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The aim of this paper is to present a 3D positioning system based on phase measurements of the signals backscattered by the UHF RFID tags of a uniform circular array (UCA). Apart from the location estimations, the system is also able to provide the 2D attitude (azimuth and elevation) of the UCA. This complementary information can be very useful in some applications such as in loading operations at...
Spatial angular compounding (SAC) with plane wave has been proposed to improve the performance of motion and strain estimation at high frame rate. A previous study shows that the accuracy of 2D estimation depends on the number of steering angles, maximum steering angle, and accuracy of axial estimation at different angles (He et al, Ultrasonics 2017). We have demonstrated (Pan et al, TUFFC 2015) that...
Minimally invasive procedures such as microwave ablation (MWA) are growing in popularity as a substitute for surgical resection of hepatocellular carcinomas. Ultrasound electrode displacement elastography (EDE) has demonstrated the potential to provide a feasible non-invasive and non-ionizing approach for monitoring the region of thermal necrosis.
Affine-model-based optical flow method (OF) is a commonly used method for direct estimation of strain. Typically, two image frames are used to estimate the axial strain in OF (OF2). When the compression is relatively large (i.e., 3–5%), the performance of OF2 is deteriorated because of signal decorrelation. However, larger compression may lead to some new characteristics or increase the signal-to-noise...
Estimation is a critical component of synchronization in wireless and signal processing systems. There is a rich body of work on estimator derivation, optimization, and statistical characterization from analytic system models which are used pervasively today. We explore an alternative approach to building estimators which relies principally on approximate regression using large datasets and large...
In this paper, the BER performance of a soft distance successive cancellation decoder for Polar codes is analyzed in the presence of impulsive noise, modelled using both the Middleton's Class A model and the symmetric alpha-stable model, for impulsive noise channels. This algorithm avoids estimation of the signal-to-noise ratio of the channel, and simplifies the initialization step of the classic...
An accurate detection of unused part of the spectrum is a key requirement in cognitive radio system. In this context, it is necessary to set an appropriate threshold between signal and noise. As noise power is instantaneous in nature, a periodic estimation of noise power is required. In this paper, we have proposed a combination methodology, that uses Rank order filtering in tandem with a gradient...
This paper analyzes the effect of bubble noise and Doppler shift in an underwater acoustic communication in addition to the influences by ambient noise and severe multipath propagation. Here Bubbles are assumed to be formed due to breaking of waves under strong winds. The bubble layer thus formed alters the speed of the sound in the field. The changed speed of the sound in the field, results in transmission...
It is known that there exist two kinds of methods for direction-of-arrival (DOA) estimation in the literature: the subspace-based method and the sparsity-based method. However, pervious works reveal that the former method cannot address the case in which the number of signals is larger than that of sensors, whereas the latter one always suffers from the influence of basis mismatch. In this paper,...
Blind separation of mixtures has been achieved by approximate joint diagonalization (AJD) approaches. This paper presents an approach for overdetermined blind source separation (BSS) using AJD. The approach is based on an alternative minimization of the indirect and direct least-squares criteria to the diagonal matrices in the first phase and to the mixing matrix in the second phase, respectively...
In this paper, we address the estimation of power spectral density (PSD) matrix. The accurate estimation of PSD matrix plays an important role in many speech enhancement methods. In traditional PSD estimation methods, only the information of previous frames is employed through a forgetting factor. In the current research, we consider the correlation of inter-band components and incorporate their information...
Hearable is a recently emerging term that describes a wireless earpiece that enhances the user's listening experience in various acoustic environment. Another important feature of hearable devices is their capability to improve speech communication in difficult social settings, which usually consist of a mixture of different non-stationary noise. In this paper, we present techniques to suppress a...
In this paper, the regularization method and the Fourier domain deconvolution method with filter applied are used respectively for the operations of differentiation and deconvolution in the network identification by deconvolution (NID) process. The signal-to-noise ratio of the time-constant function is estimated as an evaluation of the result errors. The choosing criterion and influences of the parameters...
Given a collection of M experimentally measured subspaces, and a model-based subspace, this paper addresses the problem of finding a subspace that approximates the collection, under the constraint that it intersects the model-based subspace in a predetermined number of dimensions. This constrained subspace estimation (CSE) problem arises in applications such as beamforming, where the model-based subspace...
This paper proposes a new TDOA estimation based on phase-voting cross correlation and circular standard deviation. Based on phase delay and kernel function, the proposed method generates a probability density function (PDF) of TDOA for each frequency bin. TDOA estimate is determined by voting the PDFs generated for all frequency bins. Peak positions of the bin-wise PDFs for the target signal are concentrated...
In this paper a new direct nonparametric estimation of the period and the shape of a periodic component in short duration signals is proposed and evaluated. Classical Fourier Transform (FT) methods lack precision and resolution when the duration of the signal is very short and the signal is noisy. The proposed method is based on the direct description of the problem as a linear inverse problem and...
The paper is focused on finding appropriate and systematic procedures of denoising highly distorted small currents with significant “signal to noise” ratios and on evaluating the denoising effects over the power quality (PQ) indices. Real currents were acquired from 2 consumers placed in a small industrial hall with highly variable power consumptions. Denoising procedures relying on wavelet based...
Signal processing on graphs becomes popular nowadays due to its great potential in processing the large amount of high dimensional data which exhibit irregular structures. As a signal propagates on a graph, the signal at a later time slot can be thought of as the graph-filtered version of the previous one. Therefore, estimation of the graph filter is important and serves as the building block for...
The conventional algorithm of channel estimation based on IEEE802.11ac is Least Square (LS) algorithm, which uses the Very High Throughput-Long Training Field (VHTLTF) of frame header as training sequence. While the conventional algorithm does not take into account the effects of noise and the varying characteristics of channel in time domain. In order to describe the slow change of channel in time...
As a first step to Antarctic Blue Whale monitoring, a new method based on a passive application of the Stochastic Matched Filter (SMF) is developed. To perform Z-call detection in noisy environment, improvements on the classical SMF requirements are proposed. The signal's reference is adjusted, the background noise estimation is reevaluated to avoid operator's selection, and the time-dependent Signal...
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