Results 1 to 10 of about 401,989 (143)

Channel Covariance Matrix Estimation via Dimension Reduction for Hybrid MIMO MmWave Communication Systems. [PDF]

open access: yesSensors (Basel), 2019
Hybrid massive MIMO structures with lower hardware complexity and power consumption have been considered as a potential candidate for millimeter wave (mmWave) communications. Channel covariance information can be used for designing transmitter precoders,
Hu R, Tong J, Xi J, Guo Q, Yu Y.
europepmc   +4 more sources

A Novel Clutter Covariance Matrix Estimation Method Based on Feature Subspace for Space-Based Early Warning Radar

open access: yesIEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 2021
Accurate estimation of the clutter covariance matrix for the cell under test (CUT) is a committed step in the spatial-temporal adaptive processing (STAP) algorithm.
Tianfu Zhang   +5 more
doaj   +3 more sources

k-Covariance: An Approach of Ensemble Covariance Estimation and Undersampling to Stabilize the Covariance Matrix in the Global Minimum Variance Portfolio

open access: yesApplied Sciences, 2022
A covariance matrix is an important parameter in many computational applications, such as quantitative trading. Recently, a global minimum variance portfolio received great attention due to its performance after the 2007–2008 financial crisis, and this ...
Tuan Tran, Nhat Nguyen, Trung Nguyen
doaj   +1 more source

2D-DOA Estimation in Switching UCA Using Deep Learning-Based Covariance Matrix Completion

open access: yesSensors, 2022
In this paper, we study the two-dimensional direction of arrival (2D-DOA) estimation problem in a switching uniform circular array (SUCA), which means performing 2D-DOA estimation with a reduction in the number of radio frequency (RF) chains.
Ruru Mei   +3 more
doaj   +1 more source

DOA-Estimation Method Based on Improved Spatial-Smoothing Technique

open access: yesMathematics, 2023
To improve the data utilization of the sensor array and direction-of-arrival-(DOA)-estimation performance for coherent signals, a DOA-estimation method with a modified spatial-smoothing technique is proposed. The covariance matrix of the received data of
Yujun Hou   +4 more
doaj   +1 more source

The DOA Estimation Method for Low-Altitude Targets under the Background of Impulse Noise

open access: yesSensors, 2022
Due to the discontinuity of ocean waves and mountains, there are often multipath propagation effects and obvious pulse characteristics in low-altitude detection.
Bin Lin   +4 more
doaj   +1 more source

Covariance estimation via fiducial inference

open access: yesStatistical Theory and Related Fields, 2021
As a classical problem, covariance estimation has drawn much attention from the statistical community for decades. Much work has been done under the frequentist and Bayesian frameworks.
W. Jenny Shi   +3 more
doaj   +1 more source

Improved Large Dynamic Covariance Matrix Estimation With Graphical Lasso and Its Application in Portfolio Selection

open access: yesIEEE Access, 2020
The estimation of the large and high-dimensional covariance matrix and precision matrix is a fundamental problem in modern multivariate analysis. It has been widely applied in economics, finance, biology, social networks and health sciences. However, the
Xin Yuan   +3 more
doaj   +1 more source

Covariance Estimation: The GLM and Regularization Perspectives [PDF]

open access: yes, 2011
Finding an unconstrained and statistically interpretable reparameterization of a covariance matrix is still an open problem in statistics. Its solution is of central importance in covariance estimation, particularly in the recent high-dimensional data ...
Pourahmadi, Mohsen
core   +5 more sources

When do improved covariance matrix estimators enhance portfolio optimization? An empirical comparative study of nine estimators [PDF]

open access: yes, 2010
The use of improved covariance matrix estimators as an alternative to the sample estimator is considered an important approach for enhancing portfolio optimization.
Lillo, Fabrizio   +3 more
core   +2 more sources

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