Physical layer security is an emerging technique for improving wireless communication security, which is widely regarded as a complement to cryptographic technologies. To design physical layer security techniques for ...Physical layer security is an emerging technique for improving wireless communication security, which is widely regarded as a complement to cryptographic technologies. To design physical layer security techniques for practical scenarios, uncertainty and imperfections in the channel knowledge need to be taken into account. This paper is a survey of recent research on physical layer security that considers imperfect channel state information （CSI） at communication nodes. We first give an overview of the main information-theoretic measures of secrecy performance with imperfect CSI. Then, we describe several signal processing enhancements in secure transmission designs. These enhancements include secure on-off transmission, beamforming with artificial noise, and secure communication assisted by relay nodes or in cognitive radio systems. Recent studies of physical layer security in large-scale decentralized wireless networks are also summarized. Finally, open problems for on-going and future research are discussed.展开更多
The escalating costs of research and development, coupled with the influx of researchers, have led to a surge in published articles across scientific disciplines. However, concerns have arisen regarding the accuracy, ...The escalating costs of research and development, coupled with the influx of researchers, have led to a surge in published articles across scientific disciplines. However, concerns have arisen regarding the accuracy, validity, and reproducibility of reported findings. Issues such as replication problems, fraudulent practices, and a lack of expertise in measurement theory and uncertainty analysis have raised doubts about the reliability and credibility of scientific research. Rigorous assessment practices in certain fields highlight the importance of identifying potential errors and understanding the relationship between technical parameters and research outcomes. To address these concerns, a universally applicable criterion called comparative certainty is urgently needed. This criterion, grounded in an analysis of the modeling process and information transmission, accumulation, and transformation in both theoretical and applied research, aims to evaluate the acceptable deviation between a model and the observed phenomenon. It provides a theoretically grounded framework applicable to all scientific disciplines adhering to the International System of Units (SI). Objective evaluations based on this criterion can enhance the reproducibility and reliability of scientific investigations, instilling greater confidence in published findings. Establishing this criterion would be a significant stride towards ensuring the robustness and credibility of scientific research across disciplines.展开更多
This paper proposes a novel optimization scheme to support stable and reliable vehicle-to-everything connections in two-tier networks,where the uplink channel of the cellular user is reused by underlay vehicle-to-vehi...This paper proposes a novel optimization scheme to support stable and reliable vehicle-to-everything connections in two-tier networks,where the uplink channel of the cellular user is reused by underlay vehicle-to-vehicle communications.However,considering complex channel fading and high-speed vehicle movement,the cer-tainty assumption is impractical and fails to maintain power control strategy in reality in the traditional statical vehicular networks.Rather than the perfect channel state information assumption,the first-order Gauss-Markov process which is a probabilistic model affected by vehicle speed and fading is introduced to describe imperfect channel gains.Moreover,interference management is a major challenge in reusing communications,especially in uncertain channel environments.Power control is an effective way to realize interference management,and optimal power allocation can ensure that interference of the user meets the communication requirements.In this study,the sum-rate-oriented power control scheme and minimum-rate-oriented power control scheme were implemented to manage interference and satisfy different design objectives.Since both of these schemes are non-convex and intractable,the Bernstein approximation and successive convex approximation methods were adopted to transform the original problems into convex ones.Furthermore,a novel distributed robust power control al-gorithm was developed to determine the optimal solutions.The performance of the algorithm was evaluated through numerical simulations,and the results indicate that the proposed algorithm is effective in vehicular communication networks with uncertain channel environments.展开更多
文摘Physical layer security is an emerging technique for improving wireless communication security, which is widely regarded as a complement to cryptographic technologies. To design physical layer security techniques for practical scenarios, uncertainty and imperfections in the channel knowledge need to be taken into account. This paper is a survey of recent research on physical layer security that considers imperfect channel state information （CSI） at communication nodes. We first give an overview of the main information-theoretic measures of secrecy performance with imperfect CSI. Then, we describe several signal processing enhancements in secure transmission designs. These enhancements include secure on-off transmission, beamforming with artificial noise, and secure communication assisted by relay nodes or in cognitive radio systems. Recent studies of physical layer security in large-scale decentralized wireless networks are also summarized. Finally, open problems for on-going and future research are discussed.
文摘The escalating costs of research and development, coupled with the influx of researchers, have led to a surge in published articles across scientific disciplines. However, concerns have arisen regarding the accuracy, validity, and reproducibility of reported findings. Issues such as replication problems, fraudulent practices, and a lack of expertise in measurement theory and uncertainty analysis have raised doubts about the reliability and credibility of scientific research. Rigorous assessment practices in certain fields highlight the importance of identifying potential errors and understanding the relationship between technical parameters and research outcomes. To address these concerns, a universally applicable criterion called comparative certainty is urgently needed. This criterion, grounded in an analysis of the modeling process and information transmission, accumulation, and transformation in both theoretical and applied research, aims to evaluate the acceptable deviation between a model and the observed phenomenon. It provides a theoretically grounded framework applicable to all scientific disciplines adhering to the International System of Units (SI). Objective evaluations based on this criterion can enhance the reproducibility and reliability of scientific investigations, instilling greater confidence in published findings. Establishing this criterion would be a significant stride towards ensuring the robustness and credibility of scientific research across disciplines.
基金supported by National Natural Science Foundation of China under grant 61873223,61803328the Natural Science Foundation of Hebei Province under grant F2019203095Beijing Natural Science Foundation under grant L201002.
文摘This paper proposes a novel optimization scheme to support stable and reliable vehicle-to-everything connections in two-tier networks,where the uplink channel of the cellular user is reused by underlay vehicle-to-vehicle communications.However,considering complex channel fading and high-speed vehicle movement,the cer-tainty assumption is impractical and fails to maintain power control strategy in reality in the traditional statical vehicular networks.Rather than the perfect channel state information assumption,the first-order Gauss-Markov process which is a probabilistic model affected by vehicle speed and fading is introduced to describe imperfect channel gains.Moreover,interference management is a major challenge in reusing communications,especially in uncertain channel environments.Power control is an effective way to realize interference management,and optimal power allocation can ensure that interference of the user meets the communication requirements.In this study,the sum-rate-oriented power control scheme and minimum-rate-oriented power control scheme were implemented to manage interference and satisfy different design objectives.Since both of these schemes are non-convex and intractable,the Bernstein approximation and successive convex approximation methods were adopted to transform the original problems into convex ones.Furthermore,a novel distributed robust power control al-gorithm was developed to determine the optimal solutions.The performance of the algorithm was evaluated through numerical simulations,and the results indicate that the proposed algorithm is effective in vehicular communication networks with uncertain channel environments.
