Preprints Journal Conference Book chapters Theses Other


Preprints

Simultaneous penalized M-estimation of covariance matrices using geodesically convex optimization
Esa Ollila, Ilya Soloveychik, David E. Tyler, and Ami Wiesel, arXiv:1608.08126 [stat.ME], Aug. 2016.

Asymptotics of ICA estimators and their performance indices
Pauliina Ilmonen, Klaus Nordhausen, Hannu Oja and Esa Ollila, arXiv:1212.3953 [stat.ME], Dec. 2012.

The equality between the Stochastic CRB and its semiparametric version for elliptical data
Stefano Fortunati and Esa Ollila, HAL Id: hal-04461267, Feb. 2024.

Sparse signal recovery and source localization via covariance learning
Esa Ollila, arXiv:2401.13975 [stat.ME], Jan. 2024.

Activity Detection for Massive Random Access using Covariance-based Matching Pursuit
Leatile Marata, Esa Ollila, and Hirley Alves, arXiv:2405.02741 [eess.SP], May. 4, 2024.

Journal papers

Graph Convolutional Neural Networks Sensitivity under Probabilistic Error Model
Xinjue Wang, Esa Ollila and Sergiy A. Vorobyov
IEEE Transactions on Signal and Information Processing over Networks, p. 1-16, 2024. (early access)
[doi] [pdf]

Greedy Capon Beamformer
Esa Ollila
IEEE Signal Processing Letters, vol. 31, pp. 2775 - 2779, 2024.
[doi] [code] [pdf]

Robust and Sparse M-Estimation of DOA
Christoph F. Mecklenbräuker, Peter Gerstoft, Esa Ollila, Yongsung Park
Signal Processing, Vol. 220, 109461, 2024.
[doi] [code]

Affine equivariant Tyler's M-estimator applied to tail parameter learning of elliptical distributions
Esa Ollila, Daniel P. Palomar and Frederic Pascal
IEEE Signal Processing Letters, 2023.
[R package] [pdf]

New Robust Sparse Convolutional Coding Inversion Algorithm for Ground Penetrating Radar Images
Matthieu Gallet, Ammar Mian, Guillaume Ginolhac, Esa Ollila, and Nickolas Stelzenmuller
IEEE Transactions on Geoscience and Remote Sensing, vol. 63, 2023, 5103814.
[Python toolbox]

Multimodal image fusion via coupled feature learning
Farshad G. Veshki, Nora Ouzir, Sergiy A. Vorobyov, and Esa Ollila
Signal Processing, Volume 200, Nov. 2022, 108637.
[Matlab toolbox]

Regularized tapered sample covariance matrix
Esa Ollila and Arnaud Breloy
IEEE Transactions on Signal Processing, vol. 70, pp. 2306-2320, 2022
[Matlab toolbox]

Linear pooling of sample covariance matrices
Elias Raninen, David E. Tyler, and Esa Ollila
IEEE Transactions on Signal Processing, vol. 70, pp. 659-672, 2021.
[Matlab toolbox] [arxiv]

Bias adjusted sign covariance matrix
Elias Raninen and Esa Ollila
IEEE Signal Processing Letters, vol. 29, pp. 339 - 343, 2021
[Matlab toolbox][pdf]

Coupled regularized sample covariance matrix estimator for multiple classes
Elias Raninen and Esa Ollila
IEEE Transactions on Signal Processing, vol. 69, pp. 5681-5692, 2021
[pdf] [Matlab toolbox] [arxiv]

On the variability of the sample covariance matrix under complex elliptical distributions
Elias Raninen and Esa Ollila
IEEE Signal Processing Letters, vol. 28, pp. 2092-2096, 2021.
[pdf] [arxiv]

Modelling and studying the effect of graph errors in graph signal processing
Jari Miettinen, Sergiy A. Vorobyov, and Esa Ollila
Signal Processing, vol. 189, December 2021, 108256

Graph signal processing meets blind source separation
Jari Miettinen, Eyal Nitzan, Sergiy A. Vorobyov, and Esa Ollila
IEEE Transactions on Signal Processing, vol 69, pp. 2585-2599, 2021.
[arxiv]

Shrinking the eigenvalues of M-estimators of covariance matrix
Esa Ollila, Daniel P. Palomar and Frederic Pascal
IEEE Transactions on Signal Processing, vol. 69, pp. 256-269, 2021.
[Matlab toolbox] [arxiv]

A compressive classification framework for high-dimensional data
Muhammad Naveed Tabassum and Esa Ollila
IEEE Open Journal of Signal Processing, vol. 1, pp. 177-186, 2020
[Matlab toolbox] [arxiv] [pdf]

Data-Adaptive Similarity Measures for B-mode Ultrasound Images Using Robust Noise Models
Nora Ouzir, Esa Ollila and Sergiy Vorobyov
IEEE Journal of Selected Topics in Signal Processing, vol. 14, no. 6, pp. 1244-1254, 2020.

Optimal shrinkage covariance matrix estimation under random sampling from elliptical distributions
Esa Ollila and Elias Raninen
IEEE Transactions on Signal Processing, vol. 67, no. 10, pp. 2707 - 2719, 2019.
[Matlab toolbox] [arxiv]

Sequential adaptive elastic net approach for single-snapshot source localization
Muhammad Naveed Tabassum and Esa Ollila
Journal of the Acoustical Society of America, vol. 146, no. 6, pp. 3873-3882, 2018.
[Matlab toolbox] [arxiv]

Alternative derivation of FastICA with novel power iteration algorithm
Shahab Basiri, Esa Ollila and Visa Koivunen
IEEE Signal Processing Letters, vol. 24, no 9, 2017.
[Matlab toolbox] [pdf]

Enhanced bootstrap method for statistical inference in the ICA model
Shahab Basiri, Esa Ollila and Visa Koivunen
Signal Processing, vol. 138, pp. 53-62, 2017.
[software]

Robust, scalable and fast bootstrap method for analyzing large scale data
Shahab Basiri, Esa Ollila and Visa Koivunen
IEEE Transactions on signal processing, vol. 64, no. 4, pp. 1007-1017, 2016. [arxiv]

Regularized M-estimators of scatter matrix
Esa Ollila and David E. Tyler
IEEE Transactions on signal processing, vol. 62, no. 22, pp. 6059-6070, 2014. [pdf]

On applicability of PCA, voxel-wise variance normalization and dimensionality assumptions for sliding temporal window sICA in resting-state fMRI
Jukka J. Remes, Ahmed Abou Elseoud, Esa Ollila, et al.
Magnetic Resonance Imaging vol. 31, no. 8, pp. 1338-1348, 2013.

Compound-Gaussian clutter modelling with an inverse Gaussian texture distribution
Esa Ollila, David E. Tyler, Visa Koivunen and H. Vincent Poor
IEEE Signal Processing Letters, vol. 19, no. 12, pp. 876-879, 2012.

Complex elliptically symmetric distributions: survey, new results and applications
Esa Ollila, David E. Tyler, Visa Koivunen and H. Vincent Poor
IEEE Transactions on signal processing, vol. 60, no. 11, pp. 5597-5625, 2012.

On testing the extent of noncircularity
Michael Novey, Esa Ollila and Tülay Adali
IEEE Transactions on signal processing, vol. 59, no. 11, pp. 5632-5637, 2011.

Complex elliptically symmetric random variables - generation, characterization and circularity tests
Esa Ollila, Jan Eriksson and Visa Koivunen
IEEE Transactions on signal processing, vol. 59, no.1, pp. 58-69, 2011.

Effects of repeatibility measures on results of fMRI sICA: a study on simulated and real resting-state effects
Jukka J. Remes, Tuomo Starck, Juha Nikkinen, Esa Ollila, Christian F. Beckmann, Osmo Tervonen, Vesa Kiviniemi, Olli Silven
NeuroImage, vol. 56, no. 2, pp. 554-569, 2011

Essential statistics and tools for complex random variables
Jan Eriksson, Esa Ollila and Visa Koivunen
IEEE Transactions on signal processing, vol. 58, no. 10, pp. 5400-5408, 2010.

The deflation-based FastICA estimator: statistical analysis revisited
Esa Ollila
IEEE Transactions on Signal Processing, vol. 58, no. 3, pp. 1527-1541, 2010.

Complex ICA using generalized uncorrelating transform
Esa Ollila and Visa Koivunen
Signal Processing, vol. 89, no. 4, pp. 365-377, 2009.

Influence function and asymptotic efficiency of scatter matrix based array processors: case MVDR beamformer
Esa Ollila and Visa Koivunen
IEEE Transactions on Signal Processing, vol. 57, no. 1, pp. 247-259, 2009. [software]

On the circularity of a complex random variable
Esa Ollila
IEEE Signal Processing Letters, vol. 15, pp. 841-844, 2008. [pdf]

Compact Cramer-Rao bound expression for independent component analysis
Esa Ollila, Hyon-Jung Kim and Visa Koivunen
IEEE Transactions on Signal Processing, vol. 56, no. 4, pp. 1421-1428, 2008. [pdf]

Robust independent component analysis based on two scatter matrices
Klaus Nordhausen, Hannu Oja and Esa Ollila
Austrian Journal of Statistics, vol. 37, no. 1, pp. 91-100, 2008. [pdf]

Complex-valued ICA based on a pair of generalized covariance matrices
Esa Ollila, Hannu Oja and Visa Koivunen
Computational Statistics and Data Analysis , vol. 52, no. 7, pp. 3789-3805, 2008.

Stochastic maximum-likelihood method for MIMO propagation parameter estimation
Cassio Ribeiro, Esa Ollila and Visa Koivunen
IEEE Transactions on Signal Processing, vol. 55, no. 1, pp. 46-55, 2007.

Influence functions and efficiencies of the canonical correlation and vector estimates based on scatter and shape matrices
Sara Taskinen, Christophe Croux, Annaliisa Kankainen, Esa Ollila and Hannu Oja
Journal of Multivariate Analysis, vol. 97, no. 2, pp. 359-384, 2006.

Influence function and asymptotic efficiency of the affine equivariant rank covariance matrix
Esa Ollila, Christophe Croux and Hannu Oja
Statistica Sinica, vol. 14, no. 1, pp. 297-316, 2004. [pdf]

Estimates of regression coefficients based on lift rank covariance matrix
Esa Ollila, Hannu Oja and Visa Koivunen
Journal of the American Statistical Association, vol. 98, no. 461, pp. 90-98, 2003. [software]

Affine equivariant multivariate rank methods
Samuli Visuri, Esa Ollila, Visa Koivunen, Jyrki Mottonen and Hannu Oja
Journal of Statistical Planning and Inference, vol. 114, no. 1-2, pp. 161-185, 2003.

The affine equivariant sign covariance matrix: asymptotic behavior and efficiencies
Esa Ollila, Hannu Oja and Christophe Croux Journal of Multivariate Analysis, vol. 87, no. 2, pp. 328-355, 2003.

Estimates of regression coefficients based on sign covariance matrix
Esa Ollila, Thomas P. Hettmansperger and Hannu Oja
Journal of the Royal Statistical Society, Ser. B, vol. 64, no. 3, pp. 447-466, 2002.

Conference papers

Matching Pursuit Covariance Learning
Esa Ollila
Proc. 32nd European Signal Processing Conference (EUSIPCO'24), Lyon, August 26-30, 2024, pp. 2447-2451.
[code] [pdf] [slides]

Nonnegative structured Kruskal tensor regression
Xinjue Wang, Esa Ollila, and Sergiy A. Vorobyov
Proc. IEEE International Workshop on Computational Advances in Multi-Sensor Adaptive Processing (CAMSAP'23), Dec 10-13, Los Suenos, Costa Rica, 2023.

Sparsity-aware block diagonal representation for subspace clustering
Aylin Tastan, Michael Muma, Esa Ollila, and Abdelhak M. Zoubir
Proc. 31st European Signal Processing Conference (EUSIPCO'23), Helsinki, Finland, Sept. 4-8, 2023, pp. 1594-1598.
[pdf]

Correlation-based graph smoothness measures in graph signal processing
Jari Miettinen, Sergiy A. Vorobyov, Esa Ollila, and Xinjue Wang Proc. 31st European Signal Processing Conference (EUSIPCO'23), Helsinki, Finland, Sept. 4-8, 2023,pp. 1848-1852.
[pdf]

Robust sparse Bayesian learning for DOA
Christoph F. Mecklenbrauker, Peter Gerstoft, Esa Ollila, and Yongsung Park
Proc. 31st European Signal Processing Conference (EUSIPCO'23), Helsinki, Finland, Sept 4-8, 2023, pp. 1788-1792.
[pdf]

Regularized EM algorithm
Pierre Houdouin, Esa Ollila, and Frederic Pascal
Proc. IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP'23), Rhodes Island, June 4-10, 2023

Graph Neural Network Sensitivity Under Probabilistic Error Model
Xinjue Wang, Esa Ollila, and Sergiy A. Vorobyov
Proc. 30th European Signal Processing Conference (EUSIPCO'22), Belgrade, Serbia, Aug. 29 - Sept.2, 2022, pp. 2146-2150.
[pdf]

Robust tensor regression with applications in imaging
Esa Ollila and Hyon-Jung Kim
Proc. 30th European Signal Processing Conference (EUSIPCO'22), Belgrade, Serbia, Aug. 29 - Sept.2, 2022, pp. 887-891.
[pdf]

DOA M-estimation using sparse Bayesian learning
Christoph F. Mecklenbrauker, Peter Gerstoft, and Esa Ollila
Proc. IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP'22), Singapore, May 22-27, 2022, p. 4933-4937.

Qualitatively Robust Bayesian Learning for DOA from Array Data using M-Estimation of the Scatter Matrix
Christoph F. Mecklenbrauker, Peter Gerstoft, and Esa Ollila
Proc. 25th International ITG Workshop on Smart Antennas (WSA 2021), EURECOM, French Riviera, Nov. 10-12, 2021, pp. 179-184.

Improved estimation of the degree of freedom parameter of multivariate t-distribution
Frederic Pascal, Esa Ollila, and Daniel P. Palomar
Proc. 29th European Signal Processing Conference (EUSIPCO'21), Dublin, Ireland, August 23-27, 2021, pp. 860-864.
[pdf]

Robust registration of multi-modal medical images using Huber's criterion
Nora Ouzir, Eesa Ollila, and Sergiy A. Vorobyov
Proc. 54th Annual Asilomar Conf. Signals, Systems, and Computers (ASILOMAR), Pacific Grove, California, USA, Nov. 1-4, 2020, pp. 773-777.

Block-wise minimization-majorization algorithm for Huber's criterion: sparse learning and applications
Esa Ollila and Ammar Mian
Proc. IEEE International Workshop on Machine Learning for Signal Processing (MLSP'20), Sep 21-24, 2020, Espoo, Finland, pp. 1--6.
[arxiv] [Toolbox] [Slides]

A comparative study of supervised learning algorithms for symmetric positive definite features
Ammar Mian, Elias Raninen and Esa Ollila
Proc. 28th European Signal Processing Conference (EUSIPCO'20), Amsterdam, Netherlands, August 24-28, 2020, pp. 950--954.
[pdf] [Python toolbox]

M-estimators of scatter with eigenvalue shrinkage
Esa Ollila, Daniel P. Palomar and Frederic Pascal
Proc. IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP'20), Barcelona, Spain, May 4-9, 2020, pp. 5305-5309.
[arxiv] [Matlab toolbox]

Blind source separation of graph signals
Jari Miettinen, Sergiy A. Vorobyov, and Esa Ollila
Proc. IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP'20), Barcelona, Spain, May 4-9, 2020, pp. 5645-5649.

Spectral Shrinkage of Tyler's M-Estimator of Covariance Matrix
Arnaud Breloy, Esa Ollila, and Frederic Pascal
Proc. IEEE International Workshop on Computational Advances in Multi-Sensor Adaptive Processing (CAMSAP'19), Dec 15-18, Guadeloupe, West Indies, 2019, pp. 535-538. [pdf]

ML-based Motion Estimation in Ultrasound Images Using Heavy-tailed Noise Distributions
Nora Ouzir, Esa Ollila, and Sergiy Vorobyov
Proc. IEEE International Workshop on Computational Advances in Multi-Sensor Adaptive Processing (CAMSAP'19), Dec 15-18, Guadeloupe, West Indies, 2019, pp. 366-370.

Fusing eigenvalues
Shahab Basiri, Esa Ollila, Gordana Draskovic and Frederic Pascal
Proc. IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP'19), May 12 - 17, Brighton, UK, 2019, pp. 4968 -4972.

Robust least mean squares estimation of graph signals
Jari Miettinen, Sergiy A. Vorobyov and Esa Ollila
Proc. IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP'19), May 12 - 17, Brighton, UK, 2019, pp. 5416-5420.

Simultaneous signal subspace rank and model selection with an application to single snapshot source localization
Muhammad Naveed Tabassum and Esa Ollila
Proc. 26th European Signal Processing Conference (EUSIPCO'18), Rome, Italy, Sep 3-9, 2018, pp. 1592 - 1596. [arxiv] [Matlab package]

Graph error effect in graph signal processing
Jari P. Miettinen, Sergiy A. Vorobyov and Esa Ollila
Proc. IEEE International Conference on Acoustics, Speech and Signal Processinh (ICASSP'18), Calgary, Canada, Apr 15-20, 2018, pp. 4164-4168.

Optimal pooling of covariance matrix estimates across multiple classes
Elias Raninen and Esa Ollila
Proc. IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP'18), Calgary, Canada, Apr 15-20, 2018, pp. 4224-4228. [poster]

Compressive regularized discriminant analysis of high-dimensional data with applications to microarray studies
Muhammad Naveed Tabassum and Esa Ollila
Proc. IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP'18), Calgary, Canada, Apr 15-20, 2018, pp. pp. 4204-4208. [poster]

Optimal high-dimensional shrinkage covariance estimation for elliptical distributions
Esa Ollila
Proc. 25th European Signal Processing Conference (EUSIPCO'17), Kos, Greece, Aug 28 - Sep 2, 2017, pp. 1689-1693.

Pathwise Least Angle Regression and a Significance Test for the Elastic Net
Muhammad Naveed Tabassum and Esa Ollila
Proc. 25th European Signal Processing Conference (EUSIPCO'17), Kos, Greece, Aug 28 - Sep 2, 2017, pp. 1349-1353.

Scaled and square-root Elastic Net
Elias Raninen and Esa Ollila
Proc. IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP'17), New Orleans, USA, March 5-9, 2017, pp. 4336-4340.

Single-snapshot DoA estimation using adaptive elastic net in the complex domain
Muhammad Naveed Tabassum and Esa Ollila
Proc. Int'l Workshop on Compressed Sensing Theory and its Applications to Radar, Sonar and Remote Sensing (CoSeRa'16), Aachen, Germany, Sep 19-22, 2016, pp. 202-206.

Adaptive LASSO based on joint M-estimation of regression and scale
Esa Ollila
Proc. 24th European Signal Processing Conference (EUSIPCO'16), Budapest, Hungary, Aug 29 - Sep 2, 2016, pp. 2191-2195.

Direction of arrival estimation using robust complex Lasso
Esa Ollila
Proc. 10th European Conference on Antennas and Propagation (EuCAP'16), Davos, Switzerland, Apr 10 - 15, 2016. [pdf]

Randomized Simultaneous Orthogonal Matching Pursuit
Aqib Ejaz, Esa Ollila and Visa Koivunen
Proc. 23rd European Signal Processing Conference (EUSIPCO'15), Nice, France, Aug 31- Sep 4, 2015, pp. 709-713.

New robust LASSO method based on ranks
Hyon-Jung Kim, Esa Ollila and Visa Koivunen
Proc. 23rd European Signal Processing Conference (EUSIPCO'15), Nice, France, Aug 31- Sep 4, 2015, pp. 704-708.

Nonparametric simultaneous sparse recovery: an application to source localization
Esa Ollila
Proc. 23rd European Signal Processing Conference (EUSIPCO'15), Nice, France, Aug 31- Sep 4, 2015, pp. 509-513. [arxiv]

Multichannel sparse recovery of complex-valued signals using Huber's criterion
Esa Ollila
Proc. Int'l Workshop on Compressed Sensing Theory and its Applications to Radar, Sonar and Remote Sensing (CoSeRa'15), Pisa, Italy, June 16-19, 2015, pp. 32-36. [software]

Fast and Robust Bootstrap in Analysing Large Multivariate Datasets
Shahab Basiri, Esa Ollila and Visa Koivunen
Proc. Asilomar Conference on Signals, Systems, and Computer (Asilomar'14), Pacific Grove, CA, USA, Nov 2-5, 2014, pp. 8-13.

Robust iteratively reweighted LASSO estimation for sparse tensor factorizations
Hyon-Jung Kim, Esa Ollila, Visa Koivunen and H. Vincent Poor
Proc. IEEE Workshop on Statistical Signal Processing (SSP'14), Gold Coast, Australia, Jun 29-Jul 2, 2014, pp. 452-455.

Robust iterative hard thresholding for compressed sensing
Esa Ollila, Hyon-Jung Kim and Visa Koivunen
Proc. International Symposium on Communications, Control, and Signal Processing (ISCCSP 2014), Athens, Greece, May 21-23, 2014, pp. 226-229.

Fast and robust bootstrap method for testing hypotheses in the ICA model
Shahab Basiri, Esa Ollila and Visa Koivunen
Proc. IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP'14), Florence, Italy, May 4-9, 2014, pp. 6-10.

Robust and sparse estimation of tensor decompositions
Hyon-Jung Kim, Esa Ollila and Visa Koivunen
Proc. IEEE Global Conference on Signal and Information Processing (GlobalSIP'13), Austin, USA, Dec 3 - 5, 2013, pp. 965-968.

Robust regularized M-estimators of regression parameters and covariance matrix
Esa Ollila, Hyon-Jung Kim and Visa Koivunen
Proc. International Workshop on Advances in Regularization, Optimization, Kernel Methods and Support Vector Machines (ROKS'13) Leuven, Belgium, July 8-10, 2013, pp. 67-68.

Sparse regularization of tensor decompositions
Hyon-Jung Kim, Esa Ollila and Visa Koivunen
Proc. IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP'13), Vancouver, Canada, May 26-31, 2013, pp. 3836-3840.

Robust Greedy Algorithms for Compressed Sensing
S. Alireza Razavi, Esa Ollila and Visa Koivunen
Proc. 20th European Signal Processing Conference (EUSIPCO'12) , Bucharest, Romania, Aug. 28-31, 2012, pp. 969-973.

Distribution-free detection under complex elliptically symmetric clutter distribution
Esa Ollila and David E. Tyler
Proc. 7th IEEE Sensor Array and Multichannel Signal Processing Workshop (SAM'12), Hoboken, NJ, USA, June 17-20, 2012, pp. 413-416.

Deflation-based FastICA reloaded
Klaus Nordhausen, Pauliina Ilmonen, Abhijit Mandal, Hannu Oja and Esa Ollila
The 19th European Signal Processing Conference (EUSIPCO'11), Barcelona, Spain, Aug. 29-Sep. 2, 2011, pp. 1854-1858. [pdf]

On the performance indices of ICA and blind source separation
Klaus Nordhausen, Esa Ollila and Hannu Oja
Proc. 12th IEEE Int. Workshop on Signal Processing Advances for Wireless Communications (SPAWC'11), San Fransisco, CA, June 26-29, 2011, pp. 461-465.

A robust estimator and detector of circularity of complex signals
Esa Ollila, Visa Koivunen and H. Vincent Poor
Proc. IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP'11), Prague, Czech republic, May 22 - 27, 2011, pp. 3620-3623.

On testing hypothesis of mixing vectors in the ICA model using FastICA
Esa Ollila and Hyon-Jung Kim
Proc. IEEE International Symposium on Biomedical Imaging (ISBI'11), Chicago, USA, Mar. 30 - Apr. 2, 2011, pp. 325-328.

Complex-valued signal processing - essential models, tools and statistics
Esa Ollila, Visa Koivunen and H. Vincent Poor
Proc. Information Theory and Applications Workshop (ITA'11), San Diego, USA, Feb 6 - 11, 2011, pp. 1-10.

A new performance index for ICA: properties, computation and asymptotic analysis
Pauliina Ilmonen, Klaus Nordhausen, Hannu Oja and Esa Ollila
Latent Variable Analysis and Signal Separation (LVA/ICA'10), Eds. V. Vigneron, V. Zarzoso, E. Moreau, R. Gribonval, and E. Vincent, Heidelberg: Springer, 2010, pp. 229-236.

On the robustness of the deflation-based FastICA estimator
Esa Ollila
Proc. IEEE Workshop on Statistical Signal Processing (SSP'09), Cardiff, Wales UK, Aug. 31-Sept. 3, 2009, pp. 673-676.

Adjusting the generalized likelihood ratio test of circularity robust to non-normality
Esa Ollila and Visa Koivunen
Proc. 10th IEEE Int.'l Workshop on Signal Processing Advances in Wireless Communications (SPAWC'09), Perugia, Italy, June 21-24, 2009, pp. 558 - 562. [pdf]  [software]

Statistics for complex random variables revisited
Jan Eriksson, Esa Ollila and Visa Koivunen
Proc. IEEE Int.'l Conference on Acoustics, Speech and Signal Processing (ICASSP'09), Taipei, Taiwan, April 19-24, 2009, pp. 3565 - 3568. [pdf]

On the Cramer-Rao bound for the constrained and unconstrained complex parameters
Esa Ollila, Visa Koivunen and Jan Eriksson
Proc. IEEE Sensor Array and Multichannel Signal Processing Workshop (SAM'08), Darmstadt, Germany, July 21-23, 2008, pp. 414-418. [pdf]

Robust ICA based on two scatter matrices
Klaus Nordhausen, Hannu Oja and Esa Ollila
Proc. Int.'l Conference on Computer Data Analysis and Modeling (CDAM'07), Minsk, Belarus, Sep. 11-15, 2007, pp. 84-91.

Propagation parameter estimation in MIMO systems using mixture of angular distributions model
Cassio Ribeiro, Esa Ollila and Visa Koivunen
Proc. IEEE Int.'l Conference on Acoustics, Speech, and Signal Processing (ICASSP'05), Philadelphia, USA, Mar. 18-23, 2005, vol. 4, pp. 885 - 888.

Generalized complex elliptical distributions
Esa Ollila and Visa Koivunen
Proc. IEEE Sensor Array and Multichannel Signal Processing Workshop (SAM'04), Sitges, Spain, July 18-21, 2004, pp. 460-464. [pdf]

Cramer-Rao bound for angular propagation parameter estimation in MIMO systems
Cassio Ribeiro, Esa Ollila and Visa Koivunen
Proc. Asilomar Conference on Signals, Systems, and Computers, Pacific Grove, USA, Nov. 7-10, 2004, vol. 2, pp. 1785-1789.

Stochastic maximum likelihood method for propagation parameter estimation
Cassio Ribeiro, Esa Ollila and Visa Koivunen
Proc. IEEE Int.'l Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC'04), Barcelona, Spain, Sept. 5-8, 2004, vol. 3, pp. 1839 -1843.

Robust space-time scatter matrix estimator for broadband antenna arrays
Esa Ollila and Visa Koivunen
Proc. IEEE Vehicular Technology Conference (VTC'03-Fall), Orlando, USA, Oct. 6-9, 2003, vol. 1, pp. 55-59.

Influence functions for array covariance matrix estimators
Esa Ollila and Visa Koivunen
Proc. IEEE Workshop on Statistical Signal Processing (SSP'03), St. Louis, USA, Sept. 28-Oct. 1, 2003, pp. 445-448.

Robust antenna array processing using M-estimators of pseudo-covariance
Esa Ollila and Visa Koivunen
Proc. IEEE Int.'l Symp. Personal, Indoor and Mobile Radio Communications (PIMRC'03), Beijing, China, Sept. 7-10, 2003, vol. 3, pp. 2659-2663. [pdf]

Book chapters (refereed)

Linear shrinkage of sample covariance matrix or matrices under elliptical distributions: a review
Esa Ollila
Chapter in Elliptically Symmetric Distributions in Signal Processing and Machine Learning , Eds. Jean-Pierre Delmas, Mohammed Nabil El Korso, Stefano Fortunati, and Frederic Pascal, May 2024, Springer, Switzerland.
[ArXiv]

On robust estimators of sphericity measure in high-dimension
Esa Ollila and Hyon-Jung Kim
Chapter in Robust and Multivariate Statistical Methods: Festschrift in Honor of David E. Tyler, Jan 2022. Mengxi Yi and Klaus Nordhausen (eds.), May 2023, Springer, Switzerland, Cham.

Robust Simultaneous Sparse Approximations
Esa Ollila
Chapter 26, in Modern Nonparametric, Robust and Multivariate Methods, Eds. K. Nordhausen and S. Taskinen, pp. 471- 489, Heidelberg: Springer, 2015.
ISBN 978-3-319-22403-9.

Robust Compressive Sensing
Esa Ollila, Hyon-Jung Kim and Visa Koivunen
Chapter 10 in Regularization, Optimization, Kernels, and Support Vector Machines,
Eds. J.A.K. Suykens, M. Signoretto, A. Argyriou, pp. 217-236, Chapman and Hall, 2014. ISBN 978-1-48-224139-6.

Model order selection
Visa Koivunen and Esa Ollila
Chapter in Academic Press Library in Signal Processing, Volume 3: Array and Statistical Signal Processing, Eds. S. Theodoridis and R. Chellappa, pp. 9-26, Oxford, UK: Elsevier, 2014. ISBN 978-0-12-411597-2.

Multivariate models and the first four moments
Klaus Nordhausen, Hannu Oja and Esa Ollila
in Nonparametric Statistics and Mixture Models: A Festschrift in Honor of Thomas P. Hettmansperger, Eds. D. Hunter, D. Richards, J. L. Rosenberger, pp. 267-287, Signapore: World Scientific, 2011. ISBN-13 978-981-4340-55-7.

Robust estimation techniques for complex-valued random vectors
Esa Ollila and Visa Koivunen
Chapter 2 in Adaptive Signal Processing: Next Generation Solutions, Eds. T. Adali and S. Haykin, pp. 89-141, Hoboken, NJ: Wiley, 2010. ISBN-13: 978-0470195178

Direction-of-arrival estimation under uncertainty
Visa Koivunen and Esa Ollila
Chapter 12 in Advances in Direction-of-Arrival Estimation, Ed. S. Chandran, pp. 241-256, Boston, MA: Artech house, 2005. ISBN: 9781596930049

Robust ML-estimation of the transmitter location
Esa Ollila and Visa Koivunen
Theory and Applications of Recent Robust Methdos, Eds. M. Hubert, G. Pison, A. Struyf and S. Van Aelst, Series: Statistics for Industry and Technology, pp. 247 - 258, Basel: Birkhauser, 2004. ISBN 978-3-0348-7958-3.

Sign and rank covariance matrices: statistical properties and application to principal components analysis
Christophe Croux, Esa Ollila and Hannu Oja
Statistical Data Analysis Based on the L1-norm and Related Methods, Ed. Y. Dodge, pp. 257-271, Basel: Birkhauser, 2002. ISBN: 978-3-0348-9472-2.


Theses

Contributions to independent component analysis, sensor array and complex-valued signal processing
Esa Ollila, D.Sc. (Tech.) thesis, Aalto University, Department of Signal Processing and Acoustics, Report 14, overview 106 pages + articles, 2010. ISBN 978-952-60-3030-2. [pdf]

Sign and rank covariance matrices with applications to multivariate analysis
Esa Ollila, Ph.D. (Stat.) thesis, University of Jyväskylä, Department of Mathematics and Statistics, Report 85, overview 42 pages + articles, 2002. ISBN 978-951-39-1257-4. [pdf]

Analysis of chaotic signals
Esa Ollila, M.Sc. Thesis (Math.), Oulu University, Department of Mathematical Sciences, 90 pages, 1998.


Other

Affine equivariant multivariate sign methods
Esa Ollila, Thomas P. Hettmansperger and Hannu Oja, Preprint, University of Jyväskylä, 2004.

Robust Signal Processing for Smart Antennas
Visa Koivunen, Esa Ollila and Samuli Visuri, Proc. Seminar on Signal Processing Advances and Smart Antenna Systems, Helsinki, Finland, Oct. 7-8, 2003, pp. 1-14 (Available in CD-format).

Robust space-time covariance estimation for smart antennas
Esa Ollila, Luca Quattropani and Visa Koivunen, Proc. NATO RTO/SET Symposium on Smart and Adaptive Antennas, Chester, England, Apr. 7-9, 2003, pp. 1-7 (Available in CD-format).