NPJ wireless technology最新文献

Hybrid ray-tracing-QuaDRiGa/FDTD method for realistic 28 GHz exposure with 6G CF-MaMIMO in 3D outdoor environments. 混合光线跟踪- quadriga /FDTD方法在3D室外环境中使用6G CF-MaMIMO实现28 GHz真实曝光。

NPJ wireless technology Pub Date : 2026-01-01 Epub Date: 2026-04-02 DOI: 10.1038/s44459-026-00031-4

Robin Wydaeghe, Sergei Shikhantsov, Günter Vermeeren, Luc Martens, Emmeric Tanghe, Wout Joseph

{"title":"Hybrid ray-tracing-QuaDRiGa/FDTD method for realistic 28 GHz exposure with 6G CF-MaMIMO in 3D outdoor environments.","authors":"Robin Wydaeghe, Sergei Shikhantsov, Günter Vermeeren, Luc Martens, Emmeric Tanghe, Wout Joseph","doi":"10.1038/s44459-026-00031-4","DOIUrl":"10.1038/s44459-026-00031-4","url":null,"abstract":"Amid worry for 5G and 6G, the layman's question arises: \"How much exposure do I realistically experience when I walk down the street?\" Focusing on mmWave radio-frequency electromagnetic field exposure with Distributed Massive Multiple-Input Multiple-Output (DMaMIMO) technology, a new state-of-the-art (SOTA) numerical method is proposed to enable accurate exposure assessment almost anywhere on Earth. Google Earth 3D photorealistic tiles provide high-level-of-detail and high-coverage photogrammetry. We semantically classify the meshes with an SOTA deep learning model. The path of a pedestrian is first ray-traced at 28 GHz with either 6G DMaMIMO or realistically deployed 5G antenna systems as the transmitter. The large-scale fading parameters are extracted and form the input for the QuaDRiGa tool, which finely models the small-scale fading features of the channel along the full path with an omnidirectional User Equipment (UE) as receiver. The resulting channel is used in a hybridization procedure with a Huygens' box that models the Electromagnetic Fields (EMFs) around the UE. The surface-absorbed power density (S ab) exposure metric is computed along the path using FDTD simulations of a realistic anatomical phantom. A case study in Helsinki finds that the cell-free MaMIMO free-space exposure range is 20 dB more uniform than collocated MaMIMO. A case study in New York City finds that users experience, on average, 20 dB higher values in exposure compared to non-users. The small-scale fading hotspot phenomenon in realistic environments is studied in detail, showing on average a 12 dB electric field increase w.r.t. the background and a specific shape with up to 3 sidelobes, which is characterized quantitatively. The S ab is less than 1% of the ICNIRP guidelines during all simulations at realistic Tx powers.","PeriodicalId":521122,"journal":{"name":"NPJ wireless technology","volume":"2 1","pages":"13"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13046467/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147625463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Low-latency jamming mitigation in SWaP-constrained GNSS analog CRPAs via hierarchical dithered null steering. 基于层次抖动零转向的swap约束GNSS模拟crpa低延迟干扰缓解。

NPJ wireless technology Pub Date : 2026-01-01 Epub Date: 2026-07-03 DOI: 10.1038/s44459-026-00049-8

Mazen Elaraby, Ali Massoud, Mai Hassan, Haidy Elghamrawy, Aboelmagd Noureldin

{"title":"Low-latency jamming mitigation in SWaP-constrained GNSS analog CRPAs via hierarchical dithered null steering.","authors":"Mazen Elaraby, Ali Massoud, Mai Hassan, Haidy Elghamrawy, Aboelmagd Noureldin","doi":"10.1038/s44459-026-00049-8","DOIUrl":"10.1038/s44459-026-00049-8","url":null,"abstract":"Global Navigation Satellite Systems (GNSS) underpin critical functions in modern society, from autonomous ground vehicles and unmanned aerial vehicles to civil infrastructure and defense operations. Yet, the extreme weakness of GNSS signals at the Earth's surface makes them acutely vulnerable to intentional jamming, threatening the reliability of safety- and mission-critical applications. Controlled Reception Pattern Antennas (CRPAs) with analog beamforming offer a compact, power-efficient defense against jammers, but mitigation remains difficult: the literature on analog CRPAs is sparse, and existing approaches often rely on naïve grid searches that are too slow for deployment and prone to failure in practice. In this paper, we introduce a hierarchical search framework tailored to the constraints of analog CRPAs. Our method combines binary refinement with lightweight dithering to overcome fundamental pitfalls of grid-based null steering, where mismatches between null width and grid resolution obscure the jammer's direction. By exploiting suppression contrast as a guiding signal, the algorithm identifies and resolves ambiguous cases without resorting to exhaustive probing. Simulations with a four-element analog CRPA demonstrate mean jammer suppression levels of nearly 50 dB while reducing measurement complexity by approximately 96% on average compared to exhaustive search (up to 98% in the best case), making low-latency operation feasible on size-, weight-, and power (SWaP)-constrained GNSS receivers.","PeriodicalId":521122,"journal":{"name":"NPJ wireless technology","volume":"2 1","pages":"43"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13331733/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148392961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Securing the sensing functionality in ISAC: KLD-based ambiguity function shaping. 确保ISAC中的感知功能：基于kld的模糊函数塑造。

NPJ wireless technology Pub Date : 2026-01-01 Epub Date: 2026-10-01 DOI: 10.1038/s44459-026-00089-0

Borui Du, Kawon Han, Christos Masouros

{"title":"Securing the sensing functionality in ISAC: KLD-based ambiguity function shaping.","authors":"Borui Du, Kawon Han, Christos Masouros","doi":"10.1038/s44459-026-00089-0","DOIUrl":"https://doi.org/10.1038/s44459-026-00089-0","url":null,"abstract":"Integrated sensing and communication (ISAC) systems introduce a sensing-privacy vulnerability because unauthorized sensing eavesdroppers (Eve) may exploit ISAC signals for independent passive sensing. This work addresses sensing-security for orthogonal frequency-division multiplexing (OFDM)- and orthogonal time frequency space (OTFS)-based ISAC waveforms from a target-detection perspective. We develop system models for the base station (BS), user equipment, and Eve, and define a Kullback-Leibler divergence-based detection metric that accounts for mainlobe, sidelobe, and noise components in ambiguity-function and range-Doppler maps. Building on this analysis, we formulate a sensing-secure signaling design problem that tunes a perturbation matrix to jointly control signal amplitude and phase in the time-frequency domain and solve it via simulated annealing. Simulation results show that the proposed scheme substantially degrades Eve's detection probability-from 79.4% to 37.4% for OTFS and from 94.3% to 33.0% for OFDM-while incurring only a small loss in BS sensing performance. The proposed scheme also enables controllable sensing-security and communication trade-offs.","PeriodicalId":521122,"journal":{"name":"NPJ wireless technology","volume":"2 1","pages":"79"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13630560/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149123922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Indoor positioning with multi-domain CSI-based deep attention networks for MIMO wireless systems. 基于多域csi的MIMO无线系统室内深度注意网络定位。

NPJ wireless technology Pub Date : 2026-01-01 Epub Date: 2026-05-04 DOI: 10.1038/s44459-025-00021-y

Praneeth Susarla, Anirban Mukherjee, S S Krishna Chaitanya Bulusu, Pravallika Katragunta, Dinesh Babu Jayagopi, Miguel Bordallo López, Markku Juntti

{"title":"Indoor positioning with multi-domain CSI-based deep attention networks for MIMO wireless systems.","authors":"Praneeth Susarla, Anirban Mukherjee, S S Krishna Chaitanya Bulusu, Pravallika Katragunta, Dinesh Babu Jayagopi, Miguel Bordallo López, Markku Juntti","doi":"10.1038/s44459-025-00021-y","DOIUrl":"10.1038/s44459-025-00021-y","url":null,"abstract":"Accurate indoor positioning is vital for applications such as augmented reality and autonomous robotics. Channel state information (CSI)-based methods, particularly when combined with beamforming, massive multiple input multiple output (mMIMO) techniques, and artificial intelligence (AI) algorithms, offer enhanced indoor user equipment (UE) positioning accuracy and robustness in complex indoor environments. In this paper, we present an AI-driven CSI-based indoor positioning method for mMIMO systems, where channel impulse, channel frequency, and angular response domain features are extracted from the CSI data and combined to form both uni-domain and multi-domain feature sets. We introduce a deep attention network (DAN), an AI algorithm that leverages attention mechanisms to effectively integrate and process multi-domain CSI data, thereby enhancing UE positioning performance. We evaluate DAN using a publicly available mMIMO dataset and compare its performance against the baseline and multi-domain convolutional neural network (CNN) models. Our results show that multi-domain DAN outperforms CNN approaches in positioning accuracy, though at the cost of increased inference complexity-highlighting a trade-off between performance and computational overhead. These findings demonstrate the potential of attention mechanisms and multi-domain CSI features for accurate indoor UE positioning systems.","PeriodicalId":521122,"journal":{"name":"NPJ wireless technology","volume":"2 1","pages":"23"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13139032/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147849346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Overcoming the rate-power trade-off: multi-junction photovoltaic receivers for efficient near-infrared power and gigabit data transmission. 克服速率-功率权衡：多结光伏接收器的高效近红外功率和千兆数据传输。

NPJ wireless technology Pub Date : 2026-01-01 Epub Date: 2026-09-04 DOI: 10.1038/s44459-026-00079-2

Carmine Pellegrino, Richard Nacke, Behnaz Majlesein, Othman Younus, Isaac N O Osahon, Sina Babadi, Michael Schachtner, Gerald Siefer, David Lackner, Iman Tavakkolnia, Harald Haas, Henning Helmers

{"title":"Overcoming the rate-power trade-off: multi-junction photovoltaic receivers for efficient near-infrared power and gigabit data transmission.","authors":"Carmine Pellegrino, Richard Nacke, Behnaz Majlesein, Othman Younus, Isaac N O Osahon, Sina Babadi, Michael Schachtner, Gerald Siefer, David Lackner, Iman Tavakkolnia, Harald Haas, Henning Helmers","doi":"10.1038/s44459-026-00079-2","DOIUrl":"10.1038/s44459-026-00079-2","url":null,"abstract":"-Photonic power converters are promising receivers for simultaneous optical wireless information and power transfer systems. Fundamental trade-offs between generated power and data transmission speed, however, have constrained device performance. Here, we demonstrate that multi-junction architectures overcome these limitations, enabling concurrent optimization of both metrics. We introduce and validate a semi-empirical model describing static and dynamic responses of multi-junction devices. Our 4-junction InGaAsP photovoltaic receivers achieve 55.9% ± 2.0% power conversion efficiency at 27.1 W/cm² (1.45 µm) and 2.23 Gb/s using direct current-biased optical orthogonal frequency division multiplexing with adaptive bit and power loading. Over a 3‑m eye‑safe link at 1.53 µm, we simultaneously achieve 1.58 mW harvested power and 1.58 Gb/s. These results establish multi-junction photonic power converters as practical receivers and provide a solid framework for designing efficient optical wireless power transfer and communication systems.","PeriodicalId":521122,"journal":{"name":"NPJ wireless technology","volume":"2 1","pages":"65"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13545011/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148898881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Securing space domain awareness overview: decisions in the nick of time. 确保空间域感知概述：关键时刻的决策。

NPJ wireless technology Pub Date : 2026-01-01 Epub Date: 2026-04-02 DOI: 10.1038/s44459-025-00020-z

Nesrine Benchoubane, Gunes Karabulut Kurt

引用次数: 0

DRL-based power allocation in LiDAL-assisted RLNC-NOMA OWC systems. lidal辅助RLNC-NOMA OWC系统中基于drl的功率分配。

NPJ wireless technology Pub Date : 2026-01-01 Epub Date: 2026-08-04 DOI: 10.1038/s44459-026-00062-x

Ahmed A Hassan, Ahmad Adnan Qidan, Taisir Elgorashi, Jaafar Elmirghani

{"title":"DRL-based power allocation in LiDAL-assisted RLNC-NOMA OWC systems.","authors":"Ahmed A Hassan, Ahmad Adnan Qidan, Taisir Elgorashi, Jaafar Elmirghani","doi":"10.1038/s44459-026-00062-x","DOIUrl":"10.1038/s44459-026-00062-x","url":null,"abstract":"Non-orthogonal multiple access (NOMA) is a promising technique for optical wireless communication (OWC), enabling multiple users to share the optical spectrum simultaneously through the power domain. However, imperfect channel state information (CSI) and residual decoding errors deteriorate NOMA performance, especially in realistic dense-user indoor scenarios. In this work, we model an OWC system that integrates light detection and localization (LiDAL) and random linear network coding (RLNC) within a NOMA framework. LiDAL exploits spatio-temporal information to improve user CSI, while RLNC enhances data resilience in the successive decoding process, resulting in a LiDAL-assisted RLNC-NOMA OWC system. Power allocation (PA) is crucial in this system due to complex interactions between multiple users and the coding and detection processes, but optimizing continuous PA dynamically can be computationally prohibitive. To address this, we adopt a deep reinforcement learning (DRL) framework to efficiently learn near-optimal PA strategies. In particular, a DRL-based normalized advantage function (NAF) algorithm is proposed to maximize the average sum rate, and its performance is compared to deep deterministic policy gradient (DDPG), gain ratio PA (GRPA), and exhaustive search. The results indicate that NAF closely matches exhaustive search, is 39% faster than DDPG, and improves the average sum rate by 4.6% over GRPA, while accounting for user location estimation errors.","PeriodicalId":521122,"journal":{"name":"NPJ wireless technology","volume":"2 1","pages":"49"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13437240/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148682078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Passive spatial sampling of mmWave and sub-THz propagation channels using omnidirectional lens antennas. 利用全向透镜天线对毫米波和亚太赫兹传播信道进行无源空间采样。

NPJ wireless technology Pub Date : 2026-01-01 Epub Date: 2026-09-23 DOI: 10.1038/s44459-026-00085-4

Valentina Cicchetti, Andre Saker Andy, Theo Saunders, Jiahao Hu, Sana Salous, Yang Hao

{"title":"Passive spatial sampling of mmWave and sub-THz propagation channels using omnidirectional lens antennas.","authors":"Valentina Cicchetti, Andre Saker Andy, Theo Saunders, Jiahao Hu, Sana Salous, Yang Hao","doi":"10.1038/s44459-026-00085-4","DOIUrl":"10.1038/s44459-026-00085-4","url":null,"abstract":"6G wireless systems promise extreme data rates and dense spatial multiplexing, yet accurate characterization of propagation channels at mmWave and sub-THz frequencies remains challenging due to severe path loss and reliance on mechanically scanned directional antennas. Here, we demonstrate a wideband omnidirectional lens architecture enabling uniform near-horizon spatial sampling across the 75-100 GHz and 220-300 GHz bands. The design combines symmetric waveguide excitation, a conical field redistribution stage, and a dielectric lens to impose a transverse phase profile, producing stable azimuthal radiation with minimal angular bias. Functioning as a passive spatial sampling interface, the antenna captures multipath components across the full azimuth without mechanical scanning. Additively manufactured prototypes exhibit broadband impedance matching and realized gains of 7-8 dBi, with measurements matching full-wave simulations up to 300 GHz. Integrated into a wideband channel sounder in a SISO configuration, the platform enables the extraction of channel parameters in indoor environments, providing a scalable approach to channel characterization and future MIMO-relevant propagation modeling for 6G systems.","PeriodicalId":521122,"journal":{"name":"NPJ wireless technology","volume":"2 1","pages":"72"},"PeriodicalIF":0.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13600917/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149043380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A comprehensive comparison between Terahertz and optical wireless communications. 太赫兹与光学无线通信的综合比较。

NPJ wireless technology Pub Date : 2025-01-01 Epub Date: 2025-11-06 DOI: 10.1038/s44459-025-00002-1

Mingqing Liu, Hossein Kazemi, Majid Safari, Iman Tavakkolnia, Harald Haas

{"title":"A comprehensive comparison between Terahertz and optical wireless communications.","authors":"Mingqing Liu, Hossein Kazemi, Majid Safari, Iman Tavakkolnia, Harald Haas","doi":"10.1038/s44459-025-00002-1","DOIUrl":"https://doi.org/10.1038/s44459-025-00002-1","url":null,"abstract":"This paper presents a comprehensive quantitative comparison between Terahertz (THz) communication and optical wireless communication (OWC) technologies, with a focus on indoor and outdoor deployment scenarios. For indoor environments, we compare THz and vertical-cavity surface-emitting laser (VCSEL)-based OWC systems by incorporating misalignment effects using a multi-ray THz channel model with antenna patterns and a Gaussian beam model for VCSELs. Unified beamwidth assumptions enable consistent evaluation. We further develop power consumption models capturing THz phase noise, VCSEL nonlinearities, and photodetector bandwidth-area tradeoffs, facilitating a detailed energy efficiency analysis under multi-transmitter coverage. For outdoor scenarios, we survey existing stochastic channel models that characterize path loss, pointing errors, and small-scale fading for both THz and free space optics (FSO) links. These models are applied to unmanned aerial vehicle (UAV)-based use cases to evaluate communication robustness under dynamic conditions. Our findings highlight critical performance tradeoffs and deployment challenges, offering insights into the relative advantages of THz and OWC technologies in diverse environments.","PeriodicalId":521122,"journal":{"name":"NPJ wireless technology","volume":"1 1","pages":"3"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12648704/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145644784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0