Title of dissertation: LOW PHASE NOISE CMOS PLL FREQUENCY SYNTHESIZER DESIGN AND ANALYSIS Xinhua He, Doctor of Philosophy, 2007 Dissertation directed by: Professor Robert Newcomb Department of Electrical and Computer Engineering The phase-locked loop (PLL) frequency synthesizer is a critical device of wireless transceivers. It works as a local oscillator (LO) for frequency translation and chann...

background: sound is one of the most important factors threatening workers’ health. the most efficient and practical method for controlling noise pollution is the use of sound-absorbing materials. impedance tube with two microphones is used to determine the sound absorption coefficients and should be tested periodically for accuracy and efficiency. the purpose of present study was assessing the...

An important aspect of noise robustness of automatic speech recognisers (ASR) is the proper handling of non-speech acoustic events. The present paper describes further improvements of an already existing reference recogniser towards achieving such kind of robustness. The reference recogniser applied is the COST 249 SpeechDat reference recogniser, which is a fully automatic, language-independent...

This research presents a new method of distinguishing between noisy, blurred and otherwise uncorrupted images via the Fourier transform. The spectrum of an image corrupted by noise is markedly different from one that is marred by blurring, or one that is not damaged at all. In particular, there are more high frequency terms in the spectrum of a noisy image than in that of a blurred image, and, ...

The LMS (Least-Mean-Square) algorithm, which can obtain the complex transfer function in real-time, allows the changes of noise characteristics and the environment of system, thereby maintaining the convergence performance. Therefore, many algorithms based on the LMS algorithm have been modified to solve for some practical considerations, and the FXLMS (Filtered-X LMS) algorithm has been widely...

Noise is one fundamental quality attribute in digital cameras. Traditionally, noise has been measured from solid patches of artificial test targets. In image quality research, it has been difficult to find connections between a test target and subjective test data. In addition, image quality algorithms computed from natural images are not well correlated. In this paper, we propose a novel appro...

The 2500WH MEG system by 4D Neuroimaging has magnetometer detectors that rely on real-time noise reduction in addition to shielding of a magnetically shielded room. Theoretically, the set of reference magnetometers and gradiometers, distant from the recording array, are sufficient to remove environmental noise through first order spatial variation within the shielded room. However, in magnetica...

in which 4o is the self power spectrum of the noise voltage, To is the self power 0 0 spectrum of the noise current, A is the imaginary part of the cross power spectrum 0 of the noise voltage and current, and H is the real part of the cross power spectrum; O0 the subscript o indicates that all noise power spectra are taken at a reference plane beyond the potential minimum in the electron gun. T...