Noise measurement

About: Noise measurement is a research topic. Over the lifetime, 19776 publications have been published within this topic receiving 308180 citations.

Electronic Noise and Interfering Signals: Principles and Applications

Abstract: Intrinsic Noise.- Fundamental Concepts.- Physical Noise Sources.- Noise Parameters.- Noise Analysis of Linear Circuits.- Frequency Domain Noise Analysis of Linear Multiports.- Noise Models of Electronic Devices.- Interfering Signals.- External Noise.- Interference Reduction Methods.- Methods of Reducing Emission of Interfering Signals.- Interconnection Modeling and Crosstalk.- Methods of Increasing Immunity to Interfering Signals.- Case Studies.- Low-Noise Circuit Design.- Noise Performance Measurement.- Noise in Sensing Circuits.- Noise in Communication Systems.- Computer-Aided Noise Analysis.- Protection Against Interfering Signals.

Noise cancelling of MRS signals combining model-based removal of powerline harmonics and multichannel Wiener filtering

Abstract: SUMMARY The fidelity of magnetic resonance sounding signals is often severely degraded by noise, primarily electrical interference from powerline harmonics and short electromagnetic discharges. In many circumstances, the noise originates from multiple sources. We show that noise cancelling can be improved if the multiple origins of noise are taken into account. In particular, a method is developed where powerline harmonics are efficiently removed through a modelbased approach. Subsequently, standard multichannel Wiener filtering can be used to provide a further noise reduction. The performance of the method depends on the distribution of noise on the particular site of measurement. Simulations on synthetic signals embedded in real noise recordings show that the combined approach can improve the signal-to-noise ratio with an accompanying improvement in retrieval of model parameters.

Voice activity detection driven noise remediator

Abstract: A method and apparatus for improving sound quality in a digital cellular radio system receiver. A voice activity detector uses an energy estimate to detect the presence of speech in a received speech signal in a noise environment. When no speech is present the system attenuates the signal and inserts low pass filtered white noise. In addition, a set of high pass filters are used to filter the signal based upon the background noise level. This high pass filtering is applied to the signal regardless of whether speech is present. Thus, a combination of signal attenuation with insertion of low pass filtered white noise during periods of non-speech, along with high pass filtering of the signal, improves sound quality when decoding speech which has been encoded in a noisy environment.

Impulse generation with appropriate amplitude, length, inter-arrival, and spectral characteristics

Abstract: This paper proposes a suitable method for simulating impulses with appropriate amplitude, spectral, and inter-arrival characteristics. The statistics used to develop the parameters of this model are based on statistics derived from observations of impulse noise on the telephone networks of British Telecom (BT) and Deutsche Telekom (DT). This paper initially reviews the former DT approach to impulse noise generation for testing digital subscriber line systems, so called xDSL systems. Some problems are highlighted and an alternative technique is suggested that is capable of generating impulses with both appropriate amplitude an spectral characteristics.