Results 1 to 10 of about 556,837 (257)

Covariance Shaping Over Riemannian Manifolds for Massive MIMO Communication

IEEE Access, 2023
Acquiring accurate instantaneous channel state information (CSI) is a challenging aspect of massive multi-input multi-output (MIMO) communication. Utilizing statistical information, such as channel covariance matrix, to design statistical beamforming ...
Joarder Jafor Sadique, Imtiaz Nasim, Ahmed S. Ibrahim   +2 more
doaj   +1 more source

Linear Pooling of Sample Covariance Matrices [PDF]

IEEE Transactions on Signal Processing, 2022
We consider the problem of estimating high-dimensional covariance matrices of $K$-populations or classes in the setting where the sample sizes are comparable to the data dimension. We propose estimating each class covariance matrix as a distinct linear combination of all class sample covariance matrices.
Tyler, David E, Ollila, Esa, Raninen, Elias   +3 more
openaire   +3 more sources

Shrinkage Estimators for Covariance Matrices [PDF]

Biometrics, 2001
Estimation of covariance matrices in small samples has been studied by many authors. Standard estimators, like the unstructured maximum likelihood estimator (ML) or restricted maximum likelihood (REML) estimator, can be very unstable with the smallest estimated eigenvalues being too small and the largest too big.
Daniels, Michael J., Kass, Robert E.
openaire   +3 more sources

Multi-Modal Subspace Fusion via Cauchy Multi-Set Canonical Correlations

IEEE Access, 2020
Multi-set canonical correlation analysis (MCCA) is a famous multi-modal coherent subspace learning method. However, sample-based between-modal and within-modal covariance matrices of MCCA usually deviate from real covariance matrices due to noise ...
Yanmin Zhu, Tianhao Peng, Shuzhi Su, Changpeng Li   +3 more
doaj   +1 more source

A finite-difference method for linearization in nonlinear estimation algorithms [PDF]

Modeling, Identification and Control, 1998
Linearizations of nonlinear functions that are based on Jacobian matrices often cannot be applied in practical applications of nonlinear estimation techniques. An alternative linearization method is presented in this paper.
Tor S. Schei
doaj   +1 more source

Covariance Matrices and the Separability Problem [PDF]

Physical Review Letters, 2007
4 pages, no figures; v3: final version to appear in ...
Gühne, O., Hyllus, P., Gittsovich, O., Eisert, J.   +3 more
openaire   +4 more sources

Conservative Quantization of Covariance Matrices with Applications to Decentralized Information Fusion

Sensors, 2021
Information fusion in networked systems poses challenges with respect to both theory and implementation. Limited available bandwidth can become a bottleneck when high-dimensional estimates and associated error covariance matrices need to be transmitted ...
Christopher Funk, Benjamin Noack, Uwe D. Hanebeck   +2 more
doaj   +1 more source

On the Properties of Estimates of Monotonic Mean Vectors for Multivariate Normal Distributions [PDF]

Journal of Statistical Theory and Applications (JSTA), 2015
.Problems concerning estimation of parameters and determination the statistic, when it is known a priori that some of these parameters are subject to certain order restrictions, are of considerable interest.
Abouzar Bazyari
doaj   +1 more source

A Rigorous Feature Extraction Algorithm for Spherical Target Identification in Terrestrial Laser Scanning

Remote Sensing, 2022
Precise and rapid extraction of spherical target features from laser point clouds is critical for achieving high-precision registration of multiple point clouds.
Ronghua Yang, Jing Li, Xiaolin Meng, Yangsheng You   +3 more
doaj   +1 more source

Millimeter Wave Beamforming Codebook Design via Learning Channel Covariance Matrices Over Riemannian Manifolds

IEEE Access, 2022
Covariance matrices of spatially-correlated wireless channels in millimeter wave (mmWave) vehicular networks can be employed to design environment-aware beamforming codebooks.
Imtiaz Nasim, Ahmed S. Ibrahim
doaj   +1 more source