Article
Engineering, Electrical & Electronic
Wanli Ni, Xiao Liu, Yuanwei Liu, Hui Tian, Yue Chen
Summary: This article introduces a novel resource allocation framework for multi-cell intelligent reflecting surface (IRS) aided non-orthogonal multiple access (NOMA) networks. Numerical results demonstrate the significant increase in network sum rate with the use of IRS, higher energy efficiency of proposed algorithms for multi-cell IRS-aided NOMA networks, and the ability to adjust the balance between coverage area and spectrum efficiency by selecting the location of the IRS.
IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS
(2021)
Article
Chemistry, Analytical
Zhengjia Xu, Ivan Petrunin, Teng Li, Antonios Tsourdos
Summary: This paper proposes three heuristic solutions, namely stochastic algorithm, GRASP, and SSD, to achieve dynamic power and channel allocation for users in the downlink multi-channel non-orthogonal multiple access systems. Multiple constraints are considered based on practical scenarios, and the effectiveness and performance of the algorithms are compared through demonstration and simulation.
Article
Computer Science, Hardware & Architecture
Xin Liu, Kwok-Yan Lam, Feng Li, Jun Zhao, Li Wang, Tariq S. Durrani
Summary: The explosive growth of bandwidth-hungry Internet applications has driven the rapid development of new generation mobile network technologies, such as 6G networks and high-throughput satellite communication services, to achieve pervasive broadband access to the Internet. The integration of satellite-terrestrial communication networks (ISTCNs) aims to provide high-speed and pervasive network access by integrating terrestrial mobile networks with satellite communication systems. Effective spectrum management techniques, such as non-orthogonal multiple access (NOMA) and cognitive radio (CR), are needed to reduce congestion and interference in spectrum sharing for ISTCNs.
Article
Engineering, Electrical & Electronic
Qiulei Huang, Wei Wang, Weidang Lu, Nan Zhao, Arumugam Nallanathan, Xianbin Wang
Summary: This paper proposes a scheme that combines NOMA and UAV to achieve better performance for wireless networks. It addresses the challenge of effective resource allocation for QoS provision in multi-cluster NOMA-UAV networks. The proposed scheme includes user clustering, optimal routing, and joint optimization of transmission power, hovering locations, and transmission duration. The non-convex problem is decomposed into three subproblems, with power and location optimizations transformed into convex problems. The duration optimization is solved directly as a linear programming problem. An iterative algorithm is then proposed to solve these subproblems alternately, and simulation results show the effectiveness of the proposed scheme.
IEEE TRANSACTIONS ON COMMUNICATIONS
(2022)
Article
Engineering, Electrical & Electronic
Sabyasachi Gupta, Dinesh Rajan, Joseph Camp
Summary: This article proposes a novel framework for a multi-user mobile edge computing (MEC) network, where users with high downlink rate demands and users with intensive computation tasks can collaborate to reduce task completion time and improve downlink user rates. By using non-orthogonal multiple access (NOMA), the users with computation tasks can offload part of the tasks to the edge cloud and the downlink users, while forwarding information received from the base station (BS) to the downlink users. A joint optimization of communication and computational resources, user pairings, task sharing, and relay bits is performed to minimize task completion time and satisfy downlink user incentives. Simulation results demonstrate significant reductions in task completion time and computational energy savings at the edge cloud, as well as improved downlink user rates compared to orthogonal transmission.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Sepehr Rezvani, Eduard Axel Jorswieck, Nader Mokari Yamchi, Mohammad Reza Javan
Summary: In this work, a globally optimal joint successive interference cancellation ordering and power allocation algorithm is proposed for maximizing the sum-rate in downlink multi-cell non-orthogonal multiple access systems. The algorithm utilizes the exploration of base station power consumption and obtains closed-form optimal powers for each cell. Additionally, low-complexity near-optimal joint rate and power allocation strategies are proposed for suboptimal decoding orders. Numerical results demonstrate the superiority of the proposed algorithms compared to other methods.
IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS
(2022)
Article
Computer Science, Hardware & Architecture
Zhong Yang, Yaru Fu, Yuanwei Liu, Yue Chen, Junshan Zhang
Summary: This article explores the utilization of artificial intelligence techniques to solve challenges in non-orthogonal multiple access-enabled fog radio access networks (NOMA-F-RANs). The architecture of NOMA-F-RANs and the potential applications of AI-driven techniques are elaborated. Case studies demonstrate the efficacy of AI-enabled methods in feature extraction and cooperative caching. Future trends of AI-driven NOMA-F-RANs, including research issues and challenges, are identified.
IEEE WIRELESS COMMUNICATIONS
(2022)
Article
Computer Science, Hardware & Architecture
Zhong Yang, Yaru Fu, Yuanwei Liu, Yue Chen, Junshan Zhang
Summary: This article discusses how artificial intelligence techniques can be used to solve the challenges in NOMA-F-RANs, including introducing the architecture and key modules, reviewing potentially applicable AI techniques, and demonstrating the effectiveness of AI methods through case studies. Future trends include identifying open research issues and challenges.
IEEE WIRELESS COMMUNICATIONS
(2022)
Article
Engineering, Electrical & Electronic
Ziad Qais Al-Abbasi, Khaled M. Rabie, Daniel K. C. So
Summary: This paper investigates the energy efficiency optimization of a two-tier CRAN downlink based on NOMA, using PPP distribution for base station number and locations, and proposing an optimized solution and two power allocation techniques. Simulation results demonstrate promising performance gains compared to existing approaches.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2021)
Article
Chemistry, Analytical
Jie Zeng, Jiaying Sun, Yuxin Song, Jiajia Mei, Tiejun Lv, Shidong Zhou
Summary: This paper focuses on a user-centered NOMA collaboration system in an ultra-dense network and proposes two algorithms, a dynamic packet matching algorithm and an iterative algorithm based on convex functions. These algorithms improve system throughput while ensuring user quality of service.
Article
Computer Science, Hardware & Architecture
Zhilan Wan, Ding Xu, Dahu Xu, Ishtiaq Ahmad
Summary: This paper investigates a NOMA-based multi-access MEC system, where optimization of MEC servers, users, transmit power, computation resource, time, and channel allocations to minimize overall task delay is considered. A heuristic algorithm is proposed to solve the problem, outperforming benchmark algorithms according to extensive simulations.
Article
Telecommunications
Guoquan Li, Zijie Hong, Yu Pang, Yongjun Xu, Zhengwen Huang
Summary: In this paper, a MIMO-NOMA system based on spatial modulation is proposed to achieve higher spectral efficiency. By investigating a resource allocation problem and employing graph theory and auxiliary variable method, an improved algorithm is proposed and demonstrated to outperform traditional methods through simulation.
DIGITAL COMMUNICATIONS AND NETWORKS
(2022)
Article
Computer Science, Information Systems
Haitham Al-Obiedollah, Kanapathippillai Cumanan, Haythem Bany Salameh, Gaojie Chen, Zhiguo Ding, Octavia A. Dobre
Summary: The MC-NOMA system divides the available bandwidth into sub-bands and serves multiple users in each sub-band using non-orthogonal multiple access. A technique for jointly allocating power and bandwidth with opportunistic sharing between sub-bands is proposed, utilizing a second-order cone program to address non-convexity issues in optimization. Simulation results demonstrate that the MC-NOMA system with opportunistic bandwidth allocation outperforms schemes with equal bandwidth allocation in terms of achieved sum-rate.
IEEE WIRELESS COMMUNICATIONS LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Meng Wang, Shuo Shi, Deyou Zhang, Chenyu Wu, Ye Wang
Summary: This paper investigates the resource allocation and computation offloading problem in multi-access edge computing (MEC) systems with non-orthogonal multiple access. It proposes a two-layer iterative method to jointly optimize the offloading ratio, computational frequency, and transmit precoding matrix of each mobile user (MU) in order to minimize energy consumption and satisfy latency constraints. The optimal decoding order of MUs is discussed under different scenarios, and a metric is proposed to balance the effects of channel conditions and latency requirements. Simulation results demonstrate the proposed method's convergence and superiority over benchmark algorithms.
IEEE TRANSACTIONS ON COMMUNICATIONS
(2023)
Article
Computer Science, Information Systems
Minh Tri Nguyen, Long Bao Le
Summary: In this work, we study the joint optimization of multiple UAVs' trajectories, power allocation, user-UAV association, and user pairing for UAV-assisted wireless networks using NOMA for uplink communications. The goal is to minimize energy consumption while ensuring successful data transmission. We propose an iterative algorithm to solve the optimization problem, leveraging the BCD method and SCA method. Numerical results demonstrate the efficiency of our proposed algorithm.
IEEE INTERNET OF THINGS JOURNAL
(2022)
Article
Engineering, Electrical & Electronic
Tan N. Nguyen, Dinh-Hieu Tran, Trinh Van Chien, Van-Duc Phan, Nhat-Tien Nguyen, Miroslav Voznak, Symeon Chatzinotas, Bjorn Ottersten, H. Vincent Poor
Summary: This article investigates the physical layer security with radio frequency energy harvesting in a simultaneous wireless information and power transfer cooperative network. A low-complexity sensor source selection scheme is proposed, and two relaying strategies are considered. Analytical expressions for the outage probability and intercept probability are derived, and simulation results show the superiority of the proposed scheme.
IEEE SENSORS JOURNAL
(2023)
Article
Engineering, Electrical & Electronic
Jie Cao, Xu Zhu, Sumei Sun, Yufei Jiang, Zhongxiang Wei, Vincent K. N. Lau
Summary: Multiplexing or transmission diversity via dual links can reduce the age of information (AoI). This study tackles the issue of selecting between the two transmission modes for an AoI-oriented short-packet system over fading channels. Closed-form expressions for average AoI and peak AoI (PAoI) are derived based on a discrete-time Markov chain process. The study also analyzes the signal-to-noise ratio (SNR) threshold for transmission mode selection, the monotonicity of PAoI gains by multiplexing and diversity, and their achievable gains.
IEEE TRANSACTIONS ON COMMUNICATIONS
(2023)
Article
Engineering, Electrical & Electronic
Trinh Van Chien, Eva Lagunas, Tung Hai Ta, Symeon Chatzinotas, Bjorn Ottersten
Summary: This article discusses multi-beam high throughput satellite (HTS) systems where all beams reuse the same spectrum. A novel user scheduling and power allocation design is proposed to provide guarantees in terms of the individual QoS requirements while maximizing the system throughput under a limited power budget. The effectiveness of the algorithms on GEO satellite networks is demonstrated through numerical results, showing better QoS satisfaction combined with outstanding overall system throughput.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Ronghong Mo, Yiyang Pei, Neelakantam V. Venkatarayalu, Pereira Nathaniel Joseph, A. Benjamin Premkumar, Sumei Sun, Simon Kok Kan Foo
Summary: This paper proposes an online unsupervised deep machine learning algorithm for outlier detection in time series data with seasonality and trend effects. The algorithm utilizes a neural network based on temporal convolution and autoencoder for reconstruction and uses reconstruction errors for outlier detection. It addresses the presence of outliers in the training data through a two-step training process and a specially designed loss function that captures the seasonality and trend effects. The algorithm also employs a pre-processing technique to mitigate false alarms caused by trend effects.
IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS
(2023)
Article
Computer Science, Hardware & Architecture
Jie Cao, Xu Zhu, Sumei Sun, Zhongxiang Wei, Yufei Jiang, Jingjing Wang, Vincent K. N. Lau
Summary: Industrial metaverse aims to create an immersive virtual space that interacts with physical space, enhancing operation and process efficiency. Short-packet communication plays a significant role in data exchange, requiring high reliability and low latency. Achieving an immersive and interactive industrial metaverse is challenging due to strict communication requirements and limited resources. This study investigates the coupling relationships of Key Performance Indicators (KPIs) in 6G URLLC and explores the potential of optimizing short-packet structure to improve these KPIs. The co-design of sensing, communication, control, and computing is proposed to realize real-time intelligence, and future research directions are discussed.
IEEE WIRELESS COMMUNICATIONS
(2023)
Article
Chemistry, Analytical
Yuhong Wang, Yonghong Zeng, Sumei Sun, Peng Hui Tan, Yugang Ma, Ernest Kurniawan
Summary: We proposed two methods, the RSSI ratio fingerprint method and the model-based RSSI ratio algorithm, for localizing drone controllers based on received signal strength indicator (RSSI) ratios. Through simulations and field trials, we found that our methods outperformed existing algorithms in WLAN channels. Increasing the number of sensors and averaging RSSI ratio samples improved performance in certain propagation channels. However, this improvement was not significant in channels with location-dependent fading effects. Our methods provided effective localization solutions for drone controllers using RSSI ratios.
Article
Computer Science, Information Systems
Anastasios Papazafeiropoulos, Cunhua Pan, Ahmet M. M. Elbir, Van-Dinh Nguyen, Pandelis Kourtessis, Symeon Chatzinotas
Summary: This paper focuses on maximizing the uplink minimum signal-to-interference-plus-noise ratio (SINR) in a general multiple-input single-output (MISO) system assisted by an intelligent reflecting surface (IRS) with hardware impairments. By jointly optimizing the receiver, transmit power, and reflecting beamforming matrix, the asymptotic weighted maximum-minimum SINR with hardware impairments is derived. Monte Carlo simulations verify the analytical results and show the interplay among key parameters and the performance degradation caused by hardware impairments.
IEEE WIRELESS COMMUNICATIONS LETTERS
(2023)
Article
Computer Science, Information Systems
Ahmet M. Elbir, Symeon Chatzinotas
Summary: The Terahertz (THz) band, with its ultra-wide bandwidth and narrow beamwidth, is considered for the development of the sixth generation wireless networks. However, THz-band transmission faces challenges such as beam-splitting, where the beams generated at different subcarriers split and point in different directions. An approach called beam-split-aware orthogonal matching pursuit (BSA-OMP) is proposed to efficiently estimate the THz channel and beamformer design without additional hardware. Numerical results show that the BSA-OMP approach outperforms existing state-of-the-art techniques.
IEEE WIRELESS COMMUNICATIONS LETTERS
(2023)
Article
Telecommunications
Konstantinos Ntontin, Alexandros-Apostolos A. Boulogeorgos, Emil Bjornson, Wallace Alves Martins, Steven Kisseleff, Sergi Abadal, Eduard Alarcon, Anastasios Papazafeiropoulos, Fotis I. Lazarakis, Symeon Chatzinotas
Summary: In this paper, the feasibility of fully-energy-autonomous operation of reconfigurable intelligent surfaces (RIS) through wireless energy harvesting (EH) is examined. A suitable energy-consumption model is proposed, based on the integrated controller architecture, to identify the main RIS energy-consuming components and include the energy consumption needed for channel estimation. A novel RIS architecture is introduced, enabling EH through RIS unit-cell (UC) splitting. An EH policy is presented, where a subset of the UCs is used for beamsteering while the remaining UCs absorb energy. The results demonstrate the feasibility of the proposed architecture and the efficiency of the presented algorithms.
IEEE TRANSACTIONS ON GREEN COMMUNICATIONS AND NETWORKING
(2023)
Article
Telecommunications
Steven Kisseleff, Symeon Chatzinotas
Summary: This article describes a multi-user quantum key distribution (QKD) system based on free-space optics (FSO) in a terrestrial environment. FSO-QKD is heavily affected by obstacles in the signal path, leading to decoherence and other harmful effects. Trusted nodes (TNs) are introduced to the QKD network to avoid performance degradation. However, with no alternative signal routes, the same TN relays both the classical data and quantum key, making it a potential target for eavesdropping. To address this issue, the use of a trusted reconfigurable intelligent surface (RIS) is explored, which passively reflects classical signals and manipulates them to align with the distributed keys. Numerical simulations with multiple FSO-QKD users and an eavesdropper demonstrate that the proposed concept provides high levels of data protection even in the event of a successful attack on the trusted RIS and complete key acquisition by the eavesdropper.
IEEE COMMUNICATIONS LETTERS
(2023)
Article
Engineering, Civil
Wali Ullah Khan, Muhammad Ali Jamshed, Eva Lagunas, Symeon Chatzinotas, Xingwang Li, Bjorn Ottersten
Summary: This paper proposes a new optimization framework for energy-efficient transmission in AmBC enhanced NOMA cooperative vehicle-to-everything (V2X) networks. By optimizing power allocation and reflection coefficient, the total transmit power of the network is minimized while ensuring individual quality of services.
IEEE TRANSACTIONS ON INTELLIGENT TRANSPORTATION SYSTEMS
(2023)
Article
Engineering, Electrical & Electronic
Anastasios Papazafeiropoulos, Ahmet M. Elbir, Pandelis Kourtessis, Ioannis Krikidis, Symeon Chatzinotas
Summary: Reconfigurable intelligent surface (RIS) is a cost-effective and promising solution to extend wireless signal coverage and improve performance. This paper proposes a cooperative double-RIS with simultaneously transmitting and reflecting RIS (STAR-RIS) architecture, denoted as RIS/STAR-RIS, under correlated Rayleigh fading conditions, to assist communication in a massive multiple-input multiple-output (mMIMO) setup.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2023)
Article
Telecommunications
Hayder Al-Hraishawi, Osamah Abdullah, Symeon Chatzinotas, Bjorn Ottersten
Summary: This paper investigates the concept of utilizing an unconventional source for RF energy harvesting in multi-user massive MIMO systems. The feasibility of this concept is studied through system performance analysis, and the effectiveness of the derived closed-form expressions is validated through simulations. The results show that using jamming signals for energy harvesting is viable and can improve the performance of massive MIMO systems.
IEEE TRANSACTIONS ON GREEN COMMUNICATIONS AND NETWORKING
(2023)
Article
Engineering, Electrical & Electronic
Chandan Kumar Sheemar, Sourabh Solanki, Jorge Querol, Sumit Kumar, Symeon Chatzinotas
Summary: Intelligent reflecting surfaces (IRS) have emerged as a promising technology to enhance wireless communication systems. The integration of IRS with full-duplex (FD) communication has garnered significant attention due to its potential to improve spectral and energy efficiencies further. IRS-assisted FD systems combine the benefits of both technologies and provide a powerful solution for the next generation of cellular systems.
IEEE OPEN JOURNAL OF THE COMMUNICATIONS SOCIETY
(2023)
Article
Engineering, Electrical & Electronic
Mahdis Jalali, Flor Ortiz, Eva Lagunas, Steven Kisseleff, Luis Emiliani, Symeon Chatzinotas
Summary: The number of NGSO satellite constellations is increasing, which will inevitably cause co-channel interference with GSO networks, affecting the operation of both NGSO and GSO satellites. To protect GSO systems from interference, ITU has established regulations for emitted power flux-densities from NGSO systems. We propose a joint power and tilt control strategy to maximize user demand satisfaction and ensure compliance with ITU limits, reducing interference levels and improving service continuity.
IEEE OPEN JOURNAL OF VEHICULAR TECHNOLOGY
(2023)