M. Herzinger
Department of Electrical and Computer Engineering: Faculty Publications
Disclosed is application of oblique angle of incidence, reflection and/or transmission mode spectroscopic ellipsometry PSI and/or DELTA, (including combinations thereof and/or mathematical equivalents), vs. wavelength data to monitor and/or control fabrication of multiple layer high/low refractive index band-pass, band-reject and varied attenuation vs. wavelength filters, either alone or in combination with transmissive non-ellipsometric electromagnetic beam turning point vs. layer data obtained at an essentially normal angle of incidence.
System And Method Enabling Simultaneous Investigation Of Sample With Two Beams Of Electromagnetic Radiation, John A. Woollam, Galen L. Pfeiffer, Daniel W. Thompson, Blaine D. Johs, Craig M. Herzinger
System And Method Enabling Simultaneous Investigation Of Sample With Two Beams Of Electromagnetic Radiation, John A. Woollam, Galen L. Pfeiffer, Daniel W. Thompson, Blaine D. Johs, Craig M. Herzinger
Department of Electrical and Computer Engineering: Faculty Publications
Disclosed are system and method for a characterizing system consisting of a fluid sample on a two-sided stage, utilizing data obtained by applying, from both sides thereof, beams of electromagnetic radiation to a fluid coated surface in a containing cell volume. The beams can have the same or different wavelength content and/or polarization state and can be applied at the same or different magnitude angles-of-incidence, and a third typically unpolarized beam can be applied at a normal angle-of-incidence.
System And Method Enabling Simultaneous Investigation Of Sample With Two Beams Of Electromagnetic Radation, John A. Woollam, Galen L. Pfeiffer, Daniel W. Thompson, Blaine D. Johs, Craig M. Herzinger
System And Method Enabling Simultaneous Investigation Of Sample With Two Beams Of Electromagnetic Radation, John A. Woollam, Galen L. Pfeiffer, Daniel W. Thompson, Blaine D. Johs, Craig M. Herzinger
Department of Electrical and Computer Engineering: Faculty Publications
Disclosed are System and method for characterizing a System consisting of a fluid Sample on a two sided Stage, utilizing data obtained by applying, from both sides thereof, beams of electromagnetic radiation to a fluid coated Surface in a containing cell Volume. The beams can have the same or different wavelength content and/or polarization State, and can be applied at the same or different magnitude angles-of-incidence, and a third typically unpolarized beam can be applied at a normal angle-of-incidence.
Multi-Aoi-System For Easy Changing Angles Of Incidence In Ellipsometer, Polarimeter And Reflectometer Systems, Blaine D. Johs, Ping He, Martin M. Liphardt, Christopher A. Goeden, John A. Woollam, James D. Welch
Multi-Aoi-System For Easy Changing Angles Of Incidence In Ellipsometer, Polarimeter And Reflectometer Systems, Blaine D. Johs, Ping He, Martin M. Liphardt, Christopher A. Goeden, John A. Woollam, James D. Welch
Department of Electrical and Computer Engineering: Faculty Publications
Disclosed is a system for enabling easy sequential setting of different Angles-of-Incidence of a beam of electromagnetic radiation to a surface of a sample system, and to regression based methodology for evaluating and compensating the effects of the presence of electromagnetic beam intercepting angle-of-incidence changing systems, including where desired, parameterization of calibration parameters.
Editorial, Robert W. Stewart, Michael W. Hoffman, Stephan Weiss
Editorial, Robert W. Stewart, Michael W. Hoffman, Stephan Weiss
Department of Electrical and Computer Engineering: Faculty Publications
In the past years, digital signal processing (DSP) algorithms and architectures for baseband communication systems have fuelled the delivery of applications such as 3G mobile communications and wireless LAN to mass markets. This was made possible by a tremendous growth in the performance of computational devices such as digital signal processors and FPGAs, as well as an increase in sampling rates of conversion devices to potentially several 100 MHz. While the development of both computational devices and ADCs/DACs continues, thus permitting DSP to be applied at IF sampling rates and possibly beyond, the opportunities for further enhancing radio devices by …
Comparison Of Antenna Array Systems Using Ofdm For Software Radio Via The Sibic Model, Khoi D. Le, Michael W. Hoffman, Robert D. Palmer
Comparison Of Antenna Array Systems Using Ofdm For Software Radio Via The Sibic Model, Khoi D. Le, Michael W. Hoffman, Robert D. Palmer
Department of Electrical and Computer Engineering: Faculty Publications
This paper investigates the performance of two candidates for software radio WLAN, reconfigurable OFDM modulation and antenna diversity, in an indoor environment. The scenario considered is a 20m × 10m × 3m room with two base units and one mobile unit. The two base units use omnidirectional antennas to transmit and the mobile unit uses either a single antenna with equalizer, a fixed beamformer with equalizer, or an adaptive beamformer with equalizer to receive. The modulation constellation of the data is QPSK and 16-QAM. The response of the channel at the mobile unit is simulated using a three-dimensional indoor WLAN …
Preconditioning Of Primary Human Endothelial Cells With Inflammatory Mediators Alters The “Set Point” Of The Cell, Youichiro Wada, Hasan H. Otu, Shengqian Wu, Md. Ruhul Abid, Hitomi Okada, Towia Libermann, Tatsuhiko Kodama, Shu-Ching Shih, Takashi Minami, William C. Aird
Preconditioning Of Primary Human Endothelial Cells With Inflammatory Mediators Alters The “Set Point” Of The Cell, Youichiro Wada, Hasan H. Otu, Shengqian Wu, Md. Ruhul Abid, Hitomi Okada, Towia Libermann, Tatsuhiko Kodama, Shu-Ching Shih, Takashi Minami, William C. Aird
Department of Electrical and Computer Engineering: Faculty Publications
Endothelial cells are highly sensitive to changes in the extracellular milieu. Sepsis results in activation of inflammatory and coagulation pathways. We hypothesized that sepsis-associated mediators may alter the response capacity (so-called “set point”) of endothelial cells. Human umbilical vein endothelial cells (HUVEC) were preincubated in the presence or absence of tumor necrosis factor (TNF)-α, lipopolysaccharide (LPS), hypoxia, hyperthermia, and/or high glucose; treated with or without thrombin for 4 h; and then processed for RNase protection assays of selected activation markers. Priming with TNF-α and LPS significantly inhibited thrombin-mediated induction of vascular cell adhesion molecule-1, intercellular adhesion molecule-1, tissue factor, and …
A Novel Role For Gadd45Β As A Mediator Of Mmp-13 Gene Expression During Chondrocyte Terminal Differentiation, Kosei Ijiri, Luiz F. Zerbini, Haibing Peng, Ricardo G. Correa, Binfeng Lu, Nicole Walsh, Yani Zhao, Noboru Taniguchi, Xu-Ling Huang, Hasan H. Otu, Hong Wang, Jian Fei Wang, Setsuro Komiya, Patricia Ducy, Mahboob U. Rahman, Richard A. Flavell, Ellen M. Gravallese, Peter Oettgen, Towia A. Libermann, Mary B. Goldring
A Novel Role For Gadd45Β As A Mediator Of Mmp-13 Gene Expression During Chondrocyte Terminal Differentiation, Kosei Ijiri, Luiz F. Zerbini, Haibing Peng, Ricardo G. Correa, Binfeng Lu, Nicole Walsh, Yani Zhao, Noboru Taniguchi, Xu-Ling Huang, Hasan H. Otu, Hong Wang, Jian Fei Wang, Setsuro Komiya, Patricia Ducy, Mahboob U. Rahman, Richard A. Flavell, Ellen M. Gravallese, Peter Oettgen, Towia A. Libermann, Mary B. Goldring
Department of Electrical and Computer Engineering: Faculty Publications
The growth arrest and DNA damage-inducible 45β (GADD45β) gene product has been implicated in the stress response, cell cycle arrest, and apoptosis. Here we demonstrated the unexpected expression of GADD45β in the embryonic growth plate and uncovered its novel role as an essential mediator of matrix metalloproteinase-13 (MMP-13) expression during terminal chondrocyte differentiation. We identified GADD45β as a prominent early response gene induced by bone morphogenetic protein-2 (BMP-2) through a Smad1/Runx2-dependent pathway. Because this pathway is involved in skeletal development, we examined mouse embryonic growth plates, and we observed expression of Gadd45β mRNA coincident with Runx2 protein …
Range Imaging Observations Of Pmse Using The Eiscat Vhf Radar: Phase Calibration And First Results, J. R. Fernandez, R. D. Palmer, P. B. Chilson, I. Haggstrom, M. T. Rietveld
Range Imaging Observations Of Pmse Using The Eiscat Vhf Radar: Phase Calibration And First Results, J. R. Fernandez, R. D. Palmer, P. B. Chilson, I. Haggstrom, M. T. Rietveld
Department of Electrical and Computer Engineering: Faculty Publications
A novel phase calibration technique for use with the multiple-frequency Range IMaging (RIM) technique is introduced based on genetic algorithms. The method is used on data collected with the European Incoherent SCATter (EISCAT) VHF radar during a 2002 experiment with the goal of characterizing the vertical structure of Polar Mesosphere Summer Echoes (PMSE) over northern Norway. For typical Doppler measurements, the initial phases of the transmitter and receiver are not required to be the same. The EISCAT receiver systems exploit this fact, allowing a multistatic configuration. However, the RIM method relies on the small phase differences between closely spaced frequencies. …
Phased-Array Design For Biological Clutter Rejection: Simulation And Experimental Validation, B.L. Cheong, Michael Hoffman, R.D. Palmer, Stephen J. Frasier, F.J. Lopez-Dekker
Phased-Array Design For Biological Clutter Rejection: Simulation And Experimental Validation, B.L. Cheong, Michael Hoffman, R.D. Palmer, Stephen J. Frasier, F.J. Lopez-Dekker
Department of Electrical and Computer Engineering: Faculty Publications
This paper highlights recent results obtained with the Turbulent Eddy Profiler (TEP), which was devel- oped by the University of Massachusetts. This unique 915-MHz radar has up to 64 spatially separated receiving elements, each with an independent receiver. The calibrated raw data provided by this array could be processed using sophisticated imaging algorithms to resolve the horizontal structures within each range gate. After collecting all of the closely spaced horizontal slices, the TEP radar can produce three- dimensional images of echo power, radial velocity, and spectral width. From the radial velocity measure- ments, it is possible to estimate the three-dimensional …
Observations Of The Small-Scale Variability Of Precipitation Using An Imaging Radar, Robert D. Palmer, Boon Leng Cheong, Michael Hoffman, Stephen J. Frasier, F.J. Lopez-Dekker
Observations Of The Small-Scale Variability Of Precipitation Using An Imaging Radar, Robert D. Palmer, Boon Leng Cheong, Michael Hoffman, Stephen J. Frasier, F.J. Lopez-Dekker
Department of Electrical and Computer Engineering: Faculty Publications
For many years, spatial and temporal inhomogeneities in precipitation fields have been studied using scanning radars, cloud radars, and disdrometers, for example. Each measurement technique has its own advantages and disadvantages. Conventional profiling radars point vertically and collect data while the atmosphere advects across the field of view. Invoking Taylor’s frozen turbulence hypothesis, it is possible to construct time-history data, which are used to study the structure and dynamics of the atmosphere. In the present work, coherent radar imaging is used to estimate the true three-dimensional structure of the atmosphere within the field of view of the radar. The 915-MHz …
On The Performance Of Turbo Codes With Convolutional Interleavers, Sina Vafi, Tadeusz Wysocki
On The Performance Of Turbo Codes With Convolutional Interleavers, Sina Vafi, Tadeusz Wysocki
Department of Electrical and Computer Engineering: Faculty Publications (to 2015)
In this paper, some issues governing the block-wise performance of convolutional interleavers used in turbo codes are presented. Two different constructions of convolutional interleaver differing by the position of stuff bits in the interleaved data block are considered here. The performance assessment is based on the contribution of each weight to the overall code performance. For the given turbo code and each utilized interleaver, weight contribution is computed to finalize the code behavior in different signal to noise ratios. Simulations have been performed to verify the conducted analysis.
A Generalized Algorithm For The Generation Of Correlated Rayleigh Fading Envelopes In Radio Channels, Le Chung Tran, Tadeusz Wysocki, Jennifer Seberry, Alfred Mertins
A Generalized Algorithm For The Generation Of Correlated Rayleigh Fading Envelopes In Radio Channels, Le Chung Tran, Tadeusz Wysocki, Jennifer Seberry, Alfred Mertins
Department of Electrical and Computer Engineering: Faculty Publications (to 2015)
Although generation of correlated Rayleigh fading envelopes has been intensively considered in the literature, all conventional methods have their own shortcomings, which seriously impede their applicability. In this paper, a very general, straightforward algorithm for generation of an arbitrary number of Rayleigh envelopes with any desired, equal or unequal power, in wireless channels either with or without Doppler frequency shifts, is proposed. The proposed algorithm can be applied in case of spatial correlation, such as with antenna arrays in Multiple Input Multiple Output (MIMO) systems, or spectral correlation between the random processes like in Orthogonal Frequency Division Multiplexing (OFDM) systems. …
Combined Asterism And Sphere Decoder For Large Asymmetric Mimo Systems, Phillip Conder, Tadeusz Wysocki
Combined Asterism And Sphere Decoder For Large Asymmetric Mimo Systems, Phillip Conder, Tadeusz Wysocki
Department of Electrical and Computer Engineering: Faculty Publications (to 2015)
The area of Multiple Input Multiple Output (MIMO) communications systems has received enormous attention recently as they can provide a roughly linear increase in data rate by using Multiple Transmit and Receive antennas. The optimal detection strategy for a MIMO receiver is to perform a Maximum-Likelihood (ML) search over all possible transmitted symbol combinations which has an exponential complexity when the constellation size of number of transmit antennas increase. Sphere and Asterism decoders are schemes that achieved ML performance for MIMO systems, but both have shortcomings in computational complexity, Sphere decoding when nt > nr and Asterism when n …
Performance Of Convolutional Interleavers With Different Spacing Parameters In Turbo Codes, Sina Vafi, Tadeusz Wysocki
Performance Of Convolutional Interleavers With Different Spacing Parameters In Turbo Codes, Sina Vafi, Tadeusz Wysocki
Department of Electrical and Computer Engineering: Faculty Publications (to 2015)
This paper considers application of a convolutional interleaver and the issue of infuence of the space parameter in the turbo code performance. Similarly to previously considered convolutional interleavers, the new interleavers are designed as block interleavers and their performance in different code structures is compared with the interleaver having higher periods and space value of 1. In each comparison, the number of inserted stuff bits at the end of each data block is considered to be of similar order. Finally, suitable modification to the new interleavers is proposed improving performance for the codes with lower number of stuff bits.
Technical Chair’S Message, A. Beghdadi, Tadeusz Wysocki
Technical Chair’S Message, A. Beghdadi, Tadeusz Wysocki
Department of Electrical and Computer Engineering: Faculty Publications (to 2015)
We have organized an exciting technical program which includes tutorials, plenary sessions, and technical presentations. All technical submissions to the conference were based on full-length papers. Each paper has been assessed by at least two reviewers. This year marks the first time that a double-blind peer review process has been used in an ISSPA conference. Overall, the process was a great success with both authors and reviewers conforming to the double-blind review guidelines. We received 395 paper submissions, most of which were of very high quality. However, due to space limitations, only 228 articles were accepted for presentation at the …
Generalized Williamson And Wallis-Whiteman Constructions For Improved Square Order-8 Cois Stbc, Le Chung Tran, Tadeusz Wysocki, Jennifer Seberry, Alfred Mertins, Sarah A. Spence
Generalized Williamson And Wallis-Whiteman Constructions For Improved Square Order-8 Cois Stbc, Le Chung Tran, Tadeusz Wysocki, Jennifer Seberry, Alfred Mertins, Sarah A. Spence
Department of Electrical and Computer Engineering: Faculty Publications (to 2015)
Constructions of square, maximum rate Complex Orthogonal Space-Time Block Codes (CO STBCs) are well known, however codes constructed via the known methods include numerous zeros, which impede their practical implementation. By modifying the Williamson and Wallis-Whiteman arrays to apply to complex matrices, we propose two methods of construction of square, order-4n CO STBCs from square, order-n codes which satisfy certain properties. Applying the proposed methods, we construct square, maximum rate, order-8 CO STBCs with no zeros, such that the transmitted symbols equally disperse through transmit antennas. Those codes, referred to as the improved square …
Asterism Decoding For Turbo Coded Mimo Systems, Phillip Conder, Tadeusz Wysocki
Asterism Decoding For Turbo Coded Mimo Systems, Phillip Conder, Tadeusz Wysocki
Department of Electrical and Computer Engineering: Faculty Publications (to 2015)
The area of Multiple Input Multiple Output (MIMO) communications systems has received enormous attention recently as they can provide a roughly linear increase in data rate by using multiple transmit and receive antennas. MIMO combined with an Turbo coding has been shown as a promising way to achieve near capacity for wireless channels.
Where previously described decoders provide linear decoding where the number of receive antennas is at least equal to the number of transmit antennas, are computationally burdensome when nt > nr. Asterism decoding is a scheme that achieved ML performance for MIMO systems for any number …
A Generalized Algorithm For The Generation Of Correlated Rayleigh Fading Envelopes, Le Chung Tran, Tadeusz Wysocki, Jennifer Seberry, Alfred Mertins
A Generalized Algorithm For The Generation Of Correlated Rayleigh Fading Envelopes, Le Chung Tran, Tadeusz Wysocki, Jennifer Seberry, Alfred Mertins
Department of Electrical and Computer Engineering: Faculty Publications (to 2015)
Although generation of correlated Rayleigh fading envelopes has been intensively considered in the literature, all conventional methods have their own shortcomings, which seriously impede their applicability. In this paper, a very general, straightforward algorithm for generation of an arbitrary number of Rayleigh envelopes with any desired, equal or unequal power, in wireless channels either with or without Doppler frequency shifts, is proposed. The proposed algorithm can be applied in case of spatial correlation, such as with antenna arrays in Multiple Input Multiple Output (MIMO) systems, or spectral correlation between the random processes like in Orthogonal Frequency Division Multiplexing (OFDM) systems. …