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Noncoherent multi-user detection schemes in combination with subspace projection were shown to be an attractive approach in multi-user massive MIMO systems. Up to now, the subspace projection has been performed via a singular value decomposition (SVD) of the receive matrix and nulling the non-signal dimensions. In this paper, we employ an alternative approach to the subspace estimation step, namely...
In this paper, a novel phase noise estimation method (PNE) for multi-level modulations is proposed based on local optimization (LO PNE). The effectiveness of this method is demonstrated and discussed in a 200G bit/s coherent transmission system. It has been proved, the usage of throwing-point (TP) test rotation and convex programming in LO_PNE reduce the complexity of phase estimation for arbitrary...
The exponential growth of available data has increased the need for interactive exploratory analysis. Dataset can no longer be understood through manual crawling and simple statistics. In Geographical Information Systems (GIS), the dataset is often composed of events localized in space and time; and visualizing such a dataset involves building a map of where the events occurred.We focus in this paper...
The notion of complexity is widely-known and used. Various definitions of complexity exist: the Hausdorff dimension, fractal dimension, Kolmogorov complexity, Krohn-Rhodes complexity, Lyapunov exponents or the entropy, some of them with several definitions. All these measures were defined strictly for mathematical objects, but they may apply to real signals like texture images in particular. We are...
Using OMP algorithm for time-delay detecting and apply BEM based on comb-type pilot for channel estimation is the most commonly used method for sparse time-frequency doubly-selective channels, but the channel estimation performance will decrease sharply when the number of channel paths is large, and this method need to obtain the channel sparsity as prior information in advance. In this paper, a novel...
The paper considers periodogram maximization-based frequency estimation of a single complex sinusoid. We propose to improve the accuracy of recently proposed methods based on three discrete Fourier transform (DFT) samples around the DFT maximum. For that purpose, a three-point parabolic interpolation of the periodogram peak is used. The proposed method requires the calculation of only two additional...
The estimation of symbol timing offset (STO) is an important issue for orthogonal frequency division multiplexing (OFDM) systems. In the literature, a variety of STO estimation methods have been proposed. In this paper, we propose a new blind STO estimation for OFDM systems with constant modulus (CM) constellation. The proposed estimator can estimate STO with only one OFDM symbol. Besides, a low complexity...
In this paper, a fast algorithm is proposed to tackle the constrained total generalized variation (TGV) based image restoration problem. The proposed algorithm proceeds by splitting: the nonsmooth constrained TGV model is first decomposed into several subproblems easier to solve; then the linear gradient or proximity operators, including projections and shrinkages, of the subproblems are individually...
Different from representation learning models using deep learning to project original feature space into lower density ones, we propose a feature space learning (FSL) model based on a semi-supervised clustering framework. There are three main contributions in our approach: (1) Inspired by Zipf's law and word bursts, the feature space learning processes not only select trusted unlabeled samples and...
The theory of belief functions is an effective tool to deal with the multiple uncertain information. In recent years, many evidence combination rules have been proposed in this framework, such as the conjunctive rule, the cautious rule, the PCR (Proportional Conflict Redistribution) rules and so on. These rules can be adopted for different types of sources. However, most of these rules are not applicable...
Online inquiry communities such as Question-Answer Communities (QAC) have captured interest of online users since they can share and search for any information from any place in the world. The number of questions and answers submitted to a popular community can increase rapidly, and that can make it difficult for users who look for the “right” questions to answer. That is, from the view of knowledgeable...
Global motion estimation (GME) algorithms are typically employed on aerial videos captured by on-board UAV cameras to compensate for the artificial motion induced in these video frames due to camera motion. However, existing methods for GME have high computational complexity and are therefore not suitable for on-board processing in UAVs with limited computing capabilities. In this paper, we propose...
Estimation of functions of d variables is considered using ridge combinations of the form Σmk=1 c1, kφ(Σdj=1c0, j, kxj-bk) where the activation function φ is a function with bounded value and derivative. These include single-hidden layer neural networks, polynomials, and sinusoidal models. From a sample of size n of possibly noisy values at random sites X ∊ B = [−1, 1]d, the minimax mean square error...
This paper studies the complexity of estimating Rényi divergences of discrete distributions: p observed from samples and the baseline distribution q known a priori. Extending the results of Acharya et al. (SODA'15) on estimating Rényi entropy, we present improved estimation techniques together with upper and lower bounds on the sample complexity. We show that, contrarily to estimating Rényi entropy...
Hypothesis testing of covariance matrices is an important problem in multivariate analysis. Given n data samples and a covariance matrix Σο, the goal is to determine whether or not the data is consistent with this matrix. In this paper we introduce a framework that we call sketched covariance testing, where the data is provided after being compressed by multiplying by a “sketching” matrix A chosen...
This paper investigates a signal area (SA) estimation method for spectrum measurements. The spectrum measurements is for estimating statistical information of spectrum usage and required latency is not very critical compared to spectrum sensing. SA denotes the area (in time/frequency domain) occupied by the primary user's signal. The traditional approach, which utilizes Fourier transform (FT) and...
This paper proposes a novel estimator for active and reactive power control of single-phase power electronic applications. The proposed estimator includes: 1) an instantaneous grid power regression model; 2) a fast upper-triangular and diagonal recursive least square (FUDRLS) algorithm for parameter identification of the regression model; and 3) a new self-tuning variable forgetting factor included...
In this paper, a novel pilot-aided algorithm is proposed for the detection of integer frequency offset (IFO) in orthogonal frequency division multiplexing (OFDM) systems. By transforming the IFO into two new integer parameters, the proposed method can largely reduce the number of trial values for the true IFO. The two new integer parameters are detected using two different pilot sequences, a periodic...
Three methods for extracting the behavioral modeling coefficients of the memory polynomial model are compared herein. The first one is the ordinary least square regression, which is widely used for adjusting model parameters; the second is the order recursive least squares, which is suitable for exploring the optimal nonlinearity order and memory depth by comparing subsequent errors while increasing...
The aim of this article is to explore the reliability of electronic units, which are parts of complex electronic systems. A failure rates estimation of such units is performed, following a technique based on data for their technical characteristics, such as circuit diagrams, operational regimes and component specifications. A comparison is made of the values obtained with analogous data, valid for...
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