This paper presents a design scheme of wire-line telephone system using self-interference(SI)cancellation technology in co-frequency co-time full-duplex(CCFD)system to realize absolute secure communication at the phys...This paper presents a design scheme of wire-line telephone system using self-interference(SI)cancellation technology in co-frequency co-time full-duplex(CCFD)system to realize absolute secure communication at the physical layer.This scheme can hide the target signal by skillfully releasing the high-power artificial noise to the whole link at the receiving node,and then make use of the receiver’s knowledge of the SI signal to achieve high dB SI cancellation with the help of analog domain SI cancellation technology in CCFD domain,so that the signal-to-noise ratio(SNR)received by the eavesdropper at any position of the link is far lower than that of the legitimate receiver,so as to realize the absolutely secure communication in the sense of Wyner principle.This paper not only puts forward the specific design scheme of absolutely secure communication telephone,but also analyzes the calculation of security capacity under different eavesdropping positions,different SI cancellation capability and different system parameters according to Shannon theory.展开更多
The task of detecting fraud in credit card transactions is crucial to ensure the security and stability of a financial system,as well as to enforce customer confidence in digital payment systems.Historically,credit ca...The task of detecting fraud in credit card transactions is crucial to ensure the security and stability of a financial system,as well as to enforce customer confidence in digital payment systems.Historically,credit card companies have used rulebased approaches to detect fraudulent transactions,but these have proven inadequate due to the complexity of fraud strategies and have been replaced by much more powerful solutions based on machine learning or deep learning algorithms.Despite significant progress,the current approaches to fraud detection suffer from a number of limitations:for example,it is unclear whether some transaction features are more effective than others in discriminating fraudulent transactions,and they often neglect possible correlations among transactions,even though they could reveal illicit behaviour.In this paper,we propose a novel credit card fraud detection(CCFD)method based on a transaction behaviour-based hierarchical gated network.First,we introduce a feature-oriented extraction module capable of identifying key features from original transactions,and such analysis is effective in revealing the behavioural characteristics of fraudsters.Second,we design a transaction-oriented extraction module capable of capturing the correlation between users’historical and current transactional behaviour.Such information is crucial for revealing users’sequential behaviour patterns.Our approach,called transactional-behaviour-based hierarchical gated network model(TbHGN),extracts two types of new transactional features,which are then combined in a feature interaction module to learn the final transactional representations used for CCFD.We have conducted extensive experiments on a real-world credit card transaction dataset with an increase in average F1 between 1.42%and 6.53%and an improvement in average AUC between 0.63%and 2.78%over the state of the art.展开更多
同时同频全双工(Co-time Co-frequency Full Duplex,CCFD)技术能够有效地解决当前频谱资源短缺的问题,理论上可以将频谱利用率和系统容量提升1倍,如何高效抑制自干扰信号是实现CCFD体制需要攻克的关键技术。从空间域、射频(Radio Freque...同时同频全双工(Co-time Co-frequency Full Duplex,CCFD)技术能够有效地解决当前频谱资源短缺的问题,理论上可以将频谱利用率和系统容量提升1倍,如何高效抑制自干扰信号是实现CCFD体制需要攻克的关键技术。从空间域、射频(Radio Frequency,RF)域、数字域3个方面对全双工自干扰抑制技术的研究现状进行了详细地梳理和归纳,并深入分析了当前研究存在的缺陷和不足,并从技术发展和应用两个角度对CCFD技术的发展趋势进行了展望。展开更多
在同时同频全双工(CCFD)中,基站发射、接收通道非线性引入的附加干扰以及基站周围环境的变化,会影响数字域自干扰信道估计精度。该文提出了一种变窗长离散傅里叶变换信道估计算法,算法根据实际自干扰信道特征选取最优干扰抑制窗长,提高...在同时同频全双工(CCFD)中,基站发射、接收通道非线性引入的附加干扰以及基站周围环境的变化,会影响数字域自干扰信道估计精度。该文提出了一种变窗长离散傅里叶变换信道估计算法,算法根据实际自干扰信道特征选取最优干扰抑制窗长,提高自干扰信道的估计精度。仿真结果表明:在自干扰信道为莱斯信道,干噪比为15 d B时,采用该算法的数字自干扰抑制能力为22 d B,比采用最小二乘信道估计高7 d B,比采用固定窗长离散傅里叶变换信道估计高3 d B。展开更多
基金Supported by the Natural Science Foundation of Hubei Province(2019CFB593)the National Natural Science Foundation of China(61961016)+1 种基金Ph.D.Research Start-up Foundation of Hubei Minzu University(MY2018B08)Graduate Education Innovation Plan of Hubei Minzu University(DC2000000119)。
文摘This paper presents a design scheme of wire-line telephone system using self-interference(SI)cancellation technology in co-frequency co-time full-duplex(CCFD)system to realize absolute secure communication at the physical layer.This scheme can hide the target signal by skillfully releasing the high-power artificial noise to the whole link at the receiving node,and then make use of the receiver’s knowledge of the SI signal to achieve high dB SI cancellation with the help of analog domain SI cancellation technology in CCFD domain,so that the signal-to-noise ratio(SNR)received by the eavesdropper at any position of the link is far lower than that of the legitimate receiver,so as to realize the absolutely secure communication in the sense of Wyner principle.This paper not only puts forward the specific design scheme of absolutely secure communication telephone,but also analyzes the calculation of security capacity under different eavesdropping positions,different SI cancellation capability and different system parameters according to Shannon theory.
基金supported in part by the National Natural Science Foundation of China(61972241)the Natural Science Foundation of Shanghai(24ZR1427500,22ZR1427100)+1 种基金the Key Projects of Natural Science Research in Anhui Higher Education Institutions(2022AH051909)Bengbu University 2021 High-Level Scientific Research and Cultivation Project(2021pyxm04).
文摘The task of detecting fraud in credit card transactions is crucial to ensure the security and stability of a financial system,as well as to enforce customer confidence in digital payment systems.Historically,credit card companies have used rulebased approaches to detect fraudulent transactions,but these have proven inadequate due to the complexity of fraud strategies and have been replaced by much more powerful solutions based on machine learning or deep learning algorithms.Despite significant progress,the current approaches to fraud detection suffer from a number of limitations:for example,it is unclear whether some transaction features are more effective than others in discriminating fraudulent transactions,and they often neglect possible correlations among transactions,even though they could reveal illicit behaviour.In this paper,we propose a novel credit card fraud detection(CCFD)method based on a transaction behaviour-based hierarchical gated network.First,we introduce a feature-oriented extraction module capable of identifying key features from original transactions,and such analysis is effective in revealing the behavioural characteristics of fraudsters.Second,we design a transaction-oriented extraction module capable of capturing the correlation between users’historical and current transactional behaviour.Such information is crucial for revealing users’sequential behaviour patterns.Our approach,called transactional-behaviour-based hierarchical gated network model(TbHGN),extracts two types of new transactional features,which are then combined in a feature interaction module to learn the final transactional representations used for CCFD.We have conducted extensive experiments on a real-world credit card transaction dataset with an increase in average F1 between 1.42%and 6.53%and an improvement in average AUC between 0.63%and 2.78%over the state of the art.
文摘同时同频全双工(Co-time Co-frequency Full Duplex,CCFD)技术能够有效地解决当前频谱资源短缺的问题,理论上可以将频谱利用率和系统容量提升1倍,如何高效抑制自干扰信号是实现CCFD体制需要攻克的关键技术。从空间域、射频(Radio Frequency,RF)域、数字域3个方面对全双工自干扰抑制技术的研究现状进行了详细地梳理和归纳,并深入分析了当前研究存在的缺陷和不足,并从技术发展和应用两个角度对CCFD技术的发展趋势进行了展望。
文摘在同时同频全双工(CCFD)中,基站发射、接收通道非线性引入的附加干扰以及基站周围环境的变化,会影响数字域自干扰信道估计精度。该文提出了一种变窗长离散傅里叶变换信道估计算法,算法根据实际自干扰信道特征选取最优干扰抑制窗长,提高自干扰信道的估计精度。仿真结果表明:在自干扰信道为莱斯信道,干噪比为15 d B时,采用该算法的数字自干扰抑制能力为22 d B,比采用最小二乘信道估计高7 d B,比采用固定窗长离散傅里叶变换信道估计高3 d B。
