20 citations · 80 across the 24 of their papers we have counts for
24 papers
GNSS Array-Based Multipath Detection Employing UKF on Manifolds
Abdelgabar Ahmed, Tarig Ballal, Xing Liu +2
Global Navigation Satellite Systems (GNSS) applications are often hindered by various sources of error, with multipath interference being one of the most challenging, particularly…
Regularized Linear Discriminant Analysis Using a Nonlinear Covariance Matrix Estimator
Maaz Mahadi, Tarig Ballal, Muhammad Moinuddin +2
Linear discriminant analysis (LDA) is a widely used technique for data classification. The method offers adequate performance in many classification problems, but it becomes ineffi…
Attitude Determination in Urban Canyons: A Synergy between GNSS and 5G Observations
Pinjun Zheng, Xing Liu, Tarig Ballal +1
This paper considers the attitude determination problem based on the global navigation satellite system (GNSS) and fifth-generation (5G) measurement fusion to address the shortcomi…
Beamforming Design and Performance Evaluation for RIS-aided Localization using LEO Satellite Signals
Lei Wang, Pinjun Zheng, Xing Liu +2
The growing availability of low-Earth orbit (LEO) satellites, coupled with the anticipated widespread deployment of reconfigurable intelligent surfaces (RISs), opens up promising p…
JrCUP: Joint RIS Calibration and User Positioning for 6G Wireless Systems
Pinjun Zheng, Hui Chen, Tarig Ballal +3
Reconfigurable intelligent surface (RIS)-assisted localization has attracted extensive attention as it can enable and enhance localization services in extreme scenarios. However, m…
5G-Aided RTK Positioning in GNSS-Deprived Environments
Pinjun Zheng, Xing Liu, Tarig Ballal +1
This paper considers the localization problem in a 5G-aided global navigation satellite system (GNSS) based on real-time kinematic (RTK) technique. Specifically, the user's positio…
Misspecified Cramér-Rao Bound of RIS-aided Localization under Geometry Mismatch
Pinjun Zheng, Hui Chen, Tarig Ballal +2
In 5G/6G wireless systems, reconfigurable intelligent surfaces (RIS) can play a role as a passive anchor to enable and enhance localization in various scenarios. However, most exis…
Localization Coverage Analysis of THz Communication Systems with a 3D Array
Pinjun Zheng, Tarig Ballal, Hui Chen +2
This paper considers the problem of estimating the position and orientation of a user equipped with a three-dimensional (3D) array receiving downlink far-field THz signals from mul…
Antenna Selection in Switch-Based MIMO Arrays via DOA threshold region Approximation
Hui Chen, Tarig Ballal, Mohammed E. Eltayeb +1
Direction-of-arrival (DOA) information is vital for multiple-input-multiple-output (MIMO) systems to complete localization and beamforming tasks. Switched antenna arrays have recen…
Instantaneous GNSS Ambiguity Resolution and Attitude Determination via Riemannian Manifold Optimization
Xing Liu, Tarig Ballal, Mohanad Ahmed +1
We present an ambiguity resolution method for Global Navigation Satellite System (GNSS)-based attitude determination. A GNSS attitude model with nonlinear constraints is used to ri…
Sharp Analysis of RLS-based Digital Precoder with Limited PAPR in Massive MIMO
Xiuxiu Ma, Abla Kammoun, Ayed M. Alrashdi +3
This paper focuses on the performance analysis of a class of limited peak-to-average power ratio (PAPR) precoders for downlink multi-user massive multiple-input multiple-output (MI…
Portfolio Optimization Using a Consistent Vector-Based MSE Estimation Approach
Maaz Mahadi, Tarig Ballal, Muhammad Moinuddin +2
This paper is concerned with optimizing the global minimum-variance portfolio's (GMVP) weights in high-dimensional settings where both observation and population dimensions grow at…
Constrained Wrapped Least Squares: A Tool for High Accuracy GNSS Attitude Determination
Xing Liu, Tarig Ballal, Hui Chen +1
Attitude determination is a popular application of Global Navigation Satellite Systems (GNSS). Many methods have been developed to solve the attitude determination problem with dif…
A Tutorial on Terahertz-Band Localization for 6G Communication Systems
Hui Chen, Hadi Sarieddeen, Tarig Ballal +3
Terahertz (THz) communications are celebrated as key enablers for converged localization and sensing in future sixth-generation (6G) wireless communication systems and beyond. Inst…
Details Preserving Deep Collaborative Filtering-Based Method for Image Denoising
Basit O. Alawode, Mudassir Masood, Tarig Ballal +1
In spite of the improvements achieved by the several denoising algorithms over the years, many of them still fail at preserving the fine details of the image after denoising. This…
Collaborative Filtering-Based Method for Low-Resolution and Details Preserving Image Denoising
Basit O. Alawode, Mudassir Masood, Tarig Ballal +1
Over the years, progressive improvements in denoising performance have been achieved by several image denoising algorithms that have been proposed. Despite this, many of these stat…
DOA Estimation with Non-Uniform Linear Arrays: A Phase-Difference Projection Approach
Hui Chen, Tarig Ballal, Tareq Y. Al-Naffouri
Phase wrapping is a major problem in direction-of-arrival (DOA) estimation using phase-difference observations. For a sensor pair with an inter-sensor spacing greater than half of…
A Derivation of Identifiable Condition for Non-Uniform Linear Array DOA Estimation
Hui Chen, Tarig Ballal, Tareq Y. Al-Naffouri
Phase ambiguity happens in uniform linear arrays (ULAs) when the sensor distance is greater than . This problem in direction of arrival (DOA) estimation and can be solved by d…
A Doubly Regularized Linear Discriminant Analysis Classifier with Automatic Parameter Selection
Alam Zaib, Tarig Ballal, Shahid Khattak +1
Linear discriminant analysis (LDA) based classifiers tend to falter in many practical settings where the training data size is smaller than, or comparable to, the number of feature…
SNR Estimation in Linear Systems with Gaussian Matrices
Mohamed A. Suliman, Ayed M. Alrashdi, Tarig Ballal +1
This paper proposes a highly accurate algorithm to estimate the signal-to-noise ratio (SNR) for a linear system from a single realization of the received signal. We assume that the…
Robust Regularized Least-Squares Beamforming Approach to Signal Estimation
Mohamed Suliman, Tarig Ballal, Tareq Y. Al-Naffouri
In this paper, we address the problem of robust adaptive beamforming of signals received by a linear array. The challenge associated with the beamforming problem is twofold. Firstl…
Perturbation-Based Regularization for Signal Estimation in Linear Discrete Ill-posed Problems
Mohamed Suliman, Tarig Ballal, Tareq Y. Al-Naffouri
Estimating the values of unknown parameters from corrupted measured data faces a lot of challenges in ill-posed problems. In such problems, many fundamental estimation methods fail…
Image Denoising Via Collaborative Support-Agnostic Recovery
Muzammil Behzad, Mudassir Masood, Tarig Ballal +2
In this paper, we propose a novel image denoising algorithm using collaborative support-agnostic sparse reconstruction. An observed image is first divided into patches. Similarly s…
Supplementary Appendix for: Constrained Perturbation Regularization Approach for Signal Estimation Using Random Matrix Theory
Mohamed Suliman, Tarig Ballal, Abla Kammoun +1
In this supplementary appendix we provide proofs and additional extensive simulations that complement the analysis of the main paper (constrained perturbation regularization approa…