pwc-archive/papers-with-abstracts huggingface dataset:
Grouped Target Tracking and Seamless People Counting with a 24 GHz MIMO FMCW
Authors: Dingyang Wang, Sen Yuan, Alexander Yarovoy, Francesco Fioranelli
Date: 2025-04-07 00:00:00

The problem of radar-based tracking of groups of people moving together and counting their numbers in indoor environments is considered here. A novel processing pipeline to track groups of people moving together and count their numbers is proposed and validated. The pipeline is specifically designed to deal with frequent changes of direction and stop & go movements typical of indoor activities. The proposed approach combines a tracker with a classifier to count the number of grouped people; this uses both spatial features extracted from range-azimuth maps, and Doppler frequency features extracted with wavelet decomposition. Thus, the pipeline outputs over time both the location and number of people present. The proposed approach is verified with experimental data collected with a 24 GHz Frequency Modulated Continuous Wave (FMCW) radar. It is shown that the proposed method achieves 95.59% accuracy in counting the number of people, and a tracking metric OSPA of 0.338. Furthermore, the performance is analyzed as a function of different relevant variables such as feature combinations and scenarios.
Advanced Codebook Design for SCMA-aided NTNs With Randomly Distributed Users
Authors: Tianyang Hu, Qu Luo, Lixia Xiao, Jiaxi Zhou, Pei Xiao, Tao Jiang
Date: 2025-04-07 00:00:00
Tasks: Diversity, Fairness

In this letter, a novel class of sparse codebooks is proposed for sparse code multiple access (SCMA) aided non-terrestrial networks (NTN) with randomly distributed users characterized by Rician fading channels. Specifically, we first exploit the upper bound of bit error probability (BEP) of an SCMA-aided NTN with large-scale fading of different users under Rician fading channels. Then, the codebook is designed by employing pulse-amplitude modulation constellation, user-specific rotation and power factors. To further reduce the optimization complexity while maintaining the power diversity of different users, an orthogonal layer-assisted joint layer and power assignment strategy is proposed. Finally, unlike existing SCMA codebook designs that treat all users as one super-user, we propose to minimize the BEP of the worst user to ensure user fairness. The simulation results show that the proposed scheme is capable of providing a substantial performance gain over conventional codebooks.
Parallelization is All System Identification Needs: End-to-end Vibration Diagnostics on a multi-core RISC-V edge device
Authors: Amirhossein Kiamarzi, Amirhossein Moallemi, Federica Zonzini, Davide Brunelli, Davide Rossi, Giuseppe Tagliavini
Date: 2025-04-07 00:00:00
Tasks: All

The early detection of structural malfunctions requires the installation of real-time monitoring systems ensuring continuous access to the damage-sensitive information; nevertheless, it can generate bottlenecks in terms of bandwidth and storage. Deploying data reduction techniques at the edge is recognized as a proficient solution to reduce the system's network traffic. However, the most effective solutions currently employed for the purpose are based on memory and power-hungry algorithms, making their embedding on resource-constrained devices very challenging; this is the case of vibration data reduction based on System Identification models. This paper presents PARSY-VDD, a fully optimized PArallel end-to-end software framework based on SYstem identification for Vibration-based Damage Detection, as a suitable solution to perform damage detection at the edge in a time and energy-efficient manner, avoiding streaming raw data to the cloud. We evaluate the damage detection capabilities of PARSY-VDD with two benchmarks: a bridge and a wind turbine blade, showcasing the robustness of the end-to-end approach. Then, we deploy PARSY-VDD on both commercial single-core and a specific multi-core edge device. We introduce an architecture-agnostic algorithmic optimization for SysId, improving the execution by 90x and reducing the consumption by 85x compared with the state-of-the-art SysId implementation on GAP9. Results show that by utilizing the unique parallel computing capabilities of GAP9, the execution time is 751{\mu}s with the high-performance multi-core solution operating at 370MHz and 0.8V, while the energy consumption is 37{\mu}J with the low-power solution operating at 240MHz and 0.65V. Compared with other single-core implementations based on STM32 microcontrollers, the GAP9 high-performance configuration is 76x faster, while the low-power configuration is 360x more energy efficient.
Attentional Graph Meta-Learning for Indoor Localization Using Extremely Sparse Fingerprints
Authors: Wenzhong Yan, Feng Yin, Jun Gao, Ao Wang, Yang Tian, Ruizhi Chen
Date: 2025-04-07 00:00:00
Tasks: Data Augmentation, Graph Neural Network, Indoor Localization, Meta-Learning

Fingerprint-based indoor localization is often labor-intensive due to the need for dense grids and repeated measurements across time and space. Maintaining high localization accuracy with extremely sparse fingerprints remains a persistent challenge. Existing benchmark methods primarily rely on the measured fingerprints, while neglecting valuable spatial and environmental characteristics. In this paper, we propose a systematic integration of an Attentional Graph Neural Network (AGNN) model, capable of learning spatial adjacency relationships and aggregating information from neighboring fingerprints, and a meta-learning framework that utilizes datasets with similar environmental characteristics to enhance model training. To minimize the labor required for fingerprint collection, we introduce two novel data augmentation strategies: 1) unlabeled fingerprint augmentation using moving platforms, which enables the semi-supervised AGNN model to incorporate information from unlabeled fingerprints, and 2) synthetic labeled fingerprint augmentation through environmental digital twins, which enhances the meta-learning framework through a practical distribution alignment, which can minimize the feature discrepancy between synthetic and real-world fingerprints effectively. By integrating these novel modules, we propose the Attentional Graph Meta-Learning (AGML) model. This novel model combines the strengths of the AGNN model and the meta-learning framework to address the challenges posed by extremely sparse fingerprints. To validate our approach, we collected multiple datasets from both consumer-grade WiFi devices and professional equipment across diverse environments. Extensive experiments conducted on both synthetic and real-world datasets demonstrate that the AGML model-based localization method consistently outperforms all baseline methods using sparse fingerprints across all evaluated metrics.
Cross-Frame OTFS Parameter Estimation Based On Chinese Remainder Theorem
Authors: Zhenyu Zhang, Qianli Wang, Gang Liu, Feifei Gao, Pingzhi Fan
Date: 2025-04-07 00:00:00
Tasks: ISAC, parameter estimation

Orthogonal time-frequency space (OTFS) is a potential waveform for integrated sensing and communications (ISAC) systems because it can manage communication and sensing metrics in one unified domain, and has better performance in high mobility scenarios. In practice, a target might come from far distance or with ultra-high speed. However, the max unambiguous range and max tolerable velocity of OTFS-ISAC system is limited by the unambiguous round-trip delay and Doppler shift, which are related to OTFS frame, i.e., time slots and subcarrier spacing, respectively. To enlarge the sensing range, a novel OTFS cross-frame ranging and velocity estimation model as well as its corresponding method based on the Chinese remainder theorem (CRT) are proposed in this paper. By designing co-prime numbers of subcarriers and time slots in different subframes, the difference in the responses of the subframes for a target can be used to estimate the distance and velocity of an out-of-range target. Several frame structures are further designed for specific sensing scenarios, such as target with ultra-high speed or at far distance. Simulation results show that the proposed method can achieve significantly better performance in NMSE compared with the classic sensing methods under the condition of same time and frequency resources.
Addressing the Curse of Scenario and Task Generalization in AI-6G: A Multi-Modal Paradigm
Authors: Tianyu Jiao, Zhuoran Xiao, Yin Xu, Chenhui Ye, Yihang Huang, Zhiyong Chen, Liyu Cai, Jiang Chang, Dazhi He, Yunfeng Guan, Guangyi Liu, Wenjun Zhang
Date: 2025-04-07 00:00:00

Existing works on machine learning (ML)-empowered wireless communication primarily focus on monolithic scenarios and single tasks. However, with the blooming growth of communication task classes coupled with various task requirements in future 6G systems, this working pattern is obviously unsustainable. Therefore, identifying a groundbreaking paradigm that enables a universal model to solve multiple tasks in the physical layer within diverse scenarios is crucial for future system evolution. This paper aims to fundamentally address the curse of ML model generalization across diverse scenarios and tasks by unleashing multi-modal feature integration capabilities in future systems. Given the universality of electromagnetic propagation theory, the communication process is determined by the scattering environment, which can be more comprehensively characterized by cross-modal perception, thus providing sufficient information for all communication tasks across varied environments. This fact motivates us to propose a transformative two-stage multi-modal pre-training and downstream task adaptation paradigm...
Localization and Tracking for Cooperative Users in Multi-RIS-assisted Systems: Theoretical Analysis and Principles of Interpretations
Authors: Peng Gao, Lixiang Lian, Yuan Shen
Date: 2025-04-07 00:00:00

Localization and tracking (LocTrack) are fundamental enablers for a wide range of emerging applications. Reconfigurable intelligent surfaces (RISs) have emerged as key components for enhancing the LocTrack performance. This paper investigates a multi-RIS-assisted multi-user (MRMU) LocTrack system, where multiple RISs collaboratively reflect the position-bearing signals for information fusion at the base station, leveraging spatial-temporal correlations in user positions. While studies have shown these correlations improve localization accuracy, their trade-offs with system complexity remain unclear. To address this gap, we characterize the effectiveness of spatial-temporal correlation priors (STPs) utilization in MRMU LocTrack systems using a metric, termed efficiency of correlation (EoC). To further elucidate correlation propagation and RIS interactions, we provide a "correlation information routing" interpretation of EoC through random walk theory. EoC provides a principled performance evaluation metric, that enables system designers to balance localization accuracy enhancement against the increased complexity. Additionally, we investigate the error propagation phenomenon, analyzing its convergence and asymptotic behavior in MRMU LocTrack systems. Finally, we validate the theoretical results through extensive numerical simulations.
Classification of ADHD and Healthy Children Using EEG Based Multi-Band Spatial Features Enhancement
Authors: Md Bayazid Hossain, Md Anwarul Islam Himel, Md Abdur Rahim, Shabbir Mahmood, Abu Saleh Musa Miah, Jungpil Shin
Date: 2025-04-07 00:00:00
Tasks: EEG, Electroencephalogram (EEG)

Attention Deficit Hyperactivity Disorder (ADHD) is a common neurodevelopmental disorder in children, characterized by difficulties in attention, hyperactivity, and impulsivity. Early and accurate diagnosis of ADHD is critical for effective intervention and management. Electroencephalogram (EEG) signals have emerged as a non-invasive and efficient tool for ADHD detection due to their high temporal resolution and ability to capture neural dynamics. In this study, we propose a method for classifying ADHD and healthy children using EEG data from the benchmark dataset. There were 61 children with ADHD and 60 healthy children, both boys and girls, aged 7 to 12. The EEG signals, recorded from 19 channels, were processed to extract Power Spectral Density (PSD) and Spectral Entropy (SE) features across five frequency bands, resulting in a comprehensive 190-dimensional feature set. To evaluate the classification performance, a Support Vector Machine (SVM) with the RBF kernel demonstrated the best performance with a mean cross-validation accuracy of 99.2\% and a standard deviation of 0.0079, indicating high robustness and precision. These results highlight the potential of spatial features in conjunction with machine learning for accurately classifying ADHD using EEG data. This work contributes to developing non-invasive, data-driven tools for early diagnosis and assessment of ADHD in children.
Turbocharging Fluid Antenna Multiple Access
Authors: Noor Waqar, Kai-Kit Wong, Chan-Byoung Chae, Ross Murch
Date: 2025-04-06 00:00:00
Tasks: Denoising

We revisit the massive connectivity challenge by considering the case where no CSI is available at the BS and no precoding is used. In this situation, inter-user interference (IUI) mitigation can only be performed at the user terminal (UT) side. Leveraging the position flexibility of fluid antenna system (FAS), we adopt a fluid antenna multiple access (FAMA) approach that exploits the interference signal fluctuation in the spatial domain. Specifically, we assume that we have N spatially correlated received signals per symbol duration from FAS. Our main approach uses a simple heuristic port shortlisting method that identifies promising ports to obtain favourable received signals that can be combined via maximum ratio combining (MRC) to form the received output signal for final detection. On top of this, a pre-trained deep joint source channel coding (JSCC) scheme is employed, which together with a diffusion-based denoising model (MixDDPM) at the UT side, can improve the IUI immunity. We refer to the proposed scheme as turbo FAMA. Simulation results show that with a physical FAS size of 20 wavelengths at each UT transmitting quaternary phase shift keying (QPSK) symbols, fast FAMA can support 50 users while turbo FAMA can handle up to 200 users if the required symbol error rate (SER) is 10 2. If a higher error tolerance is acceptable, say SER at 01, turbo FAMA can even serve up to 1000 users but fast FAMA is only able to handle 160 users, all remarkably achieved without CSI at the BS.
Model-Based Deep Learning Tuning of Reconfigurable Intelligent Surface for OFDM Radar Interference Mitigation
Authors: Ali Parchekani, Milad Johnny, Shahrokh Valaee
Date: 2025-04-06 00:00:00

This paper presents a deep learning-based framework for enhancing radar systems in the presence of interference, leveraging Reconfigurable Intelligent Surfaces (RIS). The proposed technique uses a modified MUSIC algorithm to estimate the angles of the target and interference. The core of the method is a deep learning model that optimizes the RIS configuration to reduce the impact of interference while maintaining accurate angle estimates. The model consists of a multi-layer perceptron (MLP) that takes estimated angles as inputs and outputs the configuration of the RIS. A specially designed loss function ensures that the interference is properly suppressed and the target remains detectable. To further enhance performance, a convolution technique is introduced to create a notch at the interference angle, ensuring better separation between the target and interference. Additionally, the method is extended to work over multiple subcarriers, improving robustness and performance in practical scenarios. Simulation results show that the technique enhances the signal-to-interference-plus-noise ratio (SINR) and provides accurate localization estimates, demonstrating its potential for radar systems in complex environments.
Cramer-Rao Bounds for Laplacian Matrix Estimation
Authors: Morad Halihal, Tirza Routtenberg, H. Vincent Poor
Date: 2025-04-06 00:00:00

In this paper, we analyze the performance of the estimation of Laplacian matrices under general observation models. Laplacian matrix estimation involves structural constraints, including symmetry and null-space properties, along with matrix sparsity. By exploiting a linear reparametrization that enforces the structural constraints, we derive closed-form matrix expressions for the Cramer-Rao Bound (CRB) specifically tailored to Laplacian matrix estimation. We further extend the derivation to the sparsity-constrained case, introducing two oracle CRBs that incorporate prior information of the support set, i.e. the locations of the nonzero entries in the Laplacian matrix. We examine the properties and order relations between the bounds, and provide the associated Slepian-Bangs formula for the Gaussian case. We demonstrate the use of the new CRBs in three representative applications: (i) topology identification in power systems, (ii) graph filter identification in diffused models, and (iii) precision matrix estimation in Gaussian Markov random fields under Laplacian constraints. The CRBs are evaluated and compared with the mean-squared-errors (MSEs) of the constrained maximum likelihood estimator (CMLE), which integrates both equality and inequality constraints along with sparsity constraints, and of the oracle CMLE, which knows the locations of the nonzero entries of the Laplacian matrix. We perform this analysis for the applications of power system topology identification and graphical LASSO, and demonstrate that the MSEs of the estimators converge to the CRB and oracle CRB, given a sufficient number of measurements.
ANN-Driven Adaptive Power Allocation for OWC
Authors: Walter Zibusiso Ncube, Ahmad Adnan Qidan, Taisir El-Gorashi, Jaafar M. H. Elmirghani
Date: 2025-04-06 00:00:00

Vertical-cavity surface-emitting lasers (VCSELs) have gained popularity in Optical Wireless Communication (OWC) due to their high bandwidth and directional beam compared to Light-emitting diodes (LEDs). In this work, we explore the deployment of VCSELs as Access Points (APs) in an indoor environment with time-varying user distributions and traffic demands. To enhance performance, a merged access point (MAP) topology is introduced to extend the serving area of each cell using Zero Forcing (ZF) for interference management. A power allocation optimisation problem is formulated aimed at maximising the sum rate of the dynamic network. Deterministic approaches can solve the formulated problem but are impractical for real-time scenarios. In this work, we propose an Artificial Neural Network (ANN) for adaptive power allocation with reduced computational complexity. Our results show that the designed ANN learns and effectively provides instantaneous solutions in dynamic scenarios, resulting in improved performance in terms of sum rate compared to a baseline uniform power allocation scheme.
Opportunistic Beamforming and Dynamic Scheduling for Multi-User MIMO-ISAC Systems
Authors: Tharaka Perera, Saman Atapattu, Chathuranga Weeraddana, Jamie Evans
Date: 2025-04-06 00:00:00
Tasks: ISAC, Scheduling

This research presents a novel framework integrating Flexible-Duplex (FlexD) and Integrated Sensing and Communications (ISAC) technologies to address the challenges of spectrum efficiency and resource optimization in next-generation wireless networks. We develop a unified system model for a dual-functional radar-communication base station with multiple-input multiple-output capabilities, enabling dynamic uplink and downlink channel allocation. The framework maximizes network throughput while maintaining radar sensing performance, subject to signal-to-clutter-plus-noise ratio (SCNR) requirements and power constraints. Given the non-convex and combinatorial nature of the resulting optimization problem, we propose an iterative algorithm that converges to a locally optimal solution. Extensive simulations demonstrate the superiority of the proposed FlexD-ISAC framework compared to conventional half-duplex networks. Additionally, sensitivity analyses reveal the impact of SCNR requirements and power constraints on system performance, providing valuable insights for practical implementation. This work establishes a foundation for future research in dynamic, resource-efficient wireless systems that simultaneously support sensing and communication capabilities.
DSSR-Net for Super-Resolution Radar Range Profiles
Authors: Ziwen Wang, JianPing Wang, Pucheng Li, Zegang Ding
Date: 2025-04-06 00:00:00
Tasks: Super-Resolution

High-resolution radar range profile (RRP) is crucial for accurate target recognition and scene perception. To get a high-resolution RRP, many methods have been developed, such as multiple signal classification (MUSIC), orthogonal matching pursuit (OMP), and a few deep learning-based approaches. Although they break through the Rayleigh resolution limit determined by radar signal bandwidth, these methods either get limited super-resolution capability or work well just in high signal to noise ratio (SNR) scenarios. To overcome these limitations, in this paper, an interpretable neural network for super-resolution RRP (DSSR-Net) is proposed by integrating the advantages of both model-guided and data-driven models. Specifically, DSSR-Net is designed based on a sparse representation model with dimension scaling, and then trained on a training dataset. Through dimension scaling, DSSR-Net lifts the radar signal into high-dimensional space to extract subtle features of closely spaced objects and suppress the noise of the high-dimensional features. It improves the super-resolving power of closely spaced objects and lowers the SNR requirement of radar signals compared to existing methods. The superiority of the proposed algorithm for super-resolution RRP reconstruction is verified via experiments with both synthetic and measured data.
TFDWT: Fast Discrete Wavelet Transform TensorFlow Layers
Authors: Kishore K. Tarafdar, Vikram M. Gadre
Date: 2025-04-05 00:00:00

TFDWT is an open-source Python library that allows the construction of TensorFlow Layers for Fast Discrete Wavelet Transform (DWT) and Inverse Discrete Wavelet Transform (IDWT) in end-to-end backpropagation learning networks. By definition, a multiresolution signal representation using a multi-rate discrete wavelet system creates enriched joint natural-frequency representations. These layers facilitate the construction of multilevel DWT filter banks and Wavelet Packet Transform (WPT) filter banks for a spatial-frequency representation of the inputs and features in shallow or deep networks. The discrete wavelet system partitions the frequency plane into subbands using orthogonal dilated and translated lowpass scaling and highpass wavelet function. The realization of a fast discrete wavelet system is a two-band perfect reconstruction multi-rate filter bank with FIR filters corresponding to the impulse responses of the scaling and wavelet function with downsampling and upsampling operations. A filter bank for a higher dimensional input is a seamless extension by successive separable circular convolutions across each independent axis. The command `pip install TFDWT' installs the latest version of the package.