IEEE Open Journal of the Communications Society最新文献

{"title":"Robust Communication Design in RIS-Assisted THz Channels","authors":"Yasemin Karacora;Adam Umra;Aydin Sezgin","doi":"10.1109/OJCOMS.2025.3541315","DOIUrl":"https://doi.org/10.1109/OJCOMS.2025.3541315","url":null,"abstract":"Terahertz (THz) communication offers the necessary bandwidth to meet the high data rate demands of next-generation wireless systems. However, it faces significant challenges, including severe path loss, dynamic blockages, and beam misalignment, which jeopardize communication reliability. Given that many 6G use cases require both high data rates and strong reliability, robust transmission schemes that achieve high throughput under these challenging conditions are essential for the effective use of high-frequency bands. In this context, we propose a novel mixed-criticality superposition coding scheme for reconfigurable intelligent surface (RIS)-assisted THz systems. This scheme leverages both the strong but intermittent direct line-of-sight link and the more reliable, yet weaker, RIS path to ensure robust delivery of high-criticality data while maintaining high overall throughput. We model a mixed-criticality queuing system and optimize transmit power to meet reliability and queue stability constraints. Simulation results show that our approach significantly reduces queuing delays for critical data while sustaining high overall throughput, outperforming conventional time-sharing methods. Additionally, we examine the impact of blockage, beam misalignment, and beamwidth adaptation on system performance. These results demonstrate that our scheme effectively balances reliability and throughput under challenging conditions, while also underscoring the need for robust beamforming techniques to mitigate the impact of misalignment in RIS-assisted channels.","PeriodicalId":33803,"journal":{"name":"IEEE Open Journal of the Communications Society","volume":"6 ","pages":"3029-3043"},"PeriodicalIF":6.3,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10883649","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848906","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}

{"title":"Faster Convergence With Less Communication: Broadcast-Based Subgraph Sampling for Decentralized Learning Over Wireless Networks","authors":"Daniel Pérez Herrera;Zheng Chen;Erik G. Larsson","doi":"10.1109/OJCOMS.2025.3540133","DOIUrl":"https://doi.org/10.1109/OJCOMS.2025.3540133","url":null,"abstract":"Decentralized stochastic gradient descent (D-SGD) is a widely adopted optimization algorithm for decentralized training of machine learning models across networked agents. A crucial part of D-SGD is the consensus-based model averaging, which heavily relies on information exchange and fusion among the nodes. For consensus averaging over wireless networks, due to the broadcast nature of wireless channels, simultaneous transmissions from multiple nodes may cause packet collisions if they share a common receiver. Therefore, communication coordination is necessary to determine when and how a node can transmit (or receive) information to (or from) its neighbors. In this work, we propose <monospace>BASS</monospace>, a broadcast-based subgraph sampling method designed to accelerate the convergence of D-SGD while considering the actual communication cost per iteration. <monospace>BASS</monospace> creates a set of mixing matrix candidates that represent sparser subgraphs of the base topology. In each consensus iteration, one mixing matrix is randomly sampled, leading to a specific scheduling decision that activates multiple collision-free subsets of nodes. The sampling occurs in a probabilistic manner, and the elements of the mixing matrices, along with their sampling probabilities, are jointly optimized. Simulation results demonstrate that <monospace>BASS</monospace> achieves faster convergence and requires fewer transmission slots than existing link-based scheduling methods and the full communication scenario. In conclusion, the inherent broadcasting nature of wireless channels offers intrinsic advantages in accelerating the convergence of decentralized optimization and learning.","PeriodicalId":33803,"journal":{"name":"IEEE Open Journal of the Communications Society","volume":"6 ","pages":"1497-1511"},"PeriodicalIF":6.3,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10879080","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143583114","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}

{"title":"The Role of Digital Twin in 6G-Based URLLCs: Current Contributions, Research Challenges, and Next Directions","authors":"Antonino Masaracchia;Dang van Huynh;Trung Q. Duong;Octavia A. Dobre;Arumugam Nallanathan;Berk Canberk","doi":"10.1109/OJCOMS.2025.3540287","DOIUrl":"https://doi.org/10.1109/OJCOMS.2025.3540287","url":null,"abstract":"Substantial improvements in the area of ultra reliable and low-latency communication (URLLC) capabilities, as well as possibilities of meeting the rising demand for high-capacity and high-speed connectivity are expected to be achieved with the deployment of next generation 6G wireless communication networks. This thank to the adoption of key technologies such as unmanned aerial vehicles (UAVs), reflective intelligent surfaces (RIS), and mobile edge computing (MEC), which hold the potential to enhance coverage, signal quality, and computational efficiency. However, the integration of these technologies presents new optimization challenges, particularly for ensuring network reliability and maintaining stringent latency requirements. The Digital Twin (DT) paradigm, coupled with artificial intelligence (AI) and deep reinforcement learning (DRL), is emerging as a promising solution, enabling real-time optimization by digitally replicating network devices to support informed decision-making. This paper reviews recent advances in DT-enabled URLLC frameworks, highlights critical challenges, and suggests future research directions for realizing the full potential of 6G networks in supporting next-generation services under URLLCs requirements.","PeriodicalId":33803,"journal":{"name":"IEEE Open Journal of the Communications Society","volume":"6 ","pages":"1202-1215"},"PeriodicalIF":6.3,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10879074","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143455289","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}

{"title":"Low-Complexity Oversampled OTFS Receivers With Reduced Overhead","authors":"Narendra Deconda;Srikrishna Bhashyam;Nambi Seshadri;R. David Koilpillai","doi":"10.1109/OJCOMS.2025.3540356","DOIUrl":"https://doi.org/10.1109/OJCOMS.2025.3540356","url":null,"abstract":"Orthogonal Time Frequency Space (OTFS) modulation enables reliable communication in fast time-varying, frequency-selective channels. It is a delay-Doppler (DD) domain modulation that models the information symbols and the channel in the DD domain. This paper considers a pulse-shaped OTFS system with oversampling at the receiver. To mitigate Inter-Frame and Inter-Block Interference, we propose a Reduced Cyclic Prefix (RCP) and Reduced Cyclic Suffix (RCS) frame structure for the OTFS systems that need significantly less overhead than the existing Zero-padded OTFS frame structure. At the receiver, we propose a Finite Impulse Response filter-based Noise Whitening and an iterative delay-time domain Maximal Ratio Combining equalizer that has low complexity and employs oversampling. Through Monte Carlo simulations, we show improved system error performance with oversampling and excess bandwidth. The proposed equalizer provides a significant complexity reduction compared to the existing Message-passing equalizer for a minimal degradation in error performance. We then simulate a Matched Filter Bound (MFB) for OTFS systems. The proposed equalizer is within 3 dB of the MFB performance at an error rate of 10-4.","PeriodicalId":33803,"journal":{"name":"IEEE Open Journal of the Communications Society","volume":"6 ","pages":"1-1"},"PeriodicalIF":6.3,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10879026","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848844","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}

{"title":"Trustworthy Reputation for Federated Learning in O-RAN Using Blockchain and Smart Contracts","authors":"Farhana Javed;Josep Mangues-Bafalluy;Engin Zeydan;Luis Blanco","doi":"10.1109/OJCOMS.2025.3540159","DOIUrl":"https://doi.org/10.1109/OJCOMS.2025.3540159","url":null,"abstract":"This paper proposes a blockchain-enabled framework to enhance trust, transparency, and collaboration in Open Radio Access Network (O-RAN) infrastructures through Federated Learning (FL). Traditional O-RAN architectures and centralized machine learning approaches face challenges when integrating multi-vendor environments, primarily due to lack of trust, proprietary data concerns, and limited interoperability. Our solution transitions from implicit trust, where the reliability of contributions is assumed, to explicit trust, where reputation is verifiably established on-chain. We introduce a blockchain-based reputation mechanism that evaluates the accuracy, integrity, and quality of participants’ model updates within the FL process. Smart contracts automate critical tasks-such as participant registration, model update verification, and reputation scoring-ensuring that data inputs directly influence accountability in a tamper-proof, transparent manner. By deploying the framework on a scalable Layer 2 blockchain (Polygon) testnet and proposing the use of a blockchain oracle within this architectural framework for secure off-chain computations, this work focuses on a conceptual architectural approach by aligning with O-RAN’s architecture to propose and deploy a Decentralized Application (DApp) on the blockchain. The proposed framework emphasizes a conceptual design over performance optimization and is structured to naturally benefit from ongoing improvements in blockchain scalability, which may reduce latency and enhance operational efficiency over time. Smart contracts for crucial processes and reputation calculation are included within our proposed DApp. The implementation of this work is publicly accessible <uri>https://github.com/farhanajaved/Reputation_O-RAN</uri>.","PeriodicalId":33803,"journal":{"name":"IEEE Open Journal of the Communications Society","volume":"6 ","pages":"1343-1362"},"PeriodicalIF":6.3,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10879031","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143489187","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}

{"title":"Generative AI-Empowered RFID Sensing for 3D Human Pose Augmentation and Completion","authors":"Ziqi Wang;Shiwen Mao","doi":"10.1109/OJCOMS.2025.3539705","DOIUrl":"https://doi.org/10.1109/OJCOMS.2025.3539705","url":null,"abstract":"Collecting paired Radio Frequency Identification (RFID) data and corresponding 3D human pose data is challenging due to practical limitations, such as the discomfort of wearing numerous RFID tags and the inconvenience of timestamp synchronization between RFID and camera data. We propose a novel framework that leverages latent diffusion transformers to generate high-quality, diverse RFID sensing data across multiple classes. This synthetic data augments limited datasets by training a transformer-based kinematics predictor to estimate 3D poses with temporal smoothness from RFID data. Most importantly, we introduce a latent diffusion transformer training stage with cross-attention conditioning and an inference design of two-stage velocity alignment to accurately infer missing joints in skeletal poses, completing full 25-joint configurations from partial 12-joint inputs. This is the first method to detect >20 distinct skeletal joints using Generative-AI technologies for any wireless sensing-based continuous 3D human pose estimation (HPE) task. The application is particularly important for RFID-based systems, which typically capture limited joint information due to RFID sensing constraints. Our approach can extend the applicability of wireless-based pose estimation in scenarios where collecting extensive paired datasets is impractical and achieving more fine-grained joint information is infeasible, such as pedestrian and health monitoring in occluded environments.","PeriodicalId":33803,"journal":{"name":"IEEE Open Journal of the Communications Society","volume":"6 ","pages":"1-1"},"PeriodicalIF":6.3,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10877927","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848809","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}

{"title":"Efficient Spatial Channel Estimation in Extremely Large Antenna Array Communication Systems: A Subspace Approximated Matrix Completion Approach","authors":"Zhiwei Chen;Quanfeng Yao;Yi Zhong;Junliang Ye;Xiaohu Ge","doi":"10.1109/OJCOMS.2025.3539936","DOIUrl":"https://doi.org/10.1109/OJCOMS.2025.3539936","url":null,"abstract":"Matrix completion techniques are widely employed to estimate the channel matrix from partially observed channel measurements. However, its computational complexity is cubic in the number of antennas, which is non-scalable for extremely large-scale antenna array (ELAA) communication systems. To address this issue, in this paper the ELAA channel matrix completion is reformulated as a proximal gradient descent (PGD) problem, where the subgradient of the nuclear norm is computed by singular value thresholding (SVT) operator and the proximal gradient of the <inline-formula> <tex-math>$L_{1}$ </tex-math></inline-formula> norm is derived using a softthresholding operator. To mitigate the computational overhead caused by subspace orthogonalization in the SVT operation, a novel subspace-approximated (SA)-SVT-PGD algorithm is designed. This algorithm exploits the subspace similarity of the channel’s Gram matrix in consecutive PGD iterations and enables concurrent subspace orthogonalization during PGD updates. By eliminating the specific nested loop for the subspace orthogonalization, the computational complexity of the SA-SVT-PGD algorithm is proportional to the product between the number of antennas and the square of rank of the channel matrix. Simulation results demonstrate that the SA-SVT-PGD algorithm can reduce the convergence time by 71.7% compared with the traditional SVT-PGD algorithm.","PeriodicalId":33803,"journal":{"name":"IEEE Open Journal of the Communications Society","volume":"6 ","pages":"1216-1230"},"PeriodicalIF":6.3,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10877855","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143455293","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}

{"title":"On the Performance of STAR-RIS-Aided mmWave MIMO–NOMA Transmission Using Stochastic Geometry: Phase Shift Error Case","authors":"Farid Tabee Miandoab;Behzad Mozaffari Tazehkand","doi":"10.1109/OJCOMS.2025.3539966","DOIUrl":"https://doi.org/10.1109/OJCOMS.2025.3539966","url":null,"abstract":"This work combines non-orthogonal multiple-access (NOMA) and millimeter-wave (mmWave) in a reconfigurable intelligent surface (RIS)-aided multiple-input multiple-output (MIMO) communication system, in which the RIS can simultaneously transmit and reflect signals (STAR-RIS). To adjust the STAR-RIS phase shift responses, we consider scenarios where the cascade channel phase information is available either perfectly or imperfectly. The stochastic geometric model is utilized to model the locations of the randomly deployed users. The users are divided into the cell-center users’ group and the cell-edge users’ group. To implement NOMA, we consider two user selection frameworks: 1) random user selection and 2) nearest user selection. For random users selection, one user from each group is randomly selected to be paired, while one user from each group with the shortest distance relative to STAR-RIS is selected in the nearest user selection strategy. To reduce system overhead and latency caused by the requirement to obtain channel state information (CSI) of all users, a beamforming approach is employed in the base station (BS). We derive the effective channel powers and provide the analytical expressions of the outage probability and outage sum rate for scenarios with and without error in the phase shift response of STAR-RIS. Besides, we provide an asymptotic analysis and derive the lower bound for outage probability when there are phase errors in the STAR-RIS phase shifts. We further analyze the impact of active STAR-RIS and imperfect CSI on the system performance. Simulation results are provided to validate our analyses and illustrate the effectiveness of establishing unobstructed transmission and reflection links in dead zones, thereby enhancing the reliability of communications.","PeriodicalId":33803,"journal":{"name":"IEEE Open Journal of the Communications Society","volume":"6 ","pages":"1328-1342"},"PeriodicalIF":6.3,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10877923","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465635","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}

{"title":"Measuring Mobile Starlink Performance: A Comprehensive Look","authors":"Dominic Laniewski;Eric Lanfer;Nils Aschenbruck","doi":"10.1109/OJCOMS.2025.3539836","DOIUrl":"https://doi.org/10.1109/OJCOMS.2025.3539836","url":null,"abstract":"With the recent success of Low Earth Orbit (LEO) satellite networks, such as SpaceX’s Starlink, measuring their performance has been of great interest to the community. While stationary Starlink performance has been extensively assessed on a globalized view, mobile - in-motion - usage is relatively new. A first look at its performance has only been taken by three studies so far. In this paper, we take a comprehensive look at mobile Starlink performance from the measurement perspective by answering the following three research questions: (1) How does mobile Starlink performance differ in different regions of the world? (2) How does the mobile performance compare to stationary performance? (3) How does obstruction impact mobile performance? To answer these questions, we conduct our own 300 km long test-drive on the German Autobahn (highway) with car velocities up to 140 km/h. We compare our results to the datasets of the other three studies and to stationary measurements. To the best of our knowledge, we are the first to deeper analyze the impact of obstructions on the performance. For this, we map bridges crossing the highway to our measurements and find that these short total obstructions cause significant burst packet loss, RTT spikes, and throughput drops. We show that mobility-induced instabilities can have a severe negative impact on the performance of higher-level applications such as HTTP bulk file transfer.","PeriodicalId":33803,"journal":{"name":"IEEE Open Journal of the Communications Society","volume":"6 ","pages":"1266-1283"},"PeriodicalIF":6.3,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10877858","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465627","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}

{"title":"Toward Proactive, Secure and Efficient Space-Air-Ground Communications: Generative AI-Based DRL Framework","authors":"Amayika Kakati;Guoquan Li;Elhadj Moustapha Diallo;Lilian Chiru Kawala;Nasir Hussain;Abuzar B. M. Adam","doi":"10.1109/OJCOMS.2025.3539355","DOIUrl":"https://doi.org/10.1109/OJCOMS.2025.3539355","url":null,"abstract":"The rapid growth of low-Earth-orbit (LEO) satellites has enabled integrated space-air-ground networks to provide seamless connectivity to mobile users. However, these networks face challenges such as physical layer security risks from line-of-sight channels and the energy constraints of high-altitude platforms (HAPs), necessitating solutions for secure communication and energy efficiency. In this work, we address the challenges of energy efficiency and secure communication in space-air-ground networks, which are becoming critical with the increasing deployment of LEO satellites to support high-mobility users. We propose a novel downlink architecture where high-altitude platforms (HAPs) assist the LEO satellite in serving ground users. To tackle the demands of secrecy energy efficiency (SEE) in this dynamic and complex network, we formulate a non-convex optimization problem that jointly considers HAP trajectory, user-HAP association, and beamforming. The problem’s non-convexity makes it computationally challenging to solve in polynomial time. To overcome these challenges, we introduce a generative artificial intelligence (GAI)-based deep reinforcement learning (DRL) framework, named Gen-DRL, which leverages generative adversarial networks to empower its agents. This framework dynamically predicts and adapts to changes in the space-air-ground network environment by optimizing key parameters such as channel states, HAP trajectories, user associations, and beamforming. Compared to conventional methods, the proposed Gen-DRL achieves significant improvements in SEE by effectively managing complex interdependencies among multiple agents and intelligently adapting to the network’s goals and constraints. Extensive simulation results demonstrate that Gen-DRL consistently outperforms existing state-of-the-art frameworks in terms of secrecy energy efficiency, robustness to dynamic user locations, and adaptability to varying network parameters. This work provides new insights into the design of secure and energy-efficient space-air-ground networks, highlighting the potential of GAI-based DRL for future communication systems.","PeriodicalId":33803,"journal":{"name":"IEEE Open Journal of the Communications Society","volume":"6 ","pages":"1284-1298"},"PeriodicalIF":6.3,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10876168","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465628","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}