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Full-Text Articles in Physical Sciences and Mathematics
Integration Of Dft And Cosine-Modulated Filter Banks With Blind Separation Of Convolutively Mixed Non-Stationary Sources, I. Russell, Jiangtao Xi, Alfred Mertins, Joe F. Chicharo
Integration Of Dft And Cosine-Modulated Filter Banks With Blind Separation Of Convolutively Mixed Non-Stationary Sources, I. Russell, Jiangtao Xi, Alfred Mertins, Joe F. Chicharo
Faculty of Informatics - Papers (Archive)
In this paper, oversampled M channel FIR filter banks using both DFT modulation and cosine modulation designs are used in conjunction with a time domain blind source separation (BSS) algorithm I. Russell et al., (2003). This BSS algorithm has been shown to blindly separate the fullband versions of non-stationary convolutively mixed sources in the time domain. However further savings on convergence and computational complexity can be made by using subband decomposition on the mixed signals before implementation of the time domain BSS algorithm in each subband. An extended lapped transform (ELT) prototype is modulated using a cosine-modulated (CM) FIR filter …
Multi-Modulation Schemes To Increase The Rate Space-Time Block Codes In Rayleigh Fading Channels, Le Chung Tran, Tadeusz A. Wysocki, Alfred Mertins
Multi-Modulation Schemes To Increase The Rate Space-Time Block Codes In Rayleigh Fading Channels, Le Chung Tran, Tadeusz A. Wysocki, Alfred Mertins
Faculty of Informatics - Papers (Archive)
The paper examines multimodulation schemes (MMSs) to increase the rate of our two new complex orthogonal designs (CODs) proposed for eight transmit antennas, namely C/sub 1/ and C/sub 2/, corresponding to the Amicable Orthogonal Designs (AODs) (8;1,1,2,2;1,1,2,2) and (8;1,1,1,4;1,1,1,4), respectively. In addition, the optimal intersymbol power allocation in the proposed codes in single modulation as well as in MMSs in flat Rayleigh fading channels is considered. It turns out that, in some modulation schemes, equal power transmission per each symbol time slot is not only optimal from the technical point of view, but also optimal in terms of achieving the …
On Some Antenna Selection Techniques For Wireless Channels Utilizing Differential Space-Time Modulation, Le Chung Tran, Tadeusz A. Wysocki
On Some Antenna Selection Techniques For Wireless Channels Utilizing Differential Space-Time Modulation, Le Chung Tran, Tadeusz A. Wysocki
Faculty of Informatics - Papers (Archive)
The paper deals with antenna selection techniques for wireless channels utilizing differential space-time modulation. We propose here the restricted N-out-of-M antenna selection technique providing relatively good bit error performance, while using only one feedback bit for transmit diversity purpose. In addition, we also present an improved N-out-of-(N+1) antenna selection technique, which shortens the time required for processing feedback information. These techniques remarkably improve performance of wireless channels using differential detection.
Quantitative Force Measurements In Liquid Using Frequency Modulation Atomic Force Microscopy, Suzi P. Jarvis, S. Akita, Takayuki Uchihashi, John E. Sader, Y. Nakayama, Michael J. Higgins, S Yasuda
Quantitative Force Measurements In Liquid Using Frequency Modulation Atomic Force Microscopy, Suzi P. Jarvis, S. Akita, Takayuki Uchihashi, John E. Sader, Y. Nakayama, Michael J. Higgins, S Yasuda
Faculty of Science - Papers (Archive)
The measurement of short-range forces with the atomic force microscope (AFM) typically requires implementation of dynamic techniques to maintain sensitivity and stability. While frequency modulation atomic force microscopy (FM-AFM) is used widely for high-resolution imaging and quantitative force measurements in vacuum, quantitative force measurements using FM-AFM in liquids have proven elusive. Here we demonstrate that the formalism derived for operation in vacuum can also be used in liquids, provided certain modifications are implemented. To facilitate comparison with previous measurements taken using surface forces apparatus, we choose a model system (octamethylcyclotetrasiloxane) that is known to exhibit short-ranged structural ordering when confined …