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Electrical and Computer Engineering

Faculty Publications

1996

Articles 1 - 7 of 7

Full-Text Articles in Engineering

Three-Dimensional Display Utilizing A Diffractive Optical Element And An Active Matrix Liquid Crystal Display, Gregory P. Nordin, M. W. Jones, S. T. Kowel, J. H. Kulick, R. G. Lindquist Dec 1996

Three-Dimensional Display Utilizing A Diffractive Optical Element And An Active Matrix Liquid Crystal Display, Gregory P. Nordin, M. W. Jones, S. T. Kowel, J. H. Kulick, R. G. Lindquist

Faculty Publications

We describe the design, construction, and performance of the first real-time autostereoscopic three-dimensional (3-D) display based on the partial pixel 3-D display architecture. The primary optical components of the 3-D display are an active-matrix liquid crystal display and a diffractive optical element (DOE). The display operates at video frame rates and is driven with a conventional VGA signal. Three-dimensional animations with horizontal motion parallax are readily viewable as sets of stereo images. Formation of the virtual viewing slits by diffraction from the partial pixel apertures is experimentally verified. The measured contrast and perceived brightness of the display are excellent, but …

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Detection For A Statistically-Known, Time-Varying Dispersive Channel, David W. Matolak, S. G. Wilson Dec 1996

Detection For A Statistically-Known, Time-Varying Dispersive Channel, David W. Matolak, S. G. Wilson

Faculty Publications

Detection for the statistically known channel (SKC) is aimed at obtaining good performance in situations where our statistical knowledge of a time-varying channel is good, and where other equalization/detection schemes are either too complex to implement, or their performance is limited due to the rapidity of channel fading, or where we are simply unable to perform channel estimation. By using a statistical characterization of the channel, we develop a new detector that performs maximum-likelihood sequence estimation (MLSE) (given the channel model) on blocks of N symbols. Both symbol-spaced and fractionally spaced samples are used, to obtain two different detectors, that …

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Low-Frequency Noise In 4h-Silicon Carbide Junction Field Effect Transistors, J. W. Palmour, M. E. Levinshtein, S. L. Rumyantsev, Grigory Simin May 1996

Low-Frequency Noise In 4h-Silicon Carbide Junction Field Effect Transistors, J. W. Palmour, M. E. Levinshtein, S. L. Rumyantsev, Grigory Simin

Faculty Publications

Low frequency noise in 4H‐silicon carbide junction field effect transistors (JFETs) has been investigated. JFETs with a buried p + n junction gate were manufactured by CREE Research Inc. Very low noise level has been observed in the JFETs. At 300 K the value of Hooge constant α is as small as α∼10−5 and the α value can be decreased by an appropriate annealing to α∼2×10−6. It has been shown that even these extremely low noise values are determined not by the volume noise sources but by the noise at the SiC–SiO2 interface.

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Dependence Of The Normalized Radar Cross Section Of Water Waves On Bragg Wavelength-Wind Speed Sensitivity, David G. Long, R. Scott Collyer, David V. Arnold May 1996

Dependence Of The Normalized Radar Cross Section Of Water Waves On Bragg Wavelength-Wind Speed Sensitivity, David G. Long, R. Scott Collyer, David V. Arnold

Faculty Publications

Measurements of the normalized radar cross section (O) made by the YSCAT ultrawideband scatterometer during an extended deployment on the Canada Centre for Inland Waters (CCIW) Research Tower located at Lake Ontario are analyzed and compared with anemometer wind measurements to study the sensitivity of O to the wind speed as a function of the Bragg wavelength. This paper concentrates on upwind and downwind azimuth angles in the wind speed range of 4.5-12 m/s. While YSCAT collected measurements of O at a variety of frequencies and incidence angles, this paper focuses on frequencies of 2.0, 3.05, 5.30, 10.02, and 14.0 …

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Calibration Of Spaceborne Scatterometers Using Tropical Rain Forests, David G. Long, Gary B. Skouson Mar 1996

Calibration Of Spaceborne Scatterometers Using Tropical Rain Forests, David G. Long, Gary B. Skouson

Faculty Publications

Wind scatterometers are radar systems designed specifically to measure the normalized radar backscatter coefficient (O) of the ocean's surface in order to determine the near-surface wind vector. Postlaunch calibration of a wind scatterometer can be performed with an extended-area natural target such as the Amazon tropical rain forest. Rain forests exhibit a remarkably high degree of homogeneity in their radar response over a very large area though some spatial and temporal variability exist. The authors present a simple technique for calibrating scatterometer data using tropical rain forests, Using a polynomial model for the rolloff of O with incidence angle, the …

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Variable-Complexity Trellis Decoding Of Binary Convolutional Codes, David W. Matolak, S. G. Wilson Feb 1996

Variable-Complexity Trellis Decoding Of Binary Convolutional Codes, David W. Matolak, S. G. Wilson

Faculty Publications

Considers trellis decoding of convolutional codes with selectable effort, as measured by decoder complexity. Decoding is described for single parent codes with a variety of complexities, with performance "near" that of the optimal fixed receiver complexity coding system. Effective free distance is examined. Criteria are proposed for ranking parent codes, and some codes found to be best according to the criteria are tabulated, Several codes with effective free distance better than the best code of comparable complexity were found. Asymptotic (high SNR) performance analysis and error propagation are discussed. Simulation results are also provided.

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Coded Modulation For Satellite Broadcasting, Robert H. Morelos-Zaragoza, Oscar Y. Takeshita, Hideki Imai, Marc P. C. Fossorier, Shu Lin Jan 1996

Coded Modulation For Satellite Broadcasting, Robert H. Morelos-Zaragoza, Oscar Y. Takeshita, Hideki Imai, Marc P. C. Fossorier, Shu Lin

Faculty Publications

In this paper, three-level block coded 8-PSK modulations, suitable for satellite broadcasting of digital TV signals, are presented. A design principle to achieve unequal error protection is introduced. The coding scheme is designed in such a way that the information bits carrying the basic definition TV signal have a lower error rate than the high definition information bits. The large error coefficients, formally associated with standard mapping by set partitioning, are reduced by considering a nonstandard partition of an 8-PSK signal set. The bits-to-signal mapping induced by this partition allows the use of suboptimal low-complexity soft-decision decoding of binary block …

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