{"title":"Dynamic Convolution and Transformer Based Dual-Branch Coding in Semantic Communication System","authors":"Jiaxin Yang;Zhiquan Bai;Xiaodong Xu;Xuchao Teng;Mengying Sun;KyungSup Kwak","doi":"10.1109/LCOMM.2025.3557421","DOIUrl":"https://doi.org/10.1109/LCOMM.2025.3557421","url":null,"abstract":"Semantic communication is a potential key technology in 6G intelligent communication era. To reduce the information redundancy and improve the accuracy of text data transmission, this letter proposes a novel dual-branch joint source-channel coding model in semantic communication system that integrates dynamic convolution (DynConv) with Transformer architecture. The system utilizes the convolutional attention mechanism to capture the local semantic details and the Transformer self-attention mechanism for contextual associations within sentences. In particular, we further investigate the dimension allocation strategy between these two attention mechanisms, seeking the optimal balance between the recovery performance and complexity of the system. Simulation results demonstrate that, compared with the traditional communication system and the typical semantic communication system based on the standard Transformer, the proposed system achieves higher recovery performance, better robustness, and lower complexity.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"29 5","pages":"1161-1165"},"PeriodicalIF":3.7,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143931313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Wavelet-Based Three-Dimensional OTFS With Dual-Mode Index Modulation","authors":"Zhenxing Chen;Si Ouyang","doi":"10.1109/LCOMM.2025.3557036","DOIUrl":"https://doi.org/10.1109/LCOMM.2025.3557036","url":null,"abstract":"In this letter, we propose a new transmission scheme for the next-generation wireless communications called wavelet-based three-dimensional orthogonal time frequency space with dual-mode index modulation (W-3D-OTFS-DM-IM). To enhance the spectral efficiency, the transmitted information bits are mapped into the OTFS frame in the delay-doppler domain using a dual-mode index modulation with 3D signal constellations. The wavelet transform instead of the conventional Fourier transform is applied to achieve OTFS modulation for reduction of complexity and improvement of error performance. The Mallat algorithm is exploited to form the wavelet transform matrix. Simulation results show that the proposed W-3D-OTFS-DM-IM has obviously better bit error rate (BER) performance and spectral efficiency than the reference systems in the high-mobility communication scenarios.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"29 5","pages":"1151-1155"},"PeriodicalIF":3.7,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143932233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Physical IoU-Based YOLO Network for Shortwave Communication Burst Signal Recognition","authors":"Xiaojun Zhu;Yinsen Luan;Paihang Zhao;Tao Tang;Zhidong Wu","doi":"10.1109/LCOMM.2025.3557043","DOIUrl":"https://doi.org/10.1109/LCOMM.2025.3557043","url":null,"abstract":"Shortwave communication plays a critical role in military and emergency applications. However, the complex nature of shortwave transmission channels makes automatic burst signal recognition particularly challenging, especially in non-cooperative scenarios. This letter presents an optimized recognition method based on the You Only Look Once (YOLO) network, which accurately identifies signal types while improving the precision of burst time detection. A Physical Intersection over Union (PIoU) is proposed by leveraging the bounding box’s left edge, corresponding to signal burst time, to refine bounding box regression and resolve ambiguities in conventional IoUs. Experiments show the proposed PIoU improves the accuracy of burst time detection by 10.44% under Signal-to-Noise Ratios (SNRs) from -20dB to 18dB, compared to the state-of-the-art IoU methods. Further tests across 8 shortwave communication channels confirm consistent improvements of burst time detection, while other metrics such as Precision, Recall, mean Average Precision at 50% IoU(mAP50), and mAP95 are maintained. These advancements significantly benefit signal decoding and information restoration.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"29 5","pages":"1156-1160"},"PeriodicalIF":3.7,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143931314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Deep Joint Source-Channel Coding of Underwater Image Enhancement in AUV Swarms","authors":"Zhenguo Zhang;Guang Liu;Minghui Wang;Bo Chen;Zesheng Liu;Xiaojie Zhang","doi":"10.1109/LCOMM.2025.3556673","DOIUrl":"https://doi.org/10.1109/LCOMM.2025.3556673","url":null,"abstract":"Underwater images commonly suffer from visual degradation due to the complexities of the underwater imaging and transmission environments. To address this issue, we propose a lightweight system for underwater image enhancement and transmission tailored for autonomous underwater vehicle swarms, improving both image quality and communication efficiency with surface equipment. The proposed model enables a target-oriented multi-space feature encoding network to process degraded pixels, followed by a reinforcement learning-based bandwidth allocation network that optimizes feature distribution under constrained bandwidth conditions. Simulation results demonstrate that the proposed system significantly enhances the speed and effectiveness of image recovery under varying channel conditions.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"29 5","pages":"1146-1150"},"PeriodicalIF":3.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143931311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"FSIM-Net: Neural Network-Based Symbol Detector for Filter Shape Index Modulation","authors":"Shubham Anand;Haïfa Farès;Majed Saad;Preetam Kumar","doi":"10.1109/LCOMM.2025.3556431","DOIUrl":"https://doi.org/10.1109/LCOMM.2025.3556431","url":null,"abstract":"Filter shape index modulation (FSIM) is a promising approach that unlike most existing index modulation schemes does not sacrifice resource utilization by deactivating available resources but rather uses pulse shaping filters as indexing parameters. This principle is the key to enhance spectral efficiency and/or energy efficiency. However, the filter bank design relaxes the Nyquist criterion for zero intersymbol interference (ISI) to have more distinguishable filters and the inherent controlled ISI can be managed at the receiver side. This letter presents FSIM-Net, a simple neural network (NN)-based detector that enables joint detection of filter indices and QAM/PSK symbols in the presence of filters’ inherent ISI. FSIM-Net is trained offline in an additive white Gaussian noise (AWGN) channel and tested under various conditions by decoupling of inherent ISI and channel effect handling. The proposed receiver demonstrates superior performance especially in more realistic scenarios while simplifying the FSIM receiver architecture and avoiding potential error propagation compared to the conventional one.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"29 5","pages":"1141-1145"},"PeriodicalIF":3.7,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143932262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hao-Bing Sun;Jian Li;Xing-Wang Chu;Jing-Yang Liu;Hua-Jian Ding;Qin Wang
{"title":"Optimized Qubit-Based Synchronization in Quantum Key Distribution","authors":"Hao-Bing Sun;Jian Li;Xing-Wang Chu;Jing-Yang Liu;Hua-Jian Ding;Qin Wang","doi":"10.1109/LCOMM.2025.3554260","DOIUrl":"https://doi.org/10.1109/LCOMM.2025.3554260","url":null,"abstract":"Quantum key distribution (QKD) enables the generation of information-theoretic secure keys between two remote parties. A critical component of successful QKD implementation is the effective synchronization of clocks between these users. Traditional methods of locking to a reference clock or transmitting a synchronization signal rely on auxiliary equipment, which increases the complexity and cost, thus hindering the widespread deployment of QKD. Here, we propose a method to achieve clock and pulse synchronization by exploiting a subset of the transmitted qubits. We demonstrate our scheme with a time-bin phase-coding BB84 QKD system and verify the realization of long-term stable key generation over distances of 50 km and 100 km. Our method simplifies the implementation of QKD systems and introduces new possibilities for synchronization algorithms in other quantum communication protocols.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"29 5","pages":"1087-1091"},"PeriodicalIF":3.7,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143938024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Space-to-Ground Optical Communication Downlink Scheduling Under Uncertainty of Link Availability","authors":"Pei Lyu;Kanglian Zhao;Shihao Wang;Hangsheng Zhao","doi":"10.1109/LCOMM.2025.3555945","DOIUrl":"https://doi.org/10.1109/LCOMM.2025.3555945","url":null,"abstract":"Space-to-ground optical communication (STGOC) utilizes laser beams to establish bidirectional links between satellites and ground stations (GSs), which are sensitive to cloud blockage. In practical STGOC downlink scheduling, the uncertainty of link availability caused by cloud motion and dissipation is inevitable. We are the first to address STGOC downlink scheduling under the uncertainty of link availability, where the objective function aims to maximize the amount of data downloaded from the satellites. We provide a formulation of the scheduling problem based on Scenario Generation Approximating (SGA) while preserving the formulation linearity. A Greedy Heuristic-based algorithm is designed to solve the problem. Simulation results indicate that considering uncertainty can enhance data throughput, with the average optimality gap being 0.61%, while the running time is reduced compared to Gurobi and Kuhn-Munkres-based methods.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"29 5","pages":"1136-1140"},"PeriodicalIF":3.7,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143932263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yijian Hou;Kaisa Zhang;Gang Chuai;Weidong Gao;Xiangyu Chen;Siqi Liu
{"title":"Service Association and Subcarrier Allocation in Vehicular Slicing Networks With Dynamic Multi-Service","authors":"Yijian Hou;Kaisa Zhang;Gang Chuai;Weidong Gao;Xiangyu Chen;Siqi Liu","doi":"10.1109/LCOMM.2025.3555768","DOIUrl":"https://doi.org/10.1109/LCOMM.2025.3555768","url":null,"abstract":"The vehicular slicing network with dynamic multi-service (VSN-DMS) enables vehicles to support multiple services with dynamically changing types. In this architecture, vehicles can access multiple base stations (BSs) and leverage different network slices (NSs) to meet the requirements of various services. However, frequent service variations and vehicle mobility introduce high handover (HO) costs and inefficient decision making. This letter proposes a novel two-timescale optimization framework to jointly optimize vehicle service (VS) association and subcarrier (SC) allocation. Specifically, in the long-timescale, we propose a federated deep reinforcement learning (FDRL) algorithm to optimize VS association. Unlike conventional reinforcement learning approaches that require centralized data collection, FDRL enables distributed model training across vehicles while aggregating parameters in the cloud. This mitigates the issue of insufficient training data caused by frequent VS changes, while also ensuring vehicle data privacy. In the short-timescale, we propose a versatile alternating coalitional game and swap-matching game algorithm (ACGSM) to optimize SC allocation. By iteratively executing coalitional formation and swap-matching mechanisms, ACGSM efficiently improves the quality of the solution while adapting to dynamic network conditions. Simulation results demonstrate the convergence of FDRL and show that the proposal outperforms benchmarks in improving long-term QoS and reducing the number of HOs.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"29 5","pages":"1131-1135"},"PeriodicalIF":3.7,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143932261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xin Wang;Can Zheng;Pengjiang Hu;Junan Yang;Chung G. Kang
{"title":"A Sparsity-Agnostic SL0 Channel Estimation Approach for OTFS Systems","authors":"Xin Wang;Can Zheng;Pengjiang Hu;Junan Yang;Chung G. Kang","doi":"10.1109/LCOMM.2025.3554379","DOIUrl":"https://doi.org/10.1109/LCOMM.2025.3554379","url":null,"abstract":"Orthogonal time frequency space (OTFS) modulation has been shown to support reliable communication in high mobility scenarios. Due to the sparsity of the delay-Doppler (DD) domain, most existing algorithms utilize compressed sensing (CS) for OTFS channel estimation, while requiring a known channel sparsity. However, in cases that the sparsity is not readily accessible, the estimation accuracy of these CS algorithms decreases dramatically. In this letter, we propose a Smoothed <inline-formula> <tex-math>$ell _{0}$ </tex-math></inline-formula> (SL0) algorithm free of prior knowledge about channel sparsity for OTFS channel estimation. We obtain a novel vector expression of the input-output relationship in the DD domain and formulate it as a sparse signal recovery problem. In the case of unknown sparsity, a low-complexity SL0 algorithm is introduced to solve the problem with a faster reconstruction speed. Simulation results show that the proposed algorithm has significant advantages in estimation accuracy and complexity compared to algorithms that also do not require channel sparsity.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"29 5","pages":"1097-1101"},"PeriodicalIF":3.7,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143937964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}