Article
Engineering, Electrical & Electronic
Ishtiaq Ahmad, Khoa D. Nguyen, Nick Letzepis, Gottfried Lechner, Vahid Joroughi
Summary: This paper investigates the application of zero-forcing (ZF) precoding in reducing interbeam interference in the forward link. By designing a ZF precoder with partial CSI and analyzing its performance, the study considers the impact of rain fading attenuation on the link, providing valuable insights and numerical analysis of the precoder's robustness to CSI estimation errors.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2021)
Article
Engineering, Electrical & Electronic
Zining Wang, Min Lin, Shiyong Sun, Ming Cheng, Wei-Ping Zhu
Summary: This paper proposes a downlink transmission scheme that combines robust beamforming and non-orthogonal multiple access for multibeam satellite systems. The scheme aims to enhance spectral efficiency and user fairness. By utilizing imperfect channel state information and considering fairness among multiple satellite terminals, an optimization problem is formulated to maximize the sum fair utility while meeting transmit power budget and quality-of-service requirements. The non-convex problem is solved using a discretization method and an iterative penalty function algorithm. Simulation results demonstrate the effectiveness and superiority of the proposed scheme in achieving a balance between system performance and user fairness.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Yanhao Liu, Yibiao Wang, Jue Wang, Li You, Wenjin Wang, Xiqi Gao
Summary: This paper investigates the design of precoder for LEO satellite downlinks with imperfect AoD-based CSI. The angle deviations of each user are treated as random variables and integrated to enhance the robustness of the precoder. A per-antenna power constraint is adopted instead of a sum-power constraint, and an iterative algorithm and deep learning techniques are used to reduce computational complexity. Simulation results demonstrate the effectiveness of the proposed precoding approach.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Alireza Haqiqatnejad, Farbod Kayhan, Bjorn Ottersten
Summary: This study tackles the symbol-level precoding design problem in a multiuser millimeter wave MIMO wireless system using a hybrid analog-digital architecture, aiming to minimize the Euclidean distance, achieve power savings in precoding, and substantially improve energy efficiency through phase shifter selection.
IEEE TRANSACTIONS ON COMMUNICATIONS
(2021)
Article
Engineering, Electrical & Electronic
Guangyang Zhang, Chao Shen, Bo Ai, Zhangdui Zhong
Summary: This paper investigates joint beamforming design in a multiuser MISO communication network aided with an intelligent reflecting surface (IRS). Symbol-level precoding (SLP) is adopted to enhance system performance by considering multiuser interference (MUI) and bounded channel uncertainty. Two algorithms based on semidefinite relaxation (SDR) and alternating optimization (AO) methods are proposed and compared for the single-user case. The AO-based algorithm shows lower computational complexity with similar power compared to the SDR-based algorithm. The AO technique is then applied to the multiuser case and an algorithm based on the proximal gradient descent (PGD) method is developed. Numerical results demonstrate that SLP can significantly improve system performance and 3-bit phase shifters can achieve near-optimal power performance.
IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS
(2022)
Article
Engineering, Electrical & Electronic
Zhi Wen Si, Longfei Yin, Bruno Clerckx
Summary: This paper studies the precoder design problem of achieving max-min fairness amongst users in multigateway multibeam satellite communication systems with feeder link interference. The proposed beamforming strategy is based on RSMA, and the MMF problem is formulated subject to per-antenna power constraints and imperfect CSIT, considering the case of two-stage precoding assisted by OBP. RSMA promises MMF rate gain, which increases when OBP is used, making it a promising solution for multigateway multibeam satellite systems facing practical challenges.
IEEE TRANSACTIONS ON COMMUNICATIONS
(2022)
Article
Telecommunications
Steven Kisseleff, Eva Lagunas, Tedros Salih Abdu, Symeon Chatzinotas, Bjorn Ottersten
Summary: This letter discusses the challenges encountered in the design of future broadband SatComs regarding radio resource management, and provides a comprehensive overview of available techniques, including demand-matching formulation of power and bandwidth assignment, and scheduling design in multibeam satellite systems. Future challenges and research topics are also described.
IEEE COMMUNICATIONS LETTERS
(2021)
Article
Telecommunications
Yi Xiao, Deepak Mishra, Jinhong Yuan, Yuyue Luo
Summary: This paper studies the proportionally fair beamforming design for the downlink channel of multibeam satellite systems. Robustness to imperfect channel state information is achieved through optimization with outage probability and power constraints. A proposed sub-optimal algorithm successfully solves the non-convex optimization problem and simulation results demonstrate performance gain over robust max-min schemes in different levels of phase uncertainty.
IEEE COMMUNICATIONS LETTERS
(2022)
Article
Telecommunications
Jian Zhang, Min Lin, Jian Ouyang, Wei-Ping Zhu, Tomaso De Cola
Summary: This letter proposes a robust beamforming scheme to enhance physical layer security of the downlink of a multibeam satellite system in the presence of eavesdroppers. The scheme aims to maximize the worst-case achievable secrecy rate of the legitimate user, subject to constraints of transmit power and quality of service requirements. By adopting discretization method and log-sum-exp function, the non-convex optimization problem is effectively addressed. The simulation results validate the effectiveness of the proposed robust beamforming algorithm in improving the security of multibeam satellite systems.
IEEE COMMUNICATIONS LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Ye Fan, Rugui Yao, Ang Li, Xuewen Liao, Victor C. M. Leung
Summary: This paper investigates the security problem of a multi-eavesdrop MISO wiretap channel and proposes a deception scheme via a random transmission strategy. Efficient algorithms for both perfect and imperfect CSI cases are provided for the deception optimization problem. Simulation results confirm the superiority of the proposed approach over traditional secure precoding schemes.
IEEE TRANSACTIONS ON COMMUNICATIONS
(2021)
Article
Computer Science, Information Systems
Erico S. P. Lopes, Lukas T. N. Landau
Summary: This letter presents two MMSE symbol-level precoding approaches with strict per antenna power constraint and PSK modulation for perfect and imperfect channel state information scenarios. The proposed designs are formulated as second-order cone programs and can be solved optimally using the interior point method. Numerical results demonstrate that the proposed designs outperform existing techniques in terms of bit-error-rate at low and intermediate signal-to-noise ratio in scenarios with perfect channel state information. Numerical evaluations also confirm the superiority of the proposed robust MMSE design in the presence of channel state information imperfection.
IEEE WIRELESS COMMUNICATIONS LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Longfei Yin, Bruno Clerckx
Summary: This work focuses on the Rate-Splitting Multiple Access (RSMA) and its beamforming design problem to achieve max-min fairness (MMF) among multiple co-channel multicast groups with imperfect channel state information at the transmitter (CSIT). RSMA relies on RS at the transmitter and SIC at the receivers, enabling a flexible framework for non-orthogonal transmission and robust interference management. The superiority of RS-based multigroup multicast beamforming compared with NoRS is demonstrated via simulations in both terrestrial and multibeam satellite systems.
IEEE TRANSACTIONS ON COMMUNICATIONS
(2021)
Article
Computer Science, Information Systems
Shu Cai, Heshuai Qu, Jun Zhang, Xiaoye Shi, Hongbo Zhu
Summary: This letter investigates an intelligent reflective surface (IRS) aided secure wireless communication system, where a multi-antenna base station (BS) transmits confidential messages to multiple users via symbol-level precoding (SLP). The study considers the cases where the eavesdropper has no channel state information (CSI) and global CSI and examines the worst and best eavesdropping performance and the security improvement brought by the joint SLP-IRS design.
IEEE WIRELESS COMMUNICATIONS LETTERS
(2022)
Article
Computer Science, Information Systems
Satya Chan, Hyein Lee, Sooyoung Kim, Daesub Oh
Summary: This letter proposes an efficient power and frequency resource allocation scheme for integrated satellite and terrestrial systems, aiming to minimize inter-component interference while providing maximum throughput to users. The simulation results demonstrate that the proposed scheme approximates the exhaustive search with reduced complexity.
IEEE WIRELESS COMMUNICATIONS LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Zhu Bo, Rang Liu, Ming Li, Qian Liu
Summary: This paper proposes a deep learning based symbol-level precoding design approach to optimize performance in multi-user multi-input single-output systems. Simulation results show that this method significantly reduces computing time compared to traditional methods, but may result in slight performance loss.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2021)
