Convolutional Neural Networks for Direction of Arrival Estimation Compared to Classical Estimators and Bounds

Recently, there has been a proliferation of applied machine learning (ML) research, including the use of convolutional neural networks (CNNs) for direction of arrival (DoA) estimation. With the increasing amount of research in this area, it is important to balance the performance and computational c...

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Main Authors: Christopher J. Bell, Kaushallya Adhikari, Andrew Brown
Format: Article
Language:English
Published: IEEE 2025-01-01
Series:IEEE Access
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Online Access:https://ieeexplore.ieee.org/document/10872920/
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author Christopher J. Bell
Kaushallya Adhikari
Andrew Brown
author_facet Christopher J. Bell
Kaushallya Adhikari
Andrew Brown
author_sort Christopher J. Bell
collection DOAJ
description Recently, there has been a proliferation of applied machine learning (ML) research, including the use of convolutional neural networks (CNNs) for direction of arrival (DoA) estimation. With the increasing amount of research in this area, it is important to balance the performance and computational costs of CNNs with classical methods of DoA estimation such as Multiple Signal Classification (MUSIC). We outline the performance of both methods of DoA estimation for single-source and two-source cases for multiple array conditions. The results are also compared to the Cramer-Rao lower bound (CRLB) and conventional beamforming. For each source case, CNNs were trained for a perfect uniform line array (ULA) and tested against data from a perfect ULA, perturbed ULAs, ULAs with missing sensors, and ULAs with muffled sensors. We show that for the single-source case, the CNNs do not offer any performance improvement relative to MUSIC at low signal-to-noise ratio (SNR). For the two-source cases, the CNNs perform better than MUSIC but only at low SNR. For the remaining array cases, the CNNs outperform MUSIC. These results indicate that the performance improvements from CNNs are highest for situations where there is signal model to data mismatch (imperfect information). This work also illustrates that the CNN estimators developed in this work exceed the CRLB and are biased estimators caused by the lack of unbiased constraint in the loss function during training of the CNNs.
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spelling doaj-art-c2d4be49584c4aa18d7304c241136e6d2025-02-12T00:01:47ZengIEEEIEEE Access2169-35362025-01-0113255332554510.1109/ACCESS.2025.353899710872920Convolutional Neural Networks for Direction of Arrival Estimation Compared to Classical Estimators and BoundsChristopher J. Bell0https://orcid.org/0009-0005-6487-5038Kaushallya Adhikari1https://orcid.org/0000-0002-0706-0781Andrew Brown2https://orcid.org/0009-0004-1091-4989Department of Electrical, Computer and Biomedical Engineering, The University of Rhode Island, Kingston, RI, USADepartment of Electrical, Computer and Biomedical Engineering, The University of Rhode Island, Kingston, RI, USADepartment of Electrical, Computer and Biomedical Engineering, The University of Rhode Island, Kingston, RI, USARecently, there has been a proliferation of applied machine learning (ML) research, including the use of convolutional neural networks (CNNs) for direction of arrival (DoA) estimation. With the increasing amount of research in this area, it is important to balance the performance and computational costs of CNNs with classical methods of DoA estimation such as Multiple Signal Classification (MUSIC). We outline the performance of both methods of DoA estimation for single-source and two-source cases for multiple array conditions. The results are also compared to the Cramer-Rao lower bound (CRLB) and conventional beamforming. For each source case, CNNs were trained for a perfect uniform line array (ULA) and tested against data from a perfect ULA, perturbed ULAs, ULAs with missing sensors, and ULAs with muffled sensors. We show that for the single-source case, the CNNs do not offer any performance improvement relative to MUSIC at low signal-to-noise ratio (SNR). For the two-source cases, the CNNs perform better than MUSIC but only at low SNR. For the remaining array cases, the CNNs outperform MUSIC. These results indicate that the performance improvements from CNNs are highest for situations where there is signal model to data mismatch (imperfect information). This work also illustrates that the CNN estimators developed in this work exceed the CRLB and are biased estimators caused by the lack of unbiased constraint in the loss function during training of the CNNs.https://ieeexplore.ieee.org/document/10872920/Convolutional neural networkdirection of arrivalmultiple signal classificationCramer-Rao lower boundregressionperturbed array
spellingShingle Christopher J. Bell
Kaushallya Adhikari
Andrew Brown
Convolutional Neural Networks for Direction of Arrival Estimation Compared to Classical Estimators and Bounds
IEEE Access
Convolutional neural network
direction of arrival
multiple signal classification
Cramer-Rao lower bound
regression
perturbed array
title Convolutional Neural Networks for Direction of Arrival Estimation Compared to Classical Estimators and Bounds
title_full Convolutional Neural Networks for Direction of Arrival Estimation Compared to Classical Estimators and Bounds
title_fullStr Convolutional Neural Networks for Direction of Arrival Estimation Compared to Classical Estimators and Bounds
title_full_unstemmed Convolutional Neural Networks for Direction of Arrival Estimation Compared to Classical Estimators and Bounds
title_short Convolutional Neural Networks for Direction of Arrival Estimation Compared to Classical Estimators and Bounds
title_sort convolutional neural networks for direction of arrival estimation compared to classical estimators and bounds
topic Convolutional neural network
direction of arrival
multiple signal classification
Cramer-Rao lower bound
regression
perturbed array
url https://ieeexplore.ieee.org/document/10872920/
work_keys_str_mv AT christopherjbell convolutionalneuralnetworksfordirectionofarrivalestimationcomparedtoclassicalestimatorsandbounds
AT kaushallyaadhikari convolutionalneuralnetworksfordirectionofarrivalestimationcomparedtoclassicalestimatorsandbounds
AT andrewbrown convolutionalneuralnetworksfordirectionofarrivalestimationcomparedtoclassicalestimatorsandbounds