Xin Wang;Jianhui Lv;Adam Slowik;Byung-Gyu Kim;B. D. Parameshachari;Keqin Li
{"title":"Low-Complexity Beamforming Design for Green Near-Field Communications in 6G Ultra-Massive Multiple-Input-Multiple-Output","authors":"Xin Wang;Jianhui Lv;Adam Slowik;Byung-Gyu Kim;B. D. Parameshachari;Keqin Li","doi":"10.1109/TGCN.2024.3416904","DOIUrl":"https://doi.org/10.1109/TGCN.2024.3416904","url":null,"abstract":"The ultra-massive multiple-input-multiple-output (UM-MIMO) is envisioned to be an integral part of future sixth-generation (6G) communication networks to meet the ever-increasing demand for higher data rates. However, the excessive energy consumption of UM-MIMO’s massive radio frequency chains and performance degradation due to beam misalignment pose critical challenges. This paper investigates low-complexity beamforming optimizations with UM-MIMO for green near-field (NF) wireless communications. We first propose an adjustable orientation discontinuous reception (A-ODRX) mechanism merging the beam alignment state into long DRX cycles to reduce power consumption while preserving beamforming capabilities enabled by UM-MIMO’s large aperture. The A-ODRX mechanism demonstrates provable robustness against beam misalignments through theoretical derivations. We designed a phase extraction zero-forcing (PE-ZF) aided hybrid beamforming architecture tailored for NF channels’ spherical waveform effects to further overcome hardware constraints. Simulation results demonstrate that the proposed low-complexity beamforming design for the green NF wireless communication method outperforms benchmarks in terms of energy efficiency, achievable sum rate, rate scaling with users, resilience to NF mobility, and beamforming gain.","PeriodicalId":13052,"journal":{"name":"IEEE Transactions on Green Communications and Networking","volume":"9 1","pages":"317-326"},"PeriodicalIF":5.3,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143403782","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ming Ye;Xiao Liang;Cunhua Pan;Yinfei Xu;Ming Jiang;Chunguo Li
{"title":"GAN-Based Near-Field Channel Estimation for Extremely Large-Scale MIMO Systems","authors":"Ming Ye;Xiao Liang;Cunhua Pan;Yinfei Xu;Ming Jiang;Chunguo Li","doi":"10.1109/TGCN.2024.3416617","DOIUrl":"https://doi.org/10.1109/TGCN.2024.3416617","url":null,"abstract":"Extremely large-scale multiple-input-multiple-output (XL-MIMO) is a promising technique to achieve ultra-high spectral efficiency for future 6G communications. The mixed line-of-sight (LoS) and non-line-of-sight (NLoS) XL-MIMO near-field channel model is adopted to describe the XL-MIMO near-field channel accurately. In this paper, a generative adversarial network (GAN) variant based channel estimation method is proposed for XL-MIMO systems. Specifically, the GAN variant is developed to simultaneously estimate the LoS and NLoS path components of the XL-MIMO channel. The initially estimated channels instead of the received signals are input into the GAN variant as the conditional input to generate the XL-MIMO channels more efficiently. The GAN variant not only learns the mapping from the initially estimated channels to the XL-MIMO channels but also learns an adversarial loss. Moreover, we combine the adversarial loss with a conventional loss function to ensure the correct direction of training the generator. To further enhance the estimation performance, we investigate the impact of the hyper-parameter of the loss function on the performance of our method. Simulation results show that the proposed method outperforms the existing channel estimation approaches in the adopted channel model. In addition, the proposed method surpasses the Cram<inline-formula> <tex-math>$acute {mathrm {e}}$ </tex-math></inline-formula>r-Rao lower bound (CRLB) under low pilot overhead.","PeriodicalId":13052,"journal":{"name":"IEEE Transactions on Green Communications and Networking","volume":"9 1","pages":"304-316"},"PeriodicalIF":5.3,"publicationDate":"2024-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Suleman Khan;Gurjot Singh Gaba;Andrei Gurtov;Leonardus J. A. Jansen;Nils Mäurer;Corinna Schmitt
{"title":"Post-Quantum Secure Handover Mechanism for Next-Generation Aviation Communication Networks","authors":"Suleman Khan;Gurjot Singh Gaba;Andrei Gurtov;Leonardus J. A. Jansen;Nils Mäurer;Corinna Schmitt","doi":"10.1109/TGCN.2024.3417298","DOIUrl":"https://doi.org/10.1109/TGCN.2024.3417298","url":null,"abstract":"The L-band Digital Aeronautical Communications System (LDACS) is a key advancement for next-generation aviation networks, enhancing Communication, Navigation, and Surveillance (CNS) capabilities. It operates with VHF Datalink mode 2 (VDLm2) and features a seamless handover mechanism to maintain uninterrupted communication between aircraft and ground stations (GSs), improving safety and efficiency in air traffic management (ATM). However, LDACS’ handover process encounters significant security risks due to inadequate authentication and key agreement between aircraft and ground station controllers (GSCs) during handovers. This vulnerability threatens communications’ confidentiality, integrity, and authenticity, posing risks to flight safety and sensitive data. Therefore, developing and implementing a robust security framework to protect aviation communications is essential. In response, we have proposed a security solution specifically designed to protect LDACS handovers. Our solution uses a mutual authentication and key agreement mechanism tailored for LDACS handovers, ensuring robust security for all types of handovers, including Intra GSC - Intra Aeronautical Telecommunication Network (ATN), Inter GSC - Intra ATN, and Inter GSC - Inter ATN. Our approach utilizes post-quantum cryptography to protect aviation communication systems against potential post-quantum threats, such as unauthorized access to flight data, interception of communication, and spoofing of aircraft identity. Furthermore, our proposed solution has undergone a thorough informal security analysis to ensure its effectiveness in addressing handover challenges and offering robust protection against various threats. It seamlessly integrates with the LDACS framework, delivering low Bit Error Rate (BER) and latency levels, making it a highly reliable approach in practice.","PeriodicalId":13052,"journal":{"name":"IEEE Transactions on Green Communications and Networking","volume":"8 3","pages":"939-955"},"PeriodicalIF":5.3,"publicationDate":"2024-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142090992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Intelligent Reflecting Surface Assisted Integrated Data and Energy Multicast System in Terahertz-Bands","authors":"Qingxiao Huang;Jie Hu;Kun Yang","doi":"10.1109/TGCN.2024.3415030","DOIUrl":"https://doi.org/10.1109/TGCN.2024.3415030","url":null,"abstract":"An intelligent reflect surface (IRS) assisted multi-user integrated data and energy multicast (IDEM) system is investigated. Considering terahertz (THz) downlinks, the spatial asymptotical orthogonality is proved. Our goal is to maximize the minimum achievable rate of data users (DUs) and satisfy the energy harvesting requirements of energy users (EUs) by jointly designing the multicast beam at the transmitter and the reflecting beam at the IRS. Firstly, the solutions obtained by the semidefinite relaxation (SDR) are analysed. Based on the orthogonality, a low-complexity beamforming scheme is proposed. Specifically, the asymptotically optimal analog beamforming structures of IRS and transmitter are proved, respectively. The transmit power is allocated at the transmitter to satisfy the EUs and the asymptotically optimal beamforming structure of the IRS is used to compensate the path-loss of DUs. Then the transmitter and IRS beamformings are obtained in closed form. Finally, a randomization scheme for IRS beamforming is proposed to further improve the IDET performance. The numerical results shows that, the trade-off between wireless data transfer (WDT) and wireless energy transfer (WET) is well achieved. Moreover, the proposed scheme achieves nearly the same spectral efficiency as fully digital transmitter and higher spectral efficiency than the IRS solutions obtained by SDR.","PeriodicalId":13052,"journal":{"name":"IEEE Transactions on Green Communications and Networking","volume":"9 1","pages":"152-163"},"PeriodicalIF":5.3,"publicationDate":"2024-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Elahe Zolala;Mohammad Amir Dastgheib;Hamzeh Beyranvand;Jawad A. Salehi
{"title":"Toward More Energy Efficient VLC Networks: A Study on Space Division Multiplexing and Smart Lighting","authors":"Elahe Zolala;Mohammad Amir Dastgheib;Hamzeh Beyranvand;Jawad A. Salehi","doi":"10.1109/TGCN.2024.3415528","DOIUrl":"https://doi.org/10.1109/TGCN.2024.3415528","url":null,"abstract":"This paper addresses the challenge of enhancing energy efficiency in Visible Light Communication (VLC) networks through Space Division Multiplexing (SDM) and smart lighting integration. We mathematically formulate the problem of energy-efficient multi-user VLC networking with SDM and smart illumination, tailoring the light output according to the users’ demands. To address the arising intricate optimization problem, we propose Clustered Light Emitting Diode (LED) Assignment and Power optimization (CLAP). This heuristic approach leverages density-based spatial clustering for efficient user grouping and employs a greedy sequential algorithm for LED assignment. The constrained optimization by linear approximation technique is employed to determine transmitted optical power levels. By incorporating density functions of achievable rates into precise transmitter models, our study accurately assesses power consumption in VLC system optimization, significantly enhancing energy efficiency. A comparative analysis of three popular VLC network transmitters shows that precise power consumption determination is superior to using common approximations. The proposed methodology showcases remarkable improvements, achieving up to a 55% increase in energy efficiency and up to a 58% reduction in power consumption for a VLC network, with best results observed when utilizing bias-T transmitters, which can accommodate DC biasing, equipped with class AB amplifiers, known for their efficiency.","PeriodicalId":13052,"journal":{"name":"IEEE Transactions on Green Communications and Networking","volume":"9 1","pages":"96-107"},"PeriodicalIF":5.3,"publicationDate":"2024-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Trade-Off Between Renewable Energy Utilizing and Communication Quality for Base Stations: A Heterogeneous Multi-Agent Safe RL Method","authors":"Min Yan;Li Wang;Lianming Xu;Luyang Hou;Zhu Han","doi":"10.1109/TGCN.2024.3415034","DOIUrl":"https://doi.org/10.1109/TGCN.2024.3415034","url":null,"abstract":"The ultra-dense deployment of base stations (BSs) results in significant energy costs, while the increasing use of fluctuating renewable energy sources (RESs) threatens the safe operation of electric network (EN). These issues can be addressed by coordinating BSs’ active/sleep states with RES generation. However, the coordinated decision-making is challenging due to the conflicting goals of maximizing RES utilization, guaranteeing communication quality of service (QoS). In this paper, we design an electric-cellular collaborative network (ECCN) and formulate a joint optimization problem to minimize electric supply and QoS degradation costs, subjecting to EN’s safety constraints. Considering the uncertainty of RES generation and BS traffic, we propose a heterogeneous multi-agent safe reinforcement learning (HMAS-RL) algorithm to solve the problem. HMAS-RL inherits from the centralized critic and decentralized actor framework, where two heterogeneous agents learn a cooperative policy for joint decision-making through two actor networks design that share observations and a team reward. A cost critic network is designed to handle safety constraints, eliminating the need for manual penalty term design and tuning. We validate the proposed method using an IEEE 33-bus electric distribution test feeder. Results demonstrate HMAS-RL achieves superior performance in RES utilization, communication QoS, and EN safety constraints maintenance.","PeriodicalId":13052,"journal":{"name":"IEEE Transactions on Green Communications and Networking","volume":"9 1","pages":"83-95"},"PeriodicalIF":5.3,"publicationDate":"2024-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Saeed Akbar;Ubaid Ul Akbar;Rahmat Ullah;Zhonglong Zheng
{"title":"A Coalitional Game-Based Adaptive Scheduler Leveraging Task Heterogeneity for Greener Data Centers","authors":"Saeed Akbar;Ubaid Ul Akbar;Rahmat Ullah;Zhonglong Zheng","doi":"10.1109/TGCN.2024.3414671","DOIUrl":"https://doi.org/10.1109/TGCN.2024.3414671","url":null,"abstract":"Managing power and its subsequent thermal implications is of paramount concern in modern Data Centers (DCs) management. Failure to adequately address the escalating energy use can result in excessive heat dissipation, leading to thermal imbalances and hotspots. In addition, the prolonged execution of CPU-intensive user jobs on servers operating at higher temperatures can significantly aggravate the DCs cooling efforts. Researchers advocate Thermal-aware (TA) scheduling as a promising tool to counter the said issue. However, existing state-of-the-art overlooks user jobs runtime heterogeneity, potentially causing aggravated heat dissipation when CPU-intensive tasks run on servers at elevated temperatures for longer duration. Moreover, existing works do not provide any mechanism to detect overloaded computing nodes at runtime in a TA context. Finally, existing strategies do not adapt according to the DCs dynamic thermal conditions. This paper offers a Coalitional Game-based Thermal-aware Adaptive Scheduling (CGTAS) tailored for heterogeneous DCs to minimize the cooling cost stemming from excessive heat generated during compute-intensive job execution. CGTAS intelligently differentiates incoming jobs based on their thermal profiles and CPU-time for optimal thermal outcomes. In addition, it dynamically allocates user jobs to computing nodes based on their real-time marginal thermal performance using the Core solution concept from game theory. Finally, unlike existing TA strategies, the proposed design identifies thermally overloaded computing elements using the Core and performs task migrations to optimize thermal-efficiency. Extensive simulations confirm substantial energy savings (up to 26.08%) compared to its TA substitutes, promoting sustainable and high-performance computing infrastructure in large-scale cloud DCs.","PeriodicalId":13052,"journal":{"name":"IEEE Transactions on Green Communications and Networking","volume":"9 1","pages":"55-69"},"PeriodicalIF":5.3,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"A Dual-Hop Uplink IM-OFDMA System With Amplify-and-Forward Relays","authors":"Saud Althunibat;Khalid Qaraqe","doi":"10.1109/TGCN.2024.3411673","DOIUrl":"https://doi.org/10.1109/TGCN.2024.3411673","url":null,"abstract":"Index Modulation based Orthogonal Frequency Division Multiple Access (IM-OFDMA) is an uplink scheme that allows a set of users to share a chunk of frequency subcarriers by the means of IM. IM-OFDMA has shown a promising performance as compared to its counterparts, which makes it a good candidate for future networks. To this end, this paper aims to investigate the performance of a dual-hop IM-OFDMA with the aid of Amplify-and-Forward (AF) relays. Unlike other links, employing AF relaying poses a challenge in IM-OFDMA because the identities and the number of active users over a subcarrier is unknown at the relays, which makes popular amplifying strategies not applicable. As such, a dual-hop uplink IM-OFDMA system requires a new amplifying strategy that is compatible with the data-driven subcarrier activation followed in IM-OFDMA systems. This paper proposes two different amplifying strategies that do not rely on the channel gains between the users and the AF relays. The performance of both amplifying strategies are analytically quantified in terms of the Average Bit Error Rate (ABER) at the base station and the energy consumption at the relays. Analytical and simulation results demonstrate the improvement in BER and energy saving achieved by the proposed dual-hop AF-based IM-OFDMA.","PeriodicalId":13052,"journal":{"name":"IEEE Transactions on Green Communications and Networking","volume":"9 1","pages":"45-54"},"PeriodicalIF":5.3,"publicationDate":"2024-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Optimal Multi-Level Amplitude-Shift Keying for Channel Norm-Based SIMO Wireless Communication System in Rician Fading Environment","authors":"Badri Ramanjaneya Reddy;Soumya P. Dash","doi":"10.1109/TGCN.2024.3411170","DOIUrl":"https://doi.org/10.1109/TGCN.2024.3411170","url":null,"abstract":"An N-branch receive diversity wireless system subject to prominent line-of-sight (LoS) fading in the multipath is considered in this paper. The fading channels are modeled by Rician distributions and the transmitter employs multi-level amplitude-shift keying (ASK) for data modulation. The receiver is assumed to possess the knowledge of the magnitude of the fading channels and thus, an optimal receiver structure based on the knowledge of the channel-norm is derived. Owing to the complexity of the receiver structure, two novel suboptimal receivers, inspired by the central limit theorem and Euclidean distance, are proposed. Furthermore, series-form expressions for the symbol error probability (SEP) for both these receivers are derived. This is followed by proposing and solving an optimization framework aimed at finding the optimal multi-level ASK constellations to minimize the SEP expressions obtained for the two receivers under an average system energy constraint. The analytical framework is verified by numerical studies that show the efficacy of the obtained optimal ASK constellations over the equally-spaced ASK constellations traditionally used for wireless systems. Moreover, it is observed that the traditional Euclidean distance-based receiver isn’t appropriate for optimal performance and the optimal factor <inline-formula> <tex-math>$alpha $ </tex-math></inline-formula> is dependent on the average signal-to-noise ratio and the number of diversity branches. Additionally, the dependencies of the shape of the optimal constellation schemes on the various system parameters are studied via numerical results. Thus, the proposed novel receivers and multi-level ASK schemes provide crucial design insights for reliable, hardware-efficient, and energy-efficient communication systems with prominent LoS links.","PeriodicalId":13052,"journal":{"name":"IEEE Transactions on Green Communications and Networking","volume":"9 1","pages":"29-44"},"PeriodicalIF":5.3,"publicationDate":"2024-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Channel Estimation for RIS-Assisted Time-Varying MIMO System: An Attention-Based Learning Approach","authors":"Ziwei Qi;Da Liu;Jingbo Zhang","doi":"10.1109/TGCN.2024.3410049","DOIUrl":"https://doi.org/10.1109/TGCN.2024.3410049","url":null,"abstract":"The challenges of time-varying channel estimation in reconfigurable intelligent surface (RIS)-based MIMO systems are focused on in this paper. We propose a scheme based on deep learning, which includes RIS element selection model (RESM) and a full channel estimation model (FCEM). Firstly, The RESM is designed for choosing the optimal subset of all RIS elements to reduce system overhead. A convolutional network based scorer is established to evaluate relationship between optimal partial channels and full channels, and the differential Top-N operation is used to select the optimal subset of RIS elements, where perturbed maximum method is utilized to ensure end-to-end learning is feasible. Then, the FCEM is developed to realize accurate time-varying channel estimation by exploiting the strong nonlinear fitting capability of attention based deep networks. We develop network structures including improved transformers and residual blocks in the FCEM to counteract the channels’ stochastic characteristic, so as to recover the full channels corresponding to the optimal subset. The numerical results demonstrate the proposed scheme outperforms the benchmark schemes under various comparison conditions and is suitable for high-speed mobile scenarios.","PeriodicalId":13052,"journal":{"name":"IEEE Transactions on Green Communications and Networking","volume":"9 1","pages":"140-151"},"PeriodicalIF":5.3,"publicationDate":"2024-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}