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This work is intended to provide a set of guidelines for the design of digital-to-analog converters enabling the reduction of threshold dispersion in multichannel readout circuits for radiation detectors. The design criteria are first established through a theoretical approach and then confirmed by means of a simulation tool based on Monte Carlo methods. This latter tool provides a fast and flexible...
This paper proposes a Constrained Least Square approach to the problem of Blind Source Separation (BSS) in a non-stationary mixing environment. Initially the demixing matrix is identified for the nominal system using the standard Kullback-Liebler(KL) divergence minimization technique. The KL algorithm is computationally expensive requiring longer CPU time and a large collection of samples. Therefore...
This paper concerns the identification of nonlinear systems using a variant of the Wiener G-Functionals. The system is modeled by a cascade of a single input multiple output (SIMO) linear dynamic system, followed by a multiple input single output (MISO) static nonlinear system. The dynamic system is described using orthonormal basis functions. The original ideas date back to the Wiener G-functionals...
In this paper, stochastic signaling is studied for power-constrained scalar valued binary communications systems in the presence of uncertainties in channel state information (CSI). First, it is shown that, for a given decision rule at the receiver, stochastic signaling based on the available CSI at the transmitter results in a randomization between at most two different signal levels for each symbol...
In this paper we suggest the improvement and generalization of the wideband ambiguity function for radar signals. Sounding waveforms and reflected radar signals have different probability density functions, and this fact is not taken into account in classical definition of an ordinary ambiguity function. The proposed generalization of the ambiguity function is based on the copula notion and does not...
This work deals with the analytical derivation of the statistical properties of the distortion factors defined in the Standard IEC 61000-4-7 regarding harmonics and interharmonics measurements and instrumentation for power supply systems and equipment connected thereto. The statistical characterization is provided in terms of probability density function, cumulative distribution function, and statistical...
Q-Ball imaging (QBI) is a successful and widely used high angular resolution diffusion imaging (HARDI) technique which can compute orientation distribution function (ODF). This technique only needs single shell HARDI data and does not require any assumption about the diffusion signal outside the sampling sphere. However the originally proposed ODF (the radial project of the probability density function...
The floating-point to fixed-point transformation process is error prone and time consuming as the distortion introduced by the limited data size is difficult to evaluate. In this paper a method to estimate the range of variables in LTI systems with respect to the corresponding overflow probability is presented. Furthermore, we will show that the quantization noise evaluation can be realized using...
In this paper, the problem of detecting and classifying different types of terrain in Synthetic Aperture Radar, SAR, images is considered. SAR data are the result of the backscattered energy from the illuminated area, so SAR images cannot be considered as optical ones and, as a consequence, automatic feature extraction represents a difficult task. Due to the amount of data that must be processed,...
We consider the problem of extracting a specific feature from a noisy signal generated by a multi-channels Remote Field Eddy Current Sensor. The sensor is installed on a mobile robot whose mission is the detection of anomalous regions in metal pipelines. Given the presence of noise that characterizes the data series, anomaly signals could be masked by noise and therefore difficult to identify in some...
In this paper we propose a robust energy detector for spectrum sensing in cognitive radio systems. The detector is derived by modelling the noise process as consisting of two components, Gaussian noise and impulsive noise. The impulsive noise is modelled using a uniform distribution that appears with a certain probability. A convenient approximation using the max operator is then applied to the resulting...
The ferromagnetic insulating (FMI) state of low hole doped manganites forms a disordered electronic system showing Efros-Shklovskii variable range hopping (ESVRH) type hoping at low temperature with evidence of a soft Coulomb gap of ΔCG. The temperature dependent noise identified a freezing temperature where the freezing process is kinetically governed with the time scale determined by an activation...
Theory and results demonstrate, statistically and by implication, structurally, that the zero crossings of a generalized shot noise process are equivalent to those of a modified random telegraph signal based on grouping of Poisson points. The zero crossings are not statistically consistent with a Poisson point process.
We study the distribution of first return times at a given level L in stationary correlated signals. Our approach makes use of the relation between the characteristic function of the first return probability density function (PDF) and the occupation probability of the state L. In this work we consider a discrete in time and space Ornstein-Uhlenbeck (OU) process with exponential decaying correlation...
Radiation spectra represent inherently quantization data in the form of stacked channels of equal width. The spectrum is an experimental measurement of the discrete probability density function (PDF) of the detector pulse heights. The quantization granularity of the spectra depends on the total number of channels covering the full range of pulse heights. In analog pulse processing the total number...
Seeded Localized Averaging (SLA) is a spectrum acquisition method that averages pulse-heights in dynamic windows. SLA sharpens peaks in the acquired spectra. This work investigates the transformation of the original probability density function (PDF) in the process of applying SLA procedure. We derive an analytical expression for the resulting probability density function after an application of SLA...
The false alarm probability of a novel signal detection approach based on a two-channel interferometer is derived. The normalized detection threshold is computed using the golden section search algorithm.
The problem of dynamical tomography consists in reconstructing a temporal sequence of images from their noisy projections. For this purpose, a recursive algorithm is usually used, like for instance the Kalman Filter (KF), due to the dynamical structure of the problem. However, since it needs the inverse of innovation matrix, KF may suffer from a huge computational cost in cases of images with very...
High precision mixed-signal design strongly depends on trimming techniques to overcome manufacturing induced variability, of which the digital trimming is the most popular approach. The central element of a digitally driven trim circuit is the trim DAC. Whilst it needs to be simple and cheap its electrical performance in the digital to analogue conversion process will affect the trim result. In this...
The channel capacity and its asymptotic performance of a superposed M-PAM modulation are given. It is shown that the superposed high-order modulation is more effective, with fewer bit loads, to approach Shannon limit.
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