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Full-Text Articles in Engineering
Channel Modeling For Vehicle-To-Vehicle Communications, David W. Matolak
Channel Modeling For Vehicle-To-Vehicle Communications, David W. Matolak
Faculty Publications
Physical layer channel modeling is critical for design and performance evaluation at multiple layers of the communications protocol stack. In this article we describe and provide results for modeling vehicle-to-vehicle (V2V) wireless channels. V2V settings produce some unique conditions, and due to these conditions, V2V channels often exhibit greater dynamics than many conventional channels and, in addition, can also exhibit more severe fading. Thus, new channel models are needed to characterize this setting in order to evaluate contending transmission schemes and aid in V2V communication system design. A brief review of key statistical channel parameters is provided. Then both analytical …
Spectrally Shaped Generalized Mc-Ds-Cdma With Dual Band Combining For Increased Diversity, Wenhui Xiong, David W. Matolak
Spectrally Shaped Generalized Mc-Ds-Cdma With Dual Band Combining For Increased Diversity, Wenhui Xiong, David W. Matolak
Faculty Publications
A new multicarrier spread spectrum modulation scheme is proposed in this paper. This scheme uses sinusoidal chip waveforms to shape the spectrum of each subcarrier of a multicarrier direct sequence spread spectrum (DS-SS) signal. As a result, each subcarrier has two distinct spectral lobes, one a lower sideband (LSB) and the other an upper sideband (USB). By properly selecting the parameters of the sinusoidal chip waveforms, the two sideband signals can be made to undergo independent fading in a dispersive fading channel. These two independently-faded sideband signals, when combined at the receiver, provide diversity gain to the system. Our analysis …
Digital Oxide Deposition Of Sio2 Layers For Iii-Nitride Metal-Oxide-Semiconductor Heterostructure Field-Effect Transistors, V. Adivarahan, S. Rai, N. Tipirneni, A. Koudymov, J. Yang, Grigory Simin, M. Asif Khan
Digital Oxide Deposition Of Sio2 Layers For Iii-Nitride Metal-Oxide-Semiconductor Heterostructure Field-Effect Transistors, V. Adivarahan, S. Rai, N. Tipirneni, A. Koudymov, J. Yang, Grigory Simin, M. Asif Khan
Faculty Publications
We present a digital-oxide-deposition (DOD) technique to deposit high quality SiO2dielectric layers by plasma-enhanced chemical vapor deposition using alternate pulses of silicon and oxygen precursors. The DOD procedure allows for a precise thickness control and results in extremely smooth insulating SiO2 layers. An insulating gate AlGaN∕GaNheterostructurefield-effect transistor(HFET) with 8nm thick DOD SiO2dielectric layer had a threshold voltage of −6V (only 1V higher than that of regular HFET), very low threshold voltage dispersion, and output continuous wave rf power of 15W∕mm at 55V drain bias.
Detection For A Statistically-Known, Time-Varying Dispersive Channel, David W. Matolak, S. G. Wilson
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 …