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๐Ÿ” ulla griffiths ๐Ÿ“‚ Engineering
Showing 115 results for "ulla griffiths" in Engineering
Engineering Preprint PDF DOI

Rank-Aware Link Adaptation for XR Tethering Groups with Realistic Tethering Link: A Multi-Offset OLLA Framework

Muhammad Ahsen, Boyan Yanakiev, Claudio Rosa, Ramoni Adeogun ยท 2026

We investigate higher-rank transmissions for multi-connected Extended Reality (XR) devices enabled through tethering group (TGr), in which a nearby tethering User Equipment (UE) cooperates with an XR โ€ฆ

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Engineering Preprint PDF DOI

DUSG-Tomo-Net: A Deep Unfolded Neural Network for Super-Resolving Gridless Spaceborne SAR Tomography via Learned Toeplitz-Structured Covariance Representation

Kun Qian, Zhuge Xia, Qian Ma, Qi Zhang, Weijian Liu, Xiufeng He ยท 2026

Synthetic aperture radar tomography (TomoSAR) enables 3-D imaging by exploiting multibaseline acquisitions and has become an important tool for urban mapping. To achieve super-resolution inversion, spโ€ฆ

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Engineering Preprint PDF DOI

Phase-Field Peridynamics

Kai Partmann, Christian Wieners, Michael Ortiz, Kerstin Weinberg ยท 2026

Peridynamics formulates the balance of linear momentum as an integro-differential equation, making it naturally suited for fracture modeling without special treatment of discontinuities. The bond-assoโ€ฆ

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Engineering Preprint PDF DOI

Joint Range-Angle Estimation in Near-Field ISAC System using Uniform Circular Array

Lorenzo Zaniboni, Mark F. Flanagan ยท 2026

This paper studies joint range-angle estimation and communication in the NF ISAC systems, where the BS serves a single UE whose position is simultaneously estimated via monostatic sensing. Unlike the โ€ฆ

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Engineering Preprint PDF DOI

3D User Localization for Planar Arrays in LoS Near- and Far-Fields via Summed Phase Differences

Sergey Isaev, Nikola Zlatanov ยท 2026

This paper presents a phase-difference-based scheme for three-dimensional (3D) line-of-sight (LoS) user localization using a uniform planar array (UPA), applicable to both near-field and far-field regโ€ฆ

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Engineering Preprint PDF DOI

Terahertz Beam Squint Mitigation via Six-Dimensional Movable Antennas

Yike Xie, Weidong Mei, Dong Wang, Yingqi Wen, Zhi Chen, Jun Fang, Wei Guo, Boyu Ning ยท 2026

Analog beamforming holds great potential for future terahertz (THz) communications due to its ability to generate high-gain directional beams with low-cost phase shifters. However, conventional analogโ€ฆ

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Engineering Preprint PDF DOI

Near-Field Channel Estimation for mmWave/THz Communications with Extremely Large-Scale UPAs

Yiming Chen, Hongwei Wang, Lingxiang Li, Zhi Chen ยท 2026

Extremely large antenna arrays (ELAAs) are widely adopted in mmWave/THz communications to compensate for the severe path loss, wherein the channel estimation remains a significant challenge since the โ€ฆ

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Engineering Preprint PDF DOI

Airy Beam Engineering in Near-field Communications: A Tractable Closed-Form Analysis in the Terahertz Band

Wenqi Zhao, Chong Han, Emil Bjornson ยท 2026

Terahertz (THz) communication can offer terabit-per-second rates in future wireless systems, thanks to the ultra-wide bandwidths, but require large antenna arrays. As antenna apertures expand and we eโ€ฆ

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Engineering Preprint PDF DOI

Array Geometry-Centric Axial Sidelobe Interference Analysis for Near-Field Multi-User MIMO

Ahmed Hussain, Asmaa Abdallah, Abdulkadir Celik, Ahmed M. Eltawil ยท 2026

With the deployment of large antenna arrays at high-frequency bands, future wireless communication systems are likely to operate in the radiative near-field (NF). Unlike far-field beam steering, NF beโ€ฆ

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Engineering Preprint PDF DOI

Spatial Degrees of Freedom in Near Field MIMO: Experimental Validation of Beamspace Perspective

Ahmed Hussain, Asmaa Abdallah, Ahmed Nasser, Abdulkadir Celik, Ahmed M. Eltawil ยท 2026

Conventional far-field multiple-input multiple-output (MIMO) channels are limited to a single spatial degree of freedom (DoF) under a line-of-sight (LoS) condition. In contrast, the radiative near fieโ€ฆ

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Engineering Preprint PDF DOI

Analyzing URA Geometry for Enhanced Near-Field Beamfocusing and Spatial Degrees of Freedom

Ahmed Hussain, Asmaa Abdallah, Abdulkadir Celik, Emil Bjornson, Ahmed M. Eltawil ยท 2026

With the deployment of large antenna arrays at high-frequency bands, future wireless communication systems are likely to operate in the radiative near-field. Unlike far-field beam steering, near-fieldโ€ฆ

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Engineering Preprint PDF DOI

Cross-Pilot Superposition for Fractional Parameter Estimation in DoA-Aided OTFS Receivers

Mauro Marchese, Pietro Savazzi ยท 2026

In this letter, a novel superimposed pilot scheme is proposed for channel estimation in multi-antenna orthogonal time frequency space (OTFS) receivers. Under the assumption of a large uniform linear aโ€ฆ

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Engineering Preprint PDF DOI

TIC-VLA: A Think-in-Control Vision-Language-Action Model for Robot Navigation in Dynamic Environments

Zhiyu Huang, Yun Zhang, Johnson Liu, Rui Song, Chen Tang, Jiaqi Ma ยท 2026

Robots in dynamic, human-centric environments must follow language instructions while maintaining real-time reactive control. Vision-language-action (VLA) models offer a promising framework, but they โ€ฆ

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Engineering Preprint PDF DOI

Task-Based Adaptive Transmit Beamforming for Efficient Ultrasound Quantification

Oisin Nolan, Wessel L. van Nierop, Louis D. van Harten, Tristan S.W. Stevens, Ruud J.G. van Sloun ยท 2026

Wireless and wearable ultrasound devices promise to enable continuous ultrasound monitoring, but power consumption and data throughput remain critical challenges. Reducing the number of transmit eventโ€ฆ

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Engineering Preprint PDF DOI

Misspecified Crame-Rao Bound for AoA Estimation at a ULA under a Spoofing Attack

Sotiris Skaperas, Arsenia Chorti ยท 2025

A framework is presented for analyzing the impact of active attacks to location-based physical layer authentication (PLA) using the machinery of misspecified Cram\'er--Rao bound (MCRB). In this work, โ€ฆ

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Engineering Preprint PDF DOI

XR Capacity Enhancement through Multi-Connected XR Tethering Groups

Muhammad Ahsen, Boyan Yanakiev, Claudio Rosa, Ramoni Adeogun ยท 2025

Extended Reality (XR) applications have limited capacity in 5th generation-advanced (5G-A) cellular networks due to high throughput requirements coupled with strict latency and high reliability constrโ€ฆ

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Engineering Preprint PDF DOI

Cost-Effective XL-MIMO Communication with Cylinder Directly-Connected Antenna Array

Xuancheng Zhu, Zhiwen Zhou, Zhenjun Dong, Yong Zeng ยท 2025

Extremely large-scale multi-input multi-output (XL-MIMO) is a promising technology for the sixth generation (6G) wireless networks, thanks to its superior spatial resolution and beamforming gains. In โ€ฆ

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Engineering Preprint PDF DOI

Commanding Humanoid by Free-form Language: A Large Language Action Model with Unified Motion Vocabulary

Zhirui Liu, Kaiyang Ji, Ke Yang, Jingyi Yu, Ye Shi, Jingya Wang ยท 2025

Enabling humanoid robots to follow free-form language commands is critical for seamless human-robot interaction, collaborative task execution, and general-purpose embodied intelligence. While recent aโ€ฆ

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Engineering Preprint PDF DOI

Performance Bounds for Near-Field Velocity Estimation with Modular Linear Array

Khalid A. Alshumayri, Mudassir Masood, Ali. A. Nasir ยท 2025

Velocity estimation is a cornerstone of the recently introduced near-field predictive beamforming. This paper derives the Cramer-Rao bounds (CRBs) for joint radial and transverse velocity estimation wโ€ฆ

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Engineering Preprint PDF DOI

TRACE: Textual Reasoning for Affordance Coordinate Extraction

Sangyun Park, Jin Kim, Yuchen Cui, Matthew S. Brown ยท 2025

Vision-Language Models (VLMs) struggle to translate high-level instructions into the precise spatial affordances required for robotic manipulation. While visual Chain-of-Thought (CoT) methods exist, tโ€ฆ

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