Noise measurement

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

Event-triggered state estimation in vector linear processes

Abstract: This paper considers a distributed estimation problem in which a sensor sporadically transmits information to a remote-observer. An event-triggered approach is used to trigger the transmission of information from the sensor to the remote-observer. The event-trigger is chosen to minimize the mean square estimation error at the remote-observer subject to a constraint on how frequently the information can be transmitted. This problem was studied by O.C. Imer et al. [1] and M. Rabi et al. [2] where the observed process was a scalar linear system over a finite time interval. This paper extends those earlier results by relaxing the prior assumption that the initial condition is zero-mean with no measurement noise. It extends those earlier results to vector linear systems through a computationally efficient way of computing sub-optimal event-triggering thresholds.

Influence of the spatial coherence of the background noise on high resolution passive methods

Abstract: Research directed towards the improvement of underwater passive listening technique has led to powerful methods but which require the knowledge of the spatial coherences of the sources and of the background noise They are sensitive to the shape of the wavefront of the signals from the sources But they are also sensitive to the spatial coherence of the background noise : this is shown in this paper in particular for the method of the indentification of the components of the noisefield from the eigenvectors and eigenvalues of the spectral density matrix of the signals received on the array

Noise in mixers, oscillators, samplers, and logic an introduction to cyclostationary noise

Abstract: The proliferation of wireless and mobile products has dramatically increased the number and variety of low power, high performance electronic systems being designed. Noise is an important limiting factor in these systems. The noise generated is often cyclostationary. This type of noise cannot be predicted using SPICE, nor is it well handled by traditional test equipment such as spectrum analyzers or noise figure meters, but it is available from the new RF simulators. The origins and characteristics of cyclostationary noise are described in a way that allows designers to understand the impact of cyclostationarity on their circuits. In particular, cyclostationary noise in time-varying systems (mixers), sampling systems (switched filters and sample/holds), thresholding systems (logic circuitry), and autonomous systems (oscillators) is discussed.

Adaptive Noise Mitigation in Impulsive Environment: Application to Power-Line Communications

Abstract: In this paper, we address the general issue of asynchronous impulsive noise mitigation and its application over coded power-line communications (PLC). As is well known, PLC channels usually suffer from significant degradation due to impulsive interference generated by electrical appliances. The use of a level limiter is a simple and intuitive technique, widely used to mitigate the noxious effect of impulsive noise in these channels. However, the determination of the clipping threshold remains, most of the time, empirical, and the impulse statistics are usually assumed to be known. In a previous study, we proposed an original threshold determination based on signal detection theory, using the well-known false alarm and good detection tradeoff. Here, we further investigate the proposed optimization method in closed form. We compare two tradeoff criteria by means of a receiver operating curves analysis. We clearly show that the resulting decision fits well with encountered bit-error rate performances. We also evaluate the influence of impulsive noise statistics estimation on the performance of the proposed approach. To do so, we assess the robustness of the classical method of moments on Gaussian mixture estimation. It clearly appears that the estimation method is reliable for reasonable values of the impulse occurrence. As one of the main results of this paper, we make a proposal for impulse statistics estimation under ?severe? conditions (i.e., for very rare impulse events, based on impulse detection over corrupted OFDM symbols). Subsequently, we propose a general scheme of automatic impulse mitigation, according to the disturbance ratio of the environment. Finally, the performance of the approach is evaluated over the Home-Plug AV (HPAV) physical layer.